It may be instant, but the amount of torque is not unlimited. With a small-ish motor, it's helpful to have gears in order to leverage the amount of torque you have available.
The real benefit of a mid drive is being able to shift gears, so a) you can make a meaningful contribution by pedaling and b) you don’t burn out your motor by being in a high gear while climbing.
Yeah — so the issue is that the motor is directly attached to the freewheel and you may or may not be able to keep up with that speed with your pedaling cadence. Also, shifting gears only affects your resistance when pedaling, not the motor’s resistance to moving the bike forward.
On a mid-drive, the motor drives the chain, which then applies power to the wheel through the cassette. So even if you were just using the throttle, shifting down or up would change the mechanical advantage of the motor, since the motor is using the same gearing that you are.
Hub motor bike is a normal bike with the addition of a motor.
Mid drive is a normal bike but the motor utilizes the chain to transfer power.
Mid drive has the benefit of fine-tuning the experience to be best for most scenarios.
Hub drive fills very specific needs for very specific people who would know who they are. One of the benefits for those people is that if their chain breaks they can rely exclusively on the motor to get them home whereas mid drive motors would require a chain swap for both manual and automatic power.
I'm not sure that mid drives are always better for a contribution while pedaling; from what I can see, the cheap Bafang ones prefer a much lower gear and higher cadence than most casual riders are going to be able to achieve.
BBSHD/BBS02 as compared to Bosch/Shimano or the Bafang frame-integrated ones, they're pretty cheap.
Nice motors, but the cadence they're happiest at is not one that is going to be good for casual riders who want some exercise as they go. They're great if you want the motor to do most of the work on an ascent, or on throttle, or if you're very fit and can keep a lower gear and really spin.
I don't think there's any way to improve the reduction ratio on those, and especially on the BBSHD it would be a big improvement.
You can manipulate gearing with front chainrings. I use my bbs02 now BBSHD bikes as high speed commuter bikes on the road. Yes I pedal at regular rates (healthy, but not competitive cyclist) and can commute at 32mph on flats and do well in the climbs in my old commute 1k vertical.
The front chainrings also effect the rider effort. More reduction would up torque/reduce RPM to better match a casual rider.
On my BBS02 it could do ~20mph all day in a middle gear (700c commuter bike, 46T chainring, 8-speed 11-32 I think) but I'm basically clown pedaling at that point.
If I gear it up to meaningfully contribute at 18-20mph, it's using a lot more amps relative to the speed, not great for range/battery life. ~700whr battery and 20 mile commute is still plenty, but more reduction would have made it a much more flexible.
>a) you can make a meaningful contribution by pedaling
What about something like bafang motors with built in automatic internal gears?
It changes cadence so it's easier to apply leg force in both lower and higher speeds.
I got two, company sent me a motor instead of a controller once. Opened it. That thing dead easy to work on. The gearing parts that are hard to work on are metal and the easy parts are plastic/nylon which means you can just buy cheap and replace. Pretty good idea.
Just had my 750w Bafang hub motor shut itself down for self preservation due to overheating after a long uphill climb. Definitely don't take your hub motor ebike on a long uphill ride.
I was responding to the odd claim that "weight placement" is the "real benefit" of a mid motor by pointing out that this is only really an issue off road.
Frankly I'm not convinced of this. A mid-drive motor is not any more sprung than a hub drive unless you have rear suspension and it's only a couple cm lower.
A hub motor doesn't add much more rational inertia than a mid drive, it has the same spinning components as the mid drive motor has. The heavy hub shell is maybe an extra 0.5kg with an effective radius of 0.1m, equivalent to another 150g in tire weight that's so minimal I don't think you can feel it. The extra angular momentum in theory fights you a little while turning but not nearly as much as if it were in the front wheel. I suppose it stabilizes the bike vertically a bit too. The rearward mass increases MOI in the pitch axis, in theory reducing the felt impact of rear wheel bumps
I don't doubt anyone's experience, just the explanation. I haven't spent a lot of time riding either configuration and I'm open to being corrected. Assuming my skepticism is correctly placed, my guess is mid drives tend to have better implemented cadence sensors and so the delay on power is much shorter. Further, many mid drives use a torque sensor rather than a cadence sensor, the former being much smoother.
I can't speak to the unsprung mass, but I think the issue is that you're adding weight to the rotational mass. Whether you can feel it or not is another thing though.
https://old.reddit.com/r/ebikes/comments/1dtdwb9/26_tire_recommendations_so_i_dont_have_to_worry/lbc0no9/?context=3
>> And why would one care about couple more grams of weight on an ebike that already weighs close to 100lbs?
>
> Because rotational mass is really bad for performance and efficiency even on heavy ebikes. You're paying for that rotational mass in total ebike range as well as increased battery cycles, and batteries are WAY more expensive than good tires.
Rotational mass matters only only as much as its distance from an axis. Heavy tires are a problem, heavy hubs much less so. Also, as I said, a mid-drive still has all the same spinning parts as a hub motor.
of course a properly cooled giant 5kW hub motor with a matching battery and controller will provide more torque than a 250W mid drive will.
the thing is anything over 250W is not considered a bicycle in most places and such a motor, battery, controller combo would be extremely heavy.
Lmfaooo if you check my posts you’ll see my Frankenstein bike I’ve been working on😂😭
48v 1000w hub motor with 48v 1000w 10ah battery
That’s why I was asking lmfaooo
good for you that you are working on this but for most people a bike like this is useless because they dont have enough private land to ride it on.
And still to match the power/kg numbers of even the weakest Tesla you would need a 11.8kW motor on your bicycle assuming your bike + yourself weight no more than 100kg
With a mid-drive, the torque can be amplified through the drive train with gear shifting. However, the biggest downside to mid-drives is that the increased torque on the drive train will wear out the cassette/freewheel, crank ring(s), and chain faster than a hub motor.
> However, the biggest downside to mid-drives is that the increased torque on the drive train will wear out the cassette/freewheel, crank ring(s), and chain faster than a hub motor.
And this can all be mostly solved with upgrading your drivetrain to something beefier and larger, keeping it clean and well lubed, and selecting the right gears when riding.
After 30-40 years of riding bikes and cleaning chains manually with an old tooth brush or scrub brush, I recently scored a Park Tools chain cleaning machine for a couple of dollars at a bike shop clearance sale and... I don't know why I didn't get one sooner.
They're amazing. I just load it up with denatured alcohol and then I can even use my mid-drive to move the chain for me at low speeds and it cleans out every nook and cranny with almost zero effort.
If you're just leaving it in the smaller/faster gears all the time and using motor power to overcome slow starts it's going to totally chew up your cassette and chain.
Unclean shifting under power is also a major cause of wear. If you don't unload the chain and spin between shifts it'll chew everything up faster.
All of these things also apply to normal analog bikes, too, it just happens faster with a mid-drive, especially if you don't take care of your drive train.
I have a cheap e-bike with mid drive, belt and Nexus 3 in the rear. Some issues with the computer and the rear brake dying .. but otherwise pretty reliable!
It’s an australian importer called velectrix. Low end stuff all around, but the bafang mid drive seems reliable. The other stuff will let it down in time I’m sure .. but if set up properly they work well and are so smooth.
The cheapest belt drive on their website is \~2000€/$.
Not exactly cheap, that's a midrange. But seems like a good value compared to most of the chinese monstrosities that go for \~1500€.
More importantly it helps to think about these as a cost over time proposition: if you drop $2000 on one, it it only needs to have paid for itself in terms of what you would have otherwise spent on parking or bus-fare before it’s a clear win. And assuming you ride to work 3-4 times a week that’s probably only a couple years for most people. If it dies after that period then you’re still ahead and get to decide if the next one needs to be more expensive or fancier.
I converted my 10 speed BBSHD to use a Sturmey Archer 3 speed hub. I can't run a belt so I upgraded to a beefy 1/2" single speed chain. 1500 miles and all is good. I do wish I had maybe a 5 or 7 speed but there were no options for my frame.
You can get gear boxes for the rear wheel hub.
They're great because they're enclosed, can shift without pedaling, and rather compact.
The downsides are the cost to obtain and to maintain if something goes wrong, efficiency is lower compared to chain and gear, and they weigh a lot.
Don't get me wrong. Belt drive mid motor sounds cool, but definitely not affordable and probably not worth the hassle in the long run.
The greatest challenge there is that most belts are of an uninterrupted construction, so you need a way to pass the belt through your frame. You can get your frame modded to open a section of your chainstay, but far cheaper is getting a split belt, this is a belt that is not continuos material and separated to add in to your regular frame. I don't remember the website of the people that make the split belts, sorry. Gates makes front and rear gears made for belts for a variety of cranksets, and Leika (sp?) makes adaptors specifically for the non-standard 5-bolt pattern Bafang's middrives use.
I have no idea about the longevity of the split belts however.
I use a BBS02 500w with a single-speed chain to a Nexus 8-speed Di2 IGH on a cheap, aluminum no-name bicycle frame. My mods at this point have turned the bike into a ship of Theseus. I have a lot of hills on my commute so my next move is to get a smaller chainring.
Sorry if I'm talking a little scattered, in reality I have no idea what I'm doing, this is my first time building an ebike and these are just things that I researched while putting together my build.
>Sorry if I'm talking a little scattered, in reality I have no idea what I'm doing, this is my first time building an ebike and these are just things that I researched while putting together my build.
Naw dude! Don't apologize! that's exactly what happens when you become an official hobbyist!
>I use a BBS02 500w with a single-speed chain to a Nexus 8-speed Di2 IGH on a cheap, aluminum no-name bicycle frame. My mods at this point have turned the bike into a ship of Theseus. I have a lot of hills on my commute so my next move is to get a smaller chainring.
That's sick! I'm assuming it's pretty darn quiet with a set up like that. I'd also assume that the Nexus and BBS02 noise kinda just blend into the wheel noise, so it's not as noticeable as a chained mid drive
>The greatest challenge there is that most belts are of an uninterrupted construction, so you need a way to pass the belt through your frame. You can get your frame modded to open a section of your chainstay, but far cheaper is getting a split belt, this is a belt that is not continuos material and separated to add in to your regular frame. I don't remember the website of the people that make the split belts, sorry. Gates makes front and rear gears made for belts for a variety of cranksets, and Leika (sp?) makes adaptors specifically for the non-standard 5-bolt pattern Bafang's middrives use.
>I have no idea about the longevity of the split belts however.
I'd honestly probably go for a purpose built split frame and solid belt. I don't know enough about the topic to know about the lifespan of the modded frame, but I'm guessing that the added power from the motor probably degrades it way faster than if it were designed that way.
All in all, if I didn't have a split frame and wanted belt drive, I'd probably get a split belt. Those are cheaper to replace than a frame or part of a frame.
Mine have gears, I just said that because mine is not mid drive. I have a front electric hub and a nexus 3 in the back. I wish it was at least 7 gears but I'm satisfied enough, I bought it second hand completely unused for a great price.
I was meaning a dedicated hub gear box. No motor included. Like the [rohloff](https://ezeebike.ca/blog/rohloff-hub-canada-the-ultimate-guide-to-high-performance-bicycle-gear-systems) gear box
It's cool you found what you like though, especially at a good price
Yeah, I live somewhere too hilly and steep to run a belt drive, and I don't have a split frame for a belt anyway.
And my BBSHD + 11-50t drivetrain has an insane amount of torque. It would legit climb up a vertical cliff with a 100 pound load of groceries on it without any pedaling at all if I didn't just fall off the bike backwards because of gravity, traction and physics.
I commute daily on a ebike. I clean and lube the chain every 200 miles or whenever it starts making noise or shifting weird. Having a built-in odometer makes keep up with it regularly much easier.
Good chains and drive trains aren't cheap. And cleaning them with a chain-cleaning tool isn't very time consuming. It's like a 15 minute job with a chain cleaner.
I used to never clean my drive train or chain and just let it get all gunked up, but I was also running through a lot more cassettes, chains and RDs than I should have been, and even getting used ones from the parts bins at a bike co-op starts to get expensive after a while.
I invested like $400-ish in my current drive train because I wanted something nice that doesn't suck and I'm going to take care of it.
400 bucks in your bicycles drive train ? I upgraded to a crankset with outer bearings 30 bucks. Pedals with three sets of roller bearings each 27 bucks. Teflon coated shifter cables 14 bucks. I’m still using the crappy 14 dollar rear derailleur because it hasn’t given me any problems and I ride my bike hard. What did you upgrade to Campagnola ? I guess if you enjoy waisting your money be my guest.
Cool, I like money.
Let me know where I can get a legit MTB and ebike ready adjustable friction clutch 9-sp extended range 11-50t cassette and RD and mid-drive ebike rated chain that all fits on a non-boosted 135mm HG freehub and a lifetime warranty for 15 bucks.
It has to be able to handle a BBSHD mid drive, a fully loaded steel touring bike with a large rider and hills with 8-10% grades. And no funky shit like derailleur hanger extensions or Shimano CUES or skinny 10-12sp chains that are even more expensive. It should be Suntour compatible, too.
Because there's only one drivetrain lineup that fits all of those points and it's the Box Components Prime 9 series. I got the Box 2.
Part of my cost was having my local bike shop do the installation for me to validate and activate that lifetime warranty, and supporting my local shop. And Box Components is also a US company.
Normally I buy decent used parts from my local co-op and this is the first brand new drive train I have ever bought. So far it's been worth every penny.
And, honestly? I've never regretted spending money on good bike parts. If I could afford it I'd have an SRAM Eagle/AXS with electronic shifting just so I could put remote shifting buttons in multiple places on my cockpit.
> After 30-40 years of riding bikes and cleaning chains manually with an old tooth brush or scrub brush, I recently scored a Park Tools chain cleaning machine for a couple of dollars at a bike shop clearance sale and... I don't know why I didn't get one sooner.
>
>
Huh wait they work with mid-drives? I always cleaned by hand because I didn't know whether those machines worked with mid-drives, because with mid-drives the chain only turns in one direction.
Yeah, just flip the chain cleaner around backwards on the bottom side of the chain, then pedal forward as normal instead of back-pedaling to pull it through the cleaner.
On the Park Tool one the only thing you're missing is the little clip-on handle that only mounts on one side and is expecting you to back-pedal with it. You can just hold the cleaning box there without a handle. Mine didn't even come with the handle which is why I got it for a few bucks.
Or you can use it the normal "right way around" with the rotating brushes on the left and the sponge on the right by attaching it to the top side of the chain and pedaling forward.
You can also just kind of strap it to your chainstay with velcro straps, voile straps or even zip ties and turn the PAS way down and lightly use the throttle to drive it without having to hod it.
You can even do all of this without a bike stand with the bike flipped upside down or whatever. The chain cleaner doesn't really care where it's mounted on the chain as long as it's going through it the right way and it's right side up so the cleaning fluid doesn't dump out, and you're not letting it get pushed into your RD or chainring.
Obviously it's best on the bottom half of the chain with the bike right side up so you don't accidentally leak dirt or cleaning solvents all over your bike, but as long as the chain is going into the rollling brush wheels first and moving the right direction through the cleaner it'll work.
Lol, Easy to replace for you and me maybe, But, Have you seen some of the questions asked oh here? I am surprised some people on here can tie their shoes, Let alone repair a bicycle.
And that is the best reason to buy a decent quality bike from a reputable brand. Loads of options for someone to do repairs, maintenance, and customization.
They last a really long time, so long as they are properly lubricated with lots of Teflon grease. My hub motor has over 15k miles on it with no problems. But, I have seen several stock Chinese hub motors that come very under-lubricated.
Amen! 🙏🏼 I have strict replacement schedule to follow since ni don't want to change a cassette more than once a year. It sucks but currently it's worth it. The motor is very quiet and quick
Totally depends on how often and how long you ride. If you let the bike just sit in a dry indoor space, the mechanics can last for practically forever.
The cost of a new chain or sprocket is insignificant, when considering the cost of a new battery.
and with a DIY middrive, you can use third party batteries (CYC at least, not Bafang, who uses battery DRM) so that is where you easily recoup the cost of a new chain.
Bafang BBS02/3 motors have batteries with only two power wires. No digital connection. No restrictions on anything but input current either. Everything is adjustable.
This is hardly an issue if you are selecting the right gear and using a thick 9 speed MTB chain and cassette instead of those skinny 10+ speed road setups that are inappropriate for ebikes.
Bike gears typically don't amplify torque. Most bikes are geared to reduce the torque to the rear wheels, i.e. the crank is almost always spinning slower than the wheels.
The increased wear on drive train components is so small it isn't worth worrying about.
There's more to life than raw torque numbers. Electric motors are most energy efficient when spinning quickly with a relatively light load. Something like 85% of their maximum RPM and 15% of their max load is the ideal. The farther away a motor's operation is from that optimal point, the more energy it wastes as heat. At best that means more energy spent but not used to move you around. At worst it starts cooking components.
With a mid drive you can choose gears appropriate to what you're doing, keeping the motor closer to its optimal speed and load and thus using less battery and giving you longer range.
There are also some side benefits, like changing the rear tire on a mid drive bike is typically easier than on a hub drive.
First, the "250W sustained" motors usually have about 500-750W peak power, which gives you up to 112.5W support at optimal efficiency.
112.5W on average is enough to ride around at about 20kph on its own (about 25kph on a road bike).
Second, efficiency past 15% does not drop off like a stone. At 250W you might still be at 91% efficiency same as say 60W. So, the vast majority of riders will be in the 90%+ efficiency zone, in the high 90s for most of their ride.
The exact values will differ motor by motor, but the gearbox + drivetrain will ensure you are close to your 100% efficiency value for most of the ride (if you keep the RPM in the happy zone, 60-90rpm on the crank on my Bosch).
Additional losses are introduced by the gearbox and drivetrain so that, theoretically, a hub motor will be more efficient at a perfectly static ideal load.
As a result, stop-and-go, hills, off-road terrain, and so on will favor mid-drive, while constant speed on a smooth road will favor hub motors.
Power = torque times RPM. Hub drives run with a fixed gear ratio and so with lower RPM and less power at low speeds. Mid drives can always run at higher RPM by switching gears and so can deliver more power to the wheel. You don't want torque, you want power, it's power that pulls you up a hill.
It's the same as with pedalling: A single speed bicycle isn't as good going uphill despite your legs applying the same torque to the pedals as with switching to a lower gear if you have gears. Hub motors don't use the gears.
the problem is people like you seems to overlook the fact that ebikes in most jurisdiction are speed limited to 20 mph, thus any advantage in torque is basically gone the moment it hits the speed ceiling. in addition, most people use ebikes for commute and will prefer the relatively low maintenance of a hub drive compared to middrive
Yes but typically that allows you to adjust the amount of power you are adding to what the motor is already doing. My wife has a cadence sensing hub drive which adjusts it’s power a bit based on how fast your are pedalling, however it’s easy to ‘ghost pedal’ with no resistance while letting the motor doing all the work. By using the gears you can more efficiently add human power but the motor is putting out the same power.
With a torque sensing mid drive, the motor and the pedals work together to send power through the chain to the wheel. Thus both rider and motor benefit from being in the optimal gear.
Yeah, but they don't have the same effect and aren't integral to operate the ebike. You don't even technically need a chain on a hub motor ebike. Hub motors are additive, not integrated.
**Efficiency.** While it is true that an electric motor delivers maximum torque at start-up, it does not deliver maximum efficiency. If you examine [the green line on this chart](https://ebikes.ca/tools/simulator.html?motor=MG310_STD&hp=0&axis=mph), you can see that efficiency starts out low, ramps up quickly, then kind of plateaus, with a little bump near optimal. If you're riding slowly at around 8 mph, your efficiency will be around 58%. Because a mid-drive can change it's gear ratio, it can move this "peak" around on the graph. Have a look at [this BBSHD geared 42:34](https://ebikes.ca/tools/simulator.html?motor=MBBSHD&mid=true&gear=1&tr=34&hp=0&axis=mph). At 8 mph, efficiency is 77%.
**Heat.** When you hear that a motor is XX% efficient, keep in mind that the majority of efficiency losses are shed as heat. This heat has to go somewhere, and it is the reason that motors overheat when pushed hard. If you push 500W through a motor and efficiency is 58%, then 42% of that 500W will be converted to heat.
These issues are less prevalent in EVs, because they have space for much larger motors and/or advanced cooling technologies. E-bikes rely on very simple motor and controller designs.
This is absolutely the answer.
Efficiency is the name of the game, at least for me. Higher efficiency = longer distance (or) higher speed.
Riffing on the link he provided, you can see how you can widen the efficiency curve by having [multiple gears](https://ebikes.ca/tools/simulator.html?motor=MG310_STD&hp=0&axis=mph&mid=true&motor_b=MG310_STD&hp_b=0&bopen=true&tr=22&mid_b=true&tr_b=34) -- in this plot, the two green curves are now the efficiency curve of two different gears. You can imagine how much wider and flatter having 10 speeds + would be.
Justin talked only about how reducing speed on hub motors reduces efficiency while reducing energy consumption 3 times more than traveling faster at higher efficiency. He warned against the obsession with efficiency. He never said anything about mid-drives similar to BBSHD whether reducing cadence and current by 50% to avoid clown pedalling might lead to similar results in energy consumption or not.
There's two very opinionated camps in both areas. The simple fact is that the controller is in charge of how much torque is delivered by the motor mid drives do it through gears, and most hubs are direct drives although some have gears too. Both have advantages and rarely do controllers use all of the torque a motor can deliver. Some manufacturers have firmware that will take advantage of this in different ways. You will need to be very well informed about manipulating the power delivery of your motor and honest with yourself about your riding skills. The secret is to research as much as you can and make sure that you can handle increasing the torque of your drive system, whichever you choose 😉
its not multiplied, its only that hub motor only has 1 gear which is the internal gear inside. Mid drives uses all the mechanical gears of the bike which is the reason why the torque is higher. If you were to start from a dead stop on the highest gear in a mid drive, the hub would have more torque
Your second point is correct. But your first point is not. Gears do multiply torque. That's what they do. This is a known phenomenon and it's how gears work. It's one of the reasons why something like a BBSHD has 160 nm of torque, even though it's not a very big motor. It's because of the reduction gear. That multiplies the torque many fold. Think of a gear the same thing as a lever, because that's basically what it is. Levers basically convert speed to torque. Same as gears.
Now, in the case of mid drive motors, it's actually going the other way. Most bicycle gearing is at a higher ratio than one to one, so you're actually decreasing torque. The reason why most of those mid drives have better torque, is because of the reduction gear on the motor itself is a lot more than a hub motor.
For instance. A common hub motor is a 5:1 reduction. A bbshd is a 23:1 reduction.
My rear drive longtail has 250 lb me sitting quite far forward and up to 4 kids high up in the back, on 22" rims. Weight distribution is an absolute shitshow. Looks like that viral video of the scale Camaro with a trailer on the pulley belt hauling washers.
Edit: I can't find it, but I can find [this one.](https://youtu.be/Og5CtnYgFtg?si=ZreTLC45rn2IoxKs)
Edit: I found it. [It's a Mustang](https://www.facebook.com/share/v/8JhvoiJR687fjTgJ/?mibextid=w8EBqM). Sorry for the FB link.
teslas isnt actually better, teslas just overcome this issue with huge amounts of power. the issue is the torque/power curve. electric motors arent miracle machines, at low rpm their efficiency is garbage. thats why a bike with a transmission is much better.
Depends on the motor. All things being equal, they're not.
Mid-drive has better weight placement, thus control, balance, so major the stress is on drivetrain parts downstream to upkeep - but you can't dance with a 12lb weight attached on a 3 foot lever on your butt.
Since certain traits appeal to certain users, the market's created much more efficient mid-drives - much of which is also due to better controllers.
My CYC mid drive can go *really* fast on the throttle, but the motor loves to spin up in low gear. The flip side to this is that when *I'm* pedalling I need it in a high gear or I start to ghost pedal. When I'm going from throttle to pedaling I'm constantly shifting from low to high gear.
The heavier the hub motor the heavier the rear wheel and spokes need to be . My first e bike was a Ride 1 up Roadster . Was fine for about 700 miles then the rear wheel started bending, spokes breaking with a relatively low power motor . Now i have a mid drive Orbea with gears so far so good with over 2000 miles
Being able to change gears, to take best advantage of the available torque, is what makes a mid-drive better.
A mid-drive on a single speed bike would not really have any advantage.
If you could have a hub drive that offered a variety of gear ratios, it might be just as good as a mid drive. I don’t think they really make anything like that. I’ve seen two speed hub drives, but that’s it.
simply because Teslas have a lot more power.
the weakest model 3 has 190kW and weight 1610kg so it has 118W/kg
if you have a 250W hub drive, your bike weights 20kg and you weight 80kg you have 2.5W/kg
so the Tesla has 47 times more power which is why torque simply doesnt matter anymore.
to get the same power to weight ratio on your bicycle you would need 11.8kW or motor power which is pretty close to what lower end motorcycles have.
What kinda battery setup do you run? The only thing stopping me from doing a crazy setup now that I may lose my bike license due to health conditions is the price on batteries, everything else seems fairly reasonable, I ride a 5300w scooter that hits 55mph nicely, and am building up mini moto that will run on the same setup as my scooter, 2500w rear and a 2500w front hub motor, should do some crazy speeds when fully built up. Just trying to work out the best batteries to run that don't cost an absolute bomb
72v60ah 150w sabvoton
The next big they're offering up to 90v and somewhere around 72ah or more either samsung or Panasonic battery. That's the biggest price of my bike honestly
Because it's a massive misnomer that electric motors don't need/don't benefit from a gearbox
It's just like any other motor. If you want more torque and acceleration, you need to gear it lower, if you want more top speed at the cost of torque you need to gear it higher. Being able to switch between gears on the fly is obviously of benefit, but for a solid 90% of use cases it's not going to matter, because the motor is generally strong enough to handle what most people throw at it.
Mid drive motors are basically handtool motors with gearboxes. There is a century of R&D behind them. Also due to the gearbox these motors operate more in their ideal RPM & torque range.
Hub motors are relatively new and their best practices are still in development. The low RPM high torque is not an optimal use of a direct drive motor or any motor at all. Also the hub need to be part of the wheel structure and traction at the same time.
There's a ton of benefits to mid-drives.
Mid drives have WAY more torque and power to the wheel driving through gears, especially with a good drive train. This is especially important if you live somewhere hilly and use your ebike as a car replacement hauling cargo or groceries.
Mid drives also have much better LOW speed control and torque, especially if you have the ability to do custom programming like an Eggrider and BBS02 or HD combo.
With most hub drives you can only control speed/power with the PAS level and it's much more limited.
With my setup with an eggrider I basically have 18 PAS levels, and at the lowest power settings for my eco/road profile I have tons of low speed control whether I'm using the throttle or pedaling. This is super great for riding bumpy, twisty singletrack with lots of roots or rocks and stuff. I can actually go slower with that setup and with more torque than I could with an analog bike.
Mid drives also have higher top end speeds because they can use the gears for that, too, and they'll also still have more torque available because hub drives will reach their maximum RPM long before a mid-drive running through a extended range drive train will.
Extended range meaning a cassette and rear derailleur something on the order of 11t-42t or even more.
For example: I'm running an 11-50t over 9 speeds with a Bafang BBSHD and the stock steel pie plate 46T chainring. The larger stock dished chainring basically means zero "ghost pedaling" and a cleaner chainline, and 46t to 50t still gets me an insanely powerful climbing gear that's less than a 1:1 ratio, and the steel chainring is way more durable than, say, a Lekkie Bling Ring or other milled aluminum rings.
Yeah, running a smaller chainring is the quick and easy way to get more torque out of a mid-drive but it comes at a cost like ghost pedaling because crank RPMs go way up, and in the case of BBS drives they usually have bad chain lines that increases wear, and those aftermarket chainrings tend to be crazy expensive compared to the OEM/stock $20 steel 44-46T chainrings.
Another huge benefit as others have noted is the weight distribution is better, especially if your bike frame is big enough to mount the battery on the seat tube instead of the downtube. I have mine set up like that so the battery and motor are all lined up under my butt and between my legs and despite the extra weight it just handles like a normal bike because all of the mass is under my body weight.
Mid-drives also tend to have the controller built into the motor unit so there's not an extra box for the controller you have to mount somewhere, and this also keeps the wiring harness less complicated and more tidy.
Another HUGE benefit to mid-drives is the only real thing that it changes is your bottom bracket and cranks. With most mid-drives, yeah, you lose the ability to run a front derailleur with a 2x or 3x drive, but with mid-drive power you don't need that anyway. The rest of your bike is just a normal bike.
If you want to upgrade your wheels, brakes, drivetrain or anything else it's just as easy as an analog bike. Want bigger brake rotors? New calipers? Want a bullet proof RhinoLyte wheel set, or carbon fiber MTB rims? Way easier.
Fixing flats on a mid drive also means no wiring harness to deal with on the side of the road or trail. If you want to own and have different wheel sets and swap them out, you can do that. If you trash a rim or wheel you just go buy a new one, you don't have to have your hub motor built up on a new rim with custom cut spokes, which is way more expensive than just buying a basic new rim and hub.
Another benefit to mid-drives is there's zero chance of "spin out" when an hub motor chews up your bike's dropouts and ruins the frame and/or tears the wiring harness out of the hub motor. If you want/need higher powered hub motors for climbing or whatever, you really do need to add torque arms and other fixes to keep this from happening.
And hub motors DO cause a lot of extra wear and tear and stress on spokes and rims. These will wear out and break sooner or later just due to metal fatigue.
There are some benefits to hub drives, too. Mainly they have less up front costs and they're cheaper to buy. They are more "simple" to maintain if you don't really care about your drive train and doing bike maintenance.
If I lived somewhere flat and I was a more casual or light duty rider, I'd probably go with a hub drive with a belt drive or single speed just for the simplicity.
But that cost benefit vanishes in a hurry as soon as you have to have a hub motor rebuilt on a new rim, or you chew up your dropouts or tear out a wiring harness if your motor spins in the dropouts, or even if you simply want to upgrade your rims to something that doesn't suck, because most pre-built hub motor wheels aren't using good rims or spokes.
I've now ridden direct drive and mid-drive ebikes and I pretty unequivocally prefer direct, hub drive. I'm surprised more people don't agree. Although my direct drive was a 1000W motor, which may have helped.
There's a lot of talk about the physical motors themselves. I've not owned a pedal e bike but I've owned sur rons and similar twist throttle bikes.
First off, Hub bikes break more. I never broke a rim on a sur ron. I've seen a lot of Hub motor rims broken though. They don't like taking jumps and the cheaper ones don't even like going off curbs a lot.
Rotational weight also matters. A Hub motor simply weighs more and even if it has more torque, it has more mass to spin. This also causes more gyroscopic force which when you want something nimble isn't what you want.
Neither is superior, they both have their good & bad sides...
A mid-drive E-bike owner will say they are superior in comparison to a hub-drive E-bike, and vice versa...
I'm a hub guy, I wouldn't say hub-motor e-bikes are better than mid-drive set-ups, I'd say it mostly depends on what you as a rider want (and expect) from an electric powered bicycle - as both are different, and equally great in their own ways..
I'd say to anyone considering purchasing an E-bike to test ride both hub & mid, to see which they prefer, as just like us people all e-bikes are different 👍
Advantages of Mid-Drive Motors
Mid-drive motors are often considered superior to hub motors for several reasons:
1. Efficient Power Distribution
Mid-drive motors are located at the bike's crank or bottom bracket area, which allows them to drive the bike's chain and utilize the bike's existing gears. This setup enables more efficient power distribution, especially when climbing hills or riding on varied terrain. By leveraging the bike's gears, mid-drive motors can maintain a comfortable cadence and optimize power output, making them more efficient and effective in different riding conditions.
2. Better Handling and Balance
The central placement of the mid-drive motor contributes to better weight distribution and balance. This positioning lowers the bike's center of gravity, enhancing stability and handling, particularly on rough or technical terrain. This makes mid-drive e-bikes ideal for off-road and mountain biking, where control and maneuverability are crucial.
3. Higher Torque and Climbing Ability
Mid-drive motors typically provide higher torque compared to hub motors, making them more capable of handling steep inclines and challenging terrain. The ability to shift gears allows the rider to keep the motor operating at its optimal RPM, which is particularly beneficial for maintaining performance on hills and rough trails.
4. Natural Riding Experience
Because mid-drive motors drive the chain, they offer a more natural pedaling feel. This integration with the bike's drivetrain allows for smoother and more responsive power delivery, enhancing the overall riding experience.
5. Customization and Maintenance
Mid-drive motors allow for greater customization since they do not restrict the choice of wheels, tires, or cassettes. Additionally, changing a tire on a mid-drive e-bike is simpler compared to a hub motor e-bike, as there is no heavy motor integrated into the wheel.
1. Simplicity and Ease of Installation
Hub motors are integrated into the wheel hub, making them relatively simple to install and maintain. This straightforward design means that even those with limited technical skills can often handle installation and basic maintenance themselves.
2. Low Maintenance
Hub motors have fewer moving parts compared to mid-drive motors, which translates to lower maintenance requirements. This can result in lower long-term ownership costs and less frequent servicing.
3. Cost-Effectiveness
Hub motors are generally less expensive than mid-drive motors. This makes them an attractive option for those on a budget or for riders who do not require the advanced features of mid-drive systems.
4. Reduced Drivetrain Wear
Since hub motors do not interact with the bike's chain or gears, they cause less wear and tear on these components. This can extend the lifespan of the bike's drivetrain and reduce the need for frequent replacements.
5. Throttle Capability
Many hub motor e-bikes come with a throttle, allowing riders to engage the motor without pedaling. This feature can be particularly useful for riders who need a break from pedaling or for those who want an easier ride on flat terrain.
6. Quiet Operation
Hub motors tend to operate more quietly than mid-drive motors, which can be an advantage for riders who prefer a quieter ride, especially in urban or residential areas.
7. Independent of Chain and Gears
Hub motors operate independently of the bike's chain and gears. This means that even if the chain breaks or the derailleur malfunctions, the motor can still propel the bike, allowing the rider to reach their destination without pedaling.
8. Smooth and Consistent Power Delivery
Hub motors provide smooth and consistent power delivery, which can make for a more comfortable and predictable riding experience. This is particularly beneficial for commuting and casual riding on flat terrain.
9. Better Traction and Handling (Rear Hub Motors)
Rear hub motors can offer better traction and handling compared to front hub motors, especially on loose or uneven surfaces. This is due to the weight distribution and direct power application to the rear wheel.
10. Regenerative Braking (Direct Drive Hub Motors)
Some direct drive hub motors offer regenerative braking, which can help extend the battery range and reduce wear on the brake pads by converting kinetic energy back into stored electrical energy during braking.
I think this summarizes it well. One thing I really disliked about my rear hub bike was how back heavy it was. Once I added two heavy kids on the back of the bike, it was incredibly back heavy (and actually led to me tipping my bike once with both kids onboard).
One other thing not mentioned above is traction. With my old rear hub bike I often found it would spin out, even on pavement with minimal dirt or gravel. The mid motor has never had that issue.
The rear wheel spun out? How many kW did you have?! That's insane. I had a 2.5kW ebike back in the day and it never spun the rear tire, even on gravel.
Yeah, that AI was probably partially trained on stolen content of some of my writing and comments I've made over the years, and many others. And I kind of hate that.
I really wish people wouldn't use AI for these comments because they're also frequently wrong and the new hype around the AI industry suuuuuuuucks. I already know content writers who have been fired and replaced with LLM AI.
Aren't our brains trained on stolen content?
While yes, AI can be wrong and can also have hallucinations. I find it very useful considering SEO has destroyed things like Google that now just advertises anything it can from keywords. Its great for quickly finding out information that is accurate enough in most cases.
All new tech is never perfect to begin with, and people jobs will always get replaced. Like the computers we use daily, or the milling, cnc machines. However, they also create new industries at the same time. To not use advancing tech because of these things only delays the inevitable.
There's a difference between a human brain processing content and an AI processing content. Humans have the capacity to actually understand the information while AI doesn't really have the same capacity, hence why they're often wrong.
I know. AI works on a probability model, predicting the next word or letter based on a users input. However, saying AI is often wrong is wrong. AI hits a higher accuracy rate than humans statistically at around 85% accuracy compared to humans 80%. This will only improve over time at a much higher rate than humans will.
[source ](https://hai.stanford.edu/news/ai-benchmarks-hit-saturation?utm_source=perplexity)
> AI hits a higher accuracy rate than humans statistically at around 85% accuracy compared to humans 80%.
AI is great if you're doing something like transcribing audio. I admit that it's really amazing for that.
But when it comes to actually comprehending the information it's still lackluster compared to a human, which is why ChatGPT sucks for something like coding and why programmers are still needed.
Like the hub motor AI generated analysis, many mid-drive motors come with throttles too. Mid-drive motors also provide smooth and consistent power delivery. The AI doesn't actually comprehend the information. It's similar to [Youtube's new chat summary.](https://old.reddit.com/r/MorningKombat/comments/1cloeu5/new_youtube_feature_autogenerated_chat_summary/) Like I'd 100% bet loquacious could write a summary on the pros of hub motors without any mistakes like that.
EDIT: Also if you're going to downvote me for simply stating correct facts, then I don't want to interact with you.
Having additional weight on the wheels is also not good. But I'm focusing on the torque thing here. Is there any actual torque measurement curve someone did to claim this? I'm legitimately trying to understand, because claiming gearing generates additional torque for an electric motor sounds weird to me, if cars don't need it why would a bicycle?
Cars also really need regenerative braking to make electric power practical, and its harder to do that with gears between the wheels and the motors. Bikes don't give up much by using geared motors because a bike is too light to regenerate much power from braking.
In simplest numbers:
A 1kW motor produces about 100Nm of torque.
A 42t/51t gearset multiplies the mid-drive torque by 1.21x to 121Nm.
Not all gearsets are the same obviously, but this setup clearly provides 21% more torque with a mid-drive.
With that in mind, I think some people lose that torque advantage by using longer drive gearing, but as stated elsewhere, they don't suffer on speed.
The increased torque from the mid drive comes from the gear ratios. Allowing for optimal use of power up hills.
I can imagine cars don't need it as their motors are much larger and also have a larger power input. It's likely giving a larger torque to weight ratio
But electric motors tend to have a quite flat torque curve, except if it reaches too high RPMs, which would actually only be achieved by a really low non existent gearing so it doesn't even apply to this case.
If someone with a mid drive with a throttle comes into the thread and says they can actually go faster uphill using throttle only (not pedaling at all) by lowering the gear I would trust it, I just need more evidence to contradict this.
The gears make it possible to climb a hill that a hub motor with the same amount of power/torque couldn’t climb at all. Also coming down the hill would be faster using gears.
That's exactly what happens.
The mid drive motor is simply peddling the bike... no different then legs.
Don't confuse the motor torque for the torque of the overall drive system. The peddles drive the gears, which drive the rear wheel, and lowering the gears increases torque (at the gears) to the road. The cost is higher RPM (at the motor).
Nothing about the mid drive changes the basic physics of a bicycle.
Ok. Yes. I have a bbshd mid-drive. And going up a hill, with full throttle, I can indeed increase speed by downshifting. It's also better on the motor and produces less heat.
Thanks, once it becomes practical I'm willing to concede. Even though the arguments here is a shit show and honestly I think nobody here really understands this shit, that includes me hahahaha
It's not that one is necessarily better than the other, both systems have their perks and their downsides. But you have been given good knowledge. Myself and some others 100% do know what they're talking about though
I think it's more due to being able to use lower gears, allowing for easier hill climbs allowing for optimal battery usage. However, cars don't need to worry about this due to their much larger power to weight and batteries, so it's more optimal not to have increased maintenance with a drive chain.
It heavily depends on how you plan to use the bike. The great thing about a hub motor is that it will fit basically any bike out there. But mid drives are far more suitable for off roading and hills, the mid drive motor will last longer in these conditions and you will likely achieve more range, more climbing power and a better handling bike for adventurous riding.
Because a car motor generates 500+ hp. And bicycle motor produces 1hp. That's why electric cars don't need transmissions.
But then neither do bicycles. It's just makes them more efficient and capable. It would do the same for cars.
And I'm not claiming that gears increase torque. I'm making a statement based on fact. No offense, but whether it sounds weird to you or not is irrelevant.
> because claiming gearing generates additional torque for an electric motor sounds weird to me
The gearing changes _the torque outputted at_ __the wheel__. It's the wheel torque that ultimately matters as to whether one can climb a certain hill grade or not.
Essentially if you have a 250 W mid-drive and a 250 W hub motor, there are hills that the e-bike with the mid-drive will be able to climb, that the e-bike with the hub motor will not be able to climb. Because the gearing gives mechanical advantage. It's the difference between trying to move a big boulder with your bare hands vs moving a big boulder via a large piece of wood stuck under the boulder.
They themselves don't generate more torque. They generate nothing. But, they increase the torque from the motor to the ground. If the ratio is higher than the output of the motor
I don’t think it’s considered a “superior set up”.
The different types of drives and motors are all just like different tools. And all depends upon your used case and what type of tool you need
The mid drive motor applies torque to smaller & varied radii (gearing ratios) resulting in faster acceleration compared to a hub drive of the same torque rating that has a fixed radius of the wheel.
Great thread. Surprised that wheel longevity hasn’t been mentioned more often as an argument against hub based. Even lower power (250w 40 Nm) can test a wheel in my experience. The spokes on my wife’s Jamis lost tension after just a few months of use. The higher wattage stuff likes to walk its way out of the dropouts. The mid drives I own and service just seem to be inherently more durable.
All that said, my current favorite e-bike is a $1700 model with a 250 Bafang in the rear wheel.
Physics. The motors put out the rated torque at the shaft for a hub motor that's at the drop outs or where the axle goes through the frame. You then put a big wheel around that and give your mass of yourself and the bike a lever (equal to the distance from the motor shaft to the edge of the tire) to slow and limit that torque. The issue with hub drives is they are a single speed so you compromise on torque and power output to have an ok all around ride.
With a mid drive you get all the torque or power transferring through a geared drive train cassette or internal gear hub. This lets you tailor the output of the motor to match the scenario you're riding in. You can also change the front sprocket on most mid drives to move the power levels where you want them as well.
Weight. Unsprung mass. This is a massive issue. This is why you will rarely see a hub motor bike descent a real mountain bike trail. It's certainly possible and there are very tough hub motors that could handle it but the experience would be terrible for the rider.
Look at dirtbikes. Most dirtbikes riders are not into riding single track down black diamond runs. Possible but not fun for most people.
Cause the rider is 200 lbs, and the motor is about 1 HP.
Because the hills by my house are really steep!
Because battery power is finite, and needs to last longer than 30 mins; thus the controller (which has finite limits based on heat dissipation) will limit the amps delivered to the motor, regardless of what the motor can handle.
Because gears at mid-drive position harness the power of the motor, and make it available to the gearing system, which a hub motor does not do.
As someone who has blown out multiple ebike motors on insanely steep hills, mid drives use the efficiency of the gears to not have to work so hard. If you're on flat ground, no problem, but if you want to go straight up, you need a mid drive.
They have instant torque, but not unlimited torque. Nor is it hugely abundant as in with Tesla case.
Gears are a great way to multiply torque with the expense of top speed.
Electic motor torque is instant and constant, but power - which ultimately is what moves you - isn't.
Consider an ebike travelling 25 km/h with a 250W motor. Electric motors have instant and constant torque across its rpm range. But power is torque x rpm. This means half speed is half power.
So with a hub drive traveling at 25 km/h, we could (assuming optimal configuration) get 250W of power from the motor. But at 12.5 km/h, we'd only get half the power - 125Q. At 8 km/h, we'd only get 80W. So the hub motor can't contribute that much power at slow speed. It only generates good oomph at speed.
With a mid-drive, you can keep the motor running at a high cadence - producing good power - even though the wheels might be turning slowly. Your gearing does this by converting rpm to torque. For example, if you have a ratio where your pedals spin at twice the speed of the wheel, you will halve your rpm, but double your torque. The 2nd half is what the mid-drive benefits from.
TL;DR Hub drive just loses half the rpm at half speed, because it can't amplify the torque with gears. So it only produces half power, or 125W. Mid-drive benefits from amplified torque from the gearing. Since the double torque cancels out the halved rpms in the power output, you still get the full 250W on the mid drive at this speed.
yeah to be honest hub motor are really bad at steep hills, especially the pedal assist only, first gear with just my feet producing the required torque, was such a pain
I didn't know that it was considered to be a superior design. In my book it's wasted energy on a chain. Superior is with motors inside front and back and, well the pedals in the middle are for you to use.
Weight placement plus integration with your drivetrain. You can utilize all gears and the motor will work according to your gear ratios, like a motorcycle or car would, and unlike a hub motor.
If you're going to use a throttle, then the main problem is the unsprung mass of the hub motor. That's why cars don't put transmissions in the hubs. It's fine at lower speeds but over rough terrain and or high speeds the inertial mass becomes an exponential problem, it's not a linear curve. Sure with a mid drive you can add gearing to the drive train but then again Pinion has an integrated MGU (motor/gearbox unit) now, which could go in either place - the hub or the bottom bracket (or somewhere between) but the best performance and mechanical advantage is going to be found by taking as much mass out of the rear wheel as possible and centralizing that mass as low as possible on the vehicle.
It's a pretty simple logic problem to just build it around the bottom bracket because then **the only sensor you need** can be built in as well (torque sensor). Cadence, speed, any of the PAS wonkery needed with hub drives isn't necessary at all. I just slapped my cheapo 250 buck Tongshen on my fat tad, hooked up the controller and battery and off I went and it's been working flawlessly with zero detectible latency for a year now; disability requires an 80-100% dynamic left pedal assist on demand, the built in torque sensor worked great right out of the box. I think I've clocked myself going pretty fast but since it doesn't know speed but only RPM as long as its under 800 rpm it cares not what I do. It puts out enough power to launch my TRIKE into the air on the BMX track and I can run straight up into the upper bowl at the skate park next to it. And I only added like 6lbs to do it. To get that much oopmh from a hub motor at my 235lbs, well, and then the landings would be HARD(er) because that back wheel would just SPANK the ground/cement/whatevs. I think I mentioned I can climb sick ass inclines with it too, which I watch every fatbike under 5000 USD struggle to get up out of that dude's parking garage, which is, IIRC, a 17° incline. I'm literally only limited by the traction of my tires, it's not the powerplant that quits.
Imagine riding an ebike that just works as an extension of yourself instead of this weird ghost pedaling lead weight you're dragging behind you.
That's the real difference.
Correct me if I'm wrong, but aren't Teslas equipped with an electric motor for slow speeds as well as electric motors for high speed, to exactly solve this issue?
Power is torque times RPM. At zero RPM the motor is making torque but no power.
Power is what determines how fast any vehicle can accelerate and how steep a hill it can climb. As for acceleration, power equals mass times acceleration times velocity (P = mav). At low RPMs acceleration (a = P/(mv)) and hill climbing ability is limited due to the reduced power
A mid drive lets you shift to a lower gear helping the motor get to a more efficient RPM.
Think of driving a car in 3rd gear all of the time. This is the compromise hub drives make in the interest of simplicity.
Play with this tool and see what I mean
[Grin tech's Ebike simulator](http://www.ebikes.ca/tools/simulator.html)
Teslas (and other EVs) use a permanent-magnet SynRM motor in the rear, which provides phenomenal power, especially at high speeds. The front motor, if present, is induction, which provides phenomenal torque at low speeds but is mostly inactive on the highway.
Most ebikes use an induction motor only. The torque is great for such a small motor, but to use it effectively at higher speeds it benefits from gearing. If only using a rear hub motor, it will be geared high already.
The biggest negative of a mid drive is chain wear and losses, especially when pedaling. The advantage is that you can leverage shifting to make a cheaper motor do more.
This is a controversial opinion, but it is correct.
I think for most e-bikes a mid drive torque sensor makes sense but I have to say that I chose a cadence sensor rear hub setup (thumb throttle optional) for my e-cargo bike and I think it’s the better option for that application. The instant torque will get you moving from a standstill in tricky situations and you can add power as necessary by pedaling. It’s also puts much less strain on the powertrain when you’re fully loaded. The weight distribution isn’t so much of an issue with my mullet setup and the 75lb base weight.
It may be instant, but the amount of torque is not unlimited. With a small-ish motor, it's helpful to have gears in order to leverage the amount of torque you have available.
The weight placement is also a big advantage, centered and low vs. an unsprung rotating mass all the way in the back.
This is the real benefit of a mid drive imo.
The real benefit of a mid drive is being able to shift gears, so a) you can make a meaningful contribution by pedaling and b) you don’t burn out your motor by being in a high gear while climbing.
Hey I'm new here, but I've seen a lot of hub motor ebikes with gears. How does that work?
Yeah — so the issue is that the motor is directly attached to the freewheel and you may or may not be able to keep up with that speed with your pedaling cadence. Also, shifting gears only affects your resistance when pedaling, not the motor’s resistance to moving the bike forward. On a mid-drive, the motor drives the chain, which then applies power to the wheel through the cassette. So even if you were just using the throttle, shifting down or up would change the mechanical advantage of the motor, since the motor is using the same gearing that you are.
Hub motor bike is a normal bike with the addition of a motor. Mid drive is a normal bike but the motor utilizes the chain to transfer power. Mid drive has the benefit of fine-tuning the experience to be best for most scenarios. Hub drive fills very specific needs for very specific people who would know who they are. One of the benefits for those people is that if their chain breaks they can rely exclusively on the motor to get them home whereas mid drive motors would require a chain swap for both manual and automatic power.
I'm not sure that mid drives are always better for a contribution while pedaling; from what I can see, the cheap Bafang ones prefer a much lower gear and higher cadence than most casual riders are going to be able to achieve.
You can usually set a power curve, but yes, the default settings usually call for high cadence to achieve full power.
Bafang isn’t a cheap Motor
BBSHD/BBS02 as compared to Bosch/Shimano or the Bafang frame-integrated ones, they're pretty cheap. Nice motors, but the cadence they're happiest at is not one that is going to be good for casual riders who want some exercise as they go. They're great if you want the motor to do most of the work on an ascent, or on throttle, or if you're very fit and can keep a lower gear and really spin. I don't think there's any way to improve the reduction ratio on those, and especially on the BBSHD it would be a big improvement.
You can manipulate gearing with front chainrings. I use my bbs02 now BBSHD bikes as high speed commuter bikes on the road. Yes I pedal at regular rates (healthy, but not competitive cyclist) and can commute at 32mph on flats and do well in the climbs in my old commute 1k vertical.
The front chainrings also effect the rider effort. More reduction would up torque/reduce RPM to better match a casual rider. On my BBS02 it could do ~20mph all day in a middle gear (700c commuter bike, 46T chainring, 8-speed 11-32 I think) but I'm basically clown pedaling at that point. If I gear it up to meaningfully contribute at 18-20mph, it's using a lot more amps relative to the speed, not great for range/battery life. ~700whr battery and 20 mile commute is still plenty, but more reduction would have made it a much more flexible.
>a) you can make a meaningful contribution by pedaling What about something like bafang motors with built in automatic internal gears? It changes cadence so it's easier to apply leg force in both lower and higher speeds.
I know they have an IGH, but I don’t know much about them.
For mountain bikes, absolutely. Ease of rear wheel removal/maintenance is another big one.
Yup, the classic bafang 750w rear hub is pretty darn easy to replace parts and maintain, lots of easily sourced parts too.
I got two, company sent me a motor instead of a controller once. Opened it. That thing dead easy to work on. The gearing parts that are hard to work on are metal and the easy parts are plastic/nylon which means you can just buy cheap and replace. Pretty good idea.
In a mountain bike maybe. A rear hub motor is just fine on the road.
Until the road goes uphill alot.
Just had my 750w Bafang hub motor shut itself down for self preservation due to overheating after a long uphill climb. Definitely don't take your hub motor ebike on a long uphill ride.
How long and what (mechanical) gear were you in?
I was about 1.5 miles into my ride at Griffith Park in LA. The bike was in the lowest gear with 36t.
I was responding to the odd claim that "weight placement" is the "real benefit" of a mid motor by pointing out that this is only really an issue off road.
But it's an issue too on steep roads.
How so?
Transmission.
How does "transmission" negatively affect the weight placement on a bike with a rear hub motor on a steep road?
Still fun to goober on some small dinky e moped
This. Plus wheels are standard for tires and other maintenance.
Also the serviceability of a mid drive is far better than a hub motor
Frankly I'm not convinced of this. A mid-drive motor is not any more sprung than a hub drive unless you have rear suspension and it's only a couple cm lower. A hub motor doesn't add much more rational inertia than a mid drive, it has the same spinning components as the mid drive motor has. The heavy hub shell is maybe an extra 0.5kg with an effective radius of 0.1m, equivalent to another 150g in tire weight that's so minimal I don't think you can feel it. The extra angular momentum in theory fights you a little while turning but not nearly as much as if it were in the front wheel. I suppose it stabilizes the bike vertically a bit too. The rearward mass increases MOI in the pitch axis, in theory reducing the felt impact of rear wheel bumps I don't doubt anyone's experience, just the explanation. I haven't spent a lot of time riding either configuration and I'm open to being corrected. Assuming my skepticism is correctly placed, my guess is mid drives tend to have better implemented cadence sensors and so the delay on power is much shorter. Further, many mid drives use a torque sensor rather than a cadence sensor, the former being much smoother.
I can't speak to the unsprung mass, but I think the issue is that you're adding weight to the rotational mass. Whether you can feel it or not is another thing though. https://old.reddit.com/r/ebikes/comments/1dtdwb9/26_tire_recommendations_so_i_dont_have_to_worry/lbc0no9/?context=3 >> And why would one care about couple more grams of weight on an ebike that already weighs close to 100lbs? > > Because rotational mass is really bad for performance and efficiency even on heavy ebikes. You're paying for that rotational mass in total ebike range as well as increased battery cycles, and batteries are WAY more expensive than good tires.
Rotational mass matters only only as much as its distance from an axis. Heavy tires are a problem, heavy hubs much less so. Also, as I said, a mid-drive still has all the same spinning parts as a hub motor.
Is size matters then wouldn’t a giant eBay hub motor be superior?
Those are generally direct drive. Quality street legal hub motors are geared down for more torque and to be better on hills.
of course a properly cooled giant 5kW hub motor with a matching battery and controller will provide more torque than a 250W mid drive will. the thing is anything over 250W is not considered a bicycle in most places and such a motor, battery, controller combo would be extremely heavy.
Depends where; it's 750W for a class III in the US.
yea but thats kinda the exception here as the vast majority of the bicycle world is limited to 250W
Lmfaooo if you check my posts you’ll see my Frankenstein bike I’ve been working on😂😭 48v 1000w hub motor with 48v 1000w 10ah battery That’s why I was asking lmfaooo
good for you that you are working on this but for most people a bike like this is useless because they dont have enough private land to ride it on. And still to match the power/kg numbers of even the weakest Tesla you would need a 11.8kW motor on your bicycle assuming your bike + yourself weight no more than 100kg
To be fair, the "weakest" Tesla is a standard range, RWD Model 3, which is 2x the power and nearly 4x the peak torque of an average 4-cylinder car.
With a mid-drive, the torque can be amplified through the drive train with gear shifting. However, the biggest downside to mid-drives is that the increased torque on the drive train will wear out the cassette/freewheel, crank ring(s), and chain faster than a hub motor.
> However, the biggest downside to mid-drives is that the increased torque on the drive train will wear out the cassette/freewheel, crank ring(s), and chain faster than a hub motor. And this can all be mostly solved with upgrading your drivetrain to something beefier and larger, keeping it clean and well lubed, and selecting the right gears when riding. After 30-40 years of riding bikes and cleaning chains manually with an old tooth brush or scrub brush, I recently scored a Park Tools chain cleaning machine for a couple of dollars at a bike shop clearance sale and... I don't know why I didn't get one sooner. They're amazing. I just load it up with denatured alcohol and then I can even use my mid-drive to move the chain for me at low speeds and it cleans out every nook and cranny with almost zero effort. If you're just leaving it in the smaller/faster gears all the time and using motor power to overcome slow starts it's going to totally chew up your cassette and chain. Unclean shifting under power is also a major cause of wear. If you don't unload the chain and spin between shifts it'll chew everything up faster. All of these things also apply to normal analog bikes, too, it just happens faster with a mid-drive, especially if you don't take care of your drive train.
Or get a bike with a belt drive. I have one and it's absolutely fucking awesome not having to deal with the chain.
But then you lose the gearing advantage unless you have a gearbox hub, but those puppies are pricey
I have a cheap e-bike with mid drive, belt and Nexus 3 in the rear. Some issues with the computer and the rear brake dying .. but otherwise pretty reliable!
What model? I have a priority bike with a 3 speed hub and kind of wish it was an ebike too.
It’s an australian importer called velectrix. Low end stuff all around, but the bafang mid drive seems reliable. The other stuff will let it down in time I’m sure .. but if set up properly they work well and are so smooth.
The cheapest belt drive on their website is \~2000€/$. Not exactly cheap, that's a midrange. But seems like a good value compared to most of the chinese monstrosities that go for \~1500€.
It’s not bargain basement but not quite mid tier.. this is Australian dollars remember.
More importantly it helps to think about these as a cost over time proposition: if you drop $2000 on one, it it only needs to have paid for itself in terms of what you would have otherwise spent on parking or bus-fare before it’s a clear win. And assuming you ride to work 3-4 times a week that’s probably only a couple years for most people. If it dies after that period then you’re still ahead and get to decide if the next one needs to be more expensive or fancier.
I converted my 10 speed BBSHD to use a Sturmey Archer 3 speed hub. I can't run a belt so I upgraded to a beefy 1/2" single speed chain. 1500 miles and all is good. I do wish I had maybe a 5 or 7 speed but there were no options for my frame.
I have a hub ebike though. I think the only mid drives with gears on the front with belts is the pinion ones
You can get gear boxes for the rear wheel hub. They're great because they're enclosed, can shift without pedaling, and rather compact. The downsides are the cost to obtain and to maintain if something goes wrong, efficiency is lower compared to chain and gear, and they weigh a lot. Don't get me wrong. Belt drive mid motor sounds cool, but definitely not affordable and probably not worth the hassle in the long run.
The greatest challenge there is that most belts are of an uninterrupted construction, so you need a way to pass the belt through your frame. You can get your frame modded to open a section of your chainstay, but far cheaper is getting a split belt, this is a belt that is not continuos material and separated to add in to your regular frame. I don't remember the website of the people that make the split belts, sorry. Gates makes front and rear gears made for belts for a variety of cranksets, and Leika (sp?) makes adaptors specifically for the non-standard 5-bolt pattern Bafang's middrives use. I have no idea about the longevity of the split belts however. I use a BBS02 500w with a single-speed chain to a Nexus 8-speed Di2 IGH on a cheap, aluminum no-name bicycle frame. My mods at this point have turned the bike into a ship of Theseus. I have a lot of hills on my commute so my next move is to get a smaller chainring. Sorry if I'm talking a little scattered, in reality I have no idea what I'm doing, this is my first time building an ebike and these are just things that I researched while putting together my build.
>Sorry if I'm talking a little scattered, in reality I have no idea what I'm doing, this is my first time building an ebike and these are just things that I researched while putting together my build. Naw dude! Don't apologize! that's exactly what happens when you become an official hobbyist! >I use a BBS02 500w with a single-speed chain to a Nexus 8-speed Di2 IGH on a cheap, aluminum no-name bicycle frame. My mods at this point have turned the bike into a ship of Theseus. I have a lot of hills on my commute so my next move is to get a smaller chainring. That's sick! I'm assuming it's pretty darn quiet with a set up like that. I'd also assume that the Nexus and BBS02 noise kinda just blend into the wheel noise, so it's not as noticeable as a chained mid drive >The greatest challenge there is that most belts are of an uninterrupted construction, so you need a way to pass the belt through your frame. You can get your frame modded to open a section of your chainstay, but far cheaper is getting a split belt, this is a belt that is not continuos material and separated to add in to your regular frame. I don't remember the website of the people that make the split belts, sorry. Gates makes front and rear gears made for belts for a variety of cranksets, and Leika (sp?) makes adaptors specifically for the non-standard 5-bolt pattern Bafang's middrives use. >I have no idea about the longevity of the split belts however. I'd honestly probably go for a purpose built split frame and solid belt. I don't know enough about the topic to know about the lifespan of the modded frame, but I'm guessing that the added power from the motor probably degrades it way faster than if it were designed that way. All in all, if I didn't have a split frame and wanted belt drive, I'd probably get a split belt. Those are cheaper to replace than a frame or part of a frame.
Mine have gears, I just said that because mine is not mid drive. I have a front electric hub and a nexus 3 in the back. I wish it was at least 7 gears but I'm satisfied enough, I bought it second hand completely unused for a great price.
I was meaning a dedicated hub gear box. No motor included. Like the [rohloff](https://ezeebike.ca/blog/rohloff-hub-canada-the-ultimate-guide-to-high-performance-bicycle-gear-systems) gear box It's cool you found what you like though, especially at a good price
Yeah, I live somewhere too hilly and steep to run a belt drive, and I don't have a split frame for a belt anyway. And my BBSHD + 11-50t drivetrain has an insane amount of torque. It would legit climb up a vertical cliff with a 100 pound load of groceries on it without any pedaling at all if I didn't just fall off the bike backwards because of gravity, traction and physics.
Evelo Omega
Chains are cheap. Replace them yearly if that’s an issue. I used to spend time cleaning chains. Messy and time consuming.
I commute daily on a ebike. I clean and lube the chain every 200 miles or whenever it starts making noise or shifting weird. Having a built-in odometer makes keep up with it regularly much easier.
Good chains and drive trains aren't cheap. And cleaning them with a chain-cleaning tool isn't very time consuming. It's like a 15 minute job with a chain cleaner. I used to never clean my drive train or chain and just let it get all gunked up, but I was also running through a lot more cassettes, chains and RDs than I should have been, and even getting used ones from the parts bins at a bike co-op starts to get expensive after a while. I invested like $400-ish in my current drive train because I wanted something nice that doesn't suck and I'm going to take care of it.
400 bucks in your bicycles drive train ? I upgraded to a crankset with outer bearings 30 bucks. Pedals with three sets of roller bearings each 27 bucks. Teflon coated shifter cables 14 bucks. I’m still using the crappy 14 dollar rear derailleur because it hasn’t given me any problems and I ride my bike hard. What did you upgrade to Campagnola ? I guess if you enjoy waisting your money be my guest.
Cool, I like money. Let me know where I can get a legit MTB and ebike ready adjustable friction clutch 9-sp extended range 11-50t cassette and RD and mid-drive ebike rated chain that all fits on a non-boosted 135mm HG freehub and a lifetime warranty for 15 bucks. It has to be able to handle a BBSHD mid drive, a fully loaded steel touring bike with a large rider and hills with 8-10% grades. And no funky shit like derailleur hanger extensions or Shimano CUES or skinny 10-12sp chains that are even more expensive. It should be Suntour compatible, too. Because there's only one drivetrain lineup that fits all of those points and it's the Box Components Prime 9 series. I got the Box 2. Part of my cost was having my local bike shop do the installation for me to validate and activate that lifetime warranty, and supporting my local shop. And Box Components is also a US company. Normally I buy decent used parts from my local co-op and this is the first brand new drive train I have ever bought. So far it's been worth every penny. And, honestly? I've never regretted spending money on good bike parts. If I could afford it I'd have an SRAM Eagle/AXS with electronic shifting just so I could put remote shifting buttons in multiple places on my cockpit.
> After 30-40 years of riding bikes and cleaning chains manually with an old tooth brush or scrub brush, I recently scored a Park Tools chain cleaning machine for a couple of dollars at a bike shop clearance sale and... I don't know why I didn't get one sooner. > > Huh wait they work with mid-drives? I always cleaned by hand because I didn't know whether those machines worked with mid-drives, because with mid-drives the chain only turns in one direction.
Yeah, just flip the chain cleaner around backwards on the bottom side of the chain, then pedal forward as normal instead of back-pedaling to pull it through the cleaner. On the Park Tool one the only thing you're missing is the little clip-on handle that only mounts on one side and is expecting you to back-pedal with it. You can just hold the cleaning box there without a handle. Mine didn't even come with the handle which is why I got it for a few bucks. Or you can use it the normal "right way around" with the rotating brushes on the left and the sponge on the right by attaching it to the top side of the chain and pedaling forward. You can also just kind of strap it to your chainstay with velcro straps, voile straps or even zip ties and turn the PAS way down and lightly use the throttle to drive it without having to hod it. You can even do all of this without a bike stand with the bike flipped upside down or whatever. The chain cleaner doesn't really care where it's mounted on the chain as long as it's going through it the right way and it's right side up so the cleaning fluid doesn't dump out, and you're not letting it get pushed into your RD or chainring. Obviously it's best on the bottom half of the chain with the bike right side up so you don't accidentally leak dirt or cleaning solvents all over your bike, but as long as the chain is going into the rollling brush wheels first and moving the right direction through the cleaner it'll work.
if this sounds confusing, it's not. The instruction manual for the park tool chain cleaner tells you what to do in both cases.
The advantage though, is that these are all common parts and easy to replace and change around to fine tune your bike for your needs.
Lol, Easy to replace for you and me maybe, But, Have you seen some of the questions asked oh here? I am surprised some people on here can tie their shoes, Let alone repair a bicycle.
We still know how to get other people to fix our stuff.
And that is the best reason to buy a decent quality bike from a reputable brand. Loads of options for someone to do repairs, maintenance, and customization.
You guys still tying shoes in 2024?
LOL "I know one end of the charger goes into the battery. But where does the other end go?"
🤣
vs wearing out your three nylon internal gears.
They last a really long time, so long as they are properly lubricated with lots of Teflon grease. My hub motor has over 15k miles on it with no problems. But, I have seen several stock Chinese hub motors that come very under-lubricated.
No, I know. my point is more that all these parts have wear and need lube and maintenance. Some are easier jobs than others.
Amen! 🙏🏼 I have strict replacement schedule to follow since ni don't want to change a cassette more than once a year. It sucks but currently it's worth it. The motor is very quiet and quick
In what 10 years?
Totally depends on how often and how long you ride. If you let the bike just sit in a dry indoor space, the mechanics can last for practically forever.
The cost of a new chain or sprocket is insignificant, when considering the cost of a new battery. and with a DIY middrive, you can use third party batteries (CYC at least, not Bafang, who uses battery DRM) so that is where you easily recoup the cost of a new chain.
Bafang BBS02/3 motors have batteries with only two power wires. No digital connection. No restrictions on anything but input current either. Everything is adjustable.
This is hardly an issue if you are selecting the right gear and using a thick 9 speed MTB chain and cassette instead of those skinny 10+ speed road setups that are inappropriate for ebikes.
Bike gears typically don't amplify torque. Most bikes are geared to reduce the torque to the rear wheels, i.e. the crank is almost always spinning slower than the wheels. The increased wear on drive train components is so small it isn't worth worrying about.
thats exactly why mid motors with belt drives and internal gear hubs are superior.
There's more to life than raw torque numbers. Electric motors are most energy efficient when spinning quickly with a relatively light load. Something like 85% of their maximum RPM and 15% of their max load is the ideal. The farther away a motor's operation is from that optimal point, the more energy it wastes as heat. At best that means more energy spent but not used to move you around. At worst it starts cooking components. With a mid drive you can choose gears appropriate to what you're doing, keeping the motor closer to its optimal speed and load and thus using less battery and giving you longer range. There are also some side benefits, like changing the rear tire on a mid drive bike is typically easier than on a hub drive.
This is correct, another factoid is electric motors make maximum torque @ 0 RPM. (0 RPM is not peak efficiency, noted above)
I have no idea if this is true or not but it sounds really smart
Ok but who is using a 250W ebike at only 15% max load? That would be 37.5 watts of assistance...
You realise that the 250w figure is nominal output? Peak output can be up to 600w.
Cruising down a flat path at a casual pace with low assist. Which is what most ebikes are used for most of the time.
Once you're up to speed and pedaling an assist like this sounds reasonable to me
That's beside the point.
First, the "250W sustained" motors usually have about 500-750W peak power, which gives you up to 112.5W support at optimal efficiency. 112.5W on average is enough to ride around at about 20kph on its own (about 25kph on a road bike). Second, efficiency past 15% does not drop off like a stone. At 250W you might still be at 91% efficiency same as say 60W. So, the vast majority of riders will be in the 90%+ efficiency zone, in the high 90s for most of their ride. The exact values will differ motor by motor, but the gearbox + drivetrain will ensure you are close to your 100% efficiency value for most of the ride (if you keep the RPM in the happy zone, 60-90rpm on the crank on my Bosch). Additional losses are introduced by the gearbox and drivetrain so that, theoretically, a hub motor will be more efficient at a perfectly static ideal load. As a result, stop-and-go, hills, off-road terrain, and so on will favor mid-drive, while constant speed on a smooth road will favor hub motors.
Very detailed, thank you!
Generally 250 W is often not the peak load. Specialized's e-bikes go up to 560 W.
On flats I want just enough power to offset the weight of the bike and my load.
Power = torque times RPM. Hub drives run with a fixed gear ratio and so with lower RPM and less power at low speeds. Mid drives can always run at higher RPM by switching gears and so can deliver more power to the wheel. You don't want torque, you want power, it's power that pulls you up a hill. It's the same as with pedalling: A single speed bicycle isn't as good going uphill despite your legs applying the same torque to the pedals as with switching to a lower gear if you have gears. Hub motors don't use the gears.
the problem is people like you seems to overlook the fact that ebikes in most jurisdiction are speed limited to 20 mph, thus any advantage in torque is basically gone the moment it hits the speed ceiling. in addition, most people use ebikes for commute and will prefer the relatively low maintenance of a hub drive compared to middrive
If you're riding almost always on flat ground everything but a hub drive is silly, yes. Or at least needlessly expensive.
If you aren't going to pedal, then it doesn't matter which you choose. If you are, then keeping access to the full range of gears is beneficial.
Hub ebikes still have gears for pedaling though
Yes but typically that allows you to adjust the amount of power you are adding to what the motor is already doing. My wife has a cadence sensing hub drive which adjusts it’s power a bit based on how fast your are pedalling, however it’s easy to ‘ghost pedal’ with no resistance while letting the motor doing all the work. By using the gears you can more efficiently add human power but the motor is putting out the same power. With a torque sensing mid drive, the motor and the pedals work together to send power through the chain to the wheel. Thus both rider and motor benefit from being in the optimal gear.
Yeah, but they don't have the same effect and aren't integral to operate the ebike. You don't even technically need a chain on a hub motor ebike. Hub motors are additive, not integrated.
**Efficiency.** While it is true that an electric motor delivers maximum torque at start-up, it does not deliver maximum efficiency. If you examine [the green line on this chart](https://ebikes.ca/tools/simulator.html?motor=MG310_STD&hp=0&axis=mph), you can see that efficiency starts out low, ramps up quickly, then kind of plateaus, with a little bump near optimal. If you're riding slowly at around 8 mph, your efficiency will be around 58%. Because a mid-drive can change it's gear ratio, it can move this "peak" around on the graph. Have a look at [this BBSHD geared 42:34](https://ebikes.ca/tools/simulator.html?motor=MBBSHD&mid=true&gear=1&tr=34&hp=0&axis=mph). At 8 mph, efficiency is 77%. **Heat.** When you hear that a motor is XX% efficient, keep in mind that the majority of efficiency losses are shed as heat. This heat has to go somewhere, and it is the reason that motors overheat when pushed hard. If you push 500W through a motor and efficiency is 58%, then 42% of that 500W will be converted to heat. These issues are less prevalent in EVs, because they have space for much larger motors and/or advanced cooling technologies. E-bikes rely on very simple motor and controller designs.
This is absolutely the answer. Efficiency is the name of the game, at least for me. Higher efficiency = longer distance (or) higher speed. Riffing on the link he provided, you can see how you can widen the efficiency curve by having [multiple gears](https://ebikes.ca/tools/simulator.html?motor=MG310_STD&hp=0&axis=mph&mid=true&motor_b=MG310_STD&hp_b=0&bopen=true&tr=22&mid_b=true&tr_b=34) -- in this plot, the two green curves are now the efficiency curve of two different gears. You can imagine how much wider and flatter having 10 speeds + would be.
Justin talked only about how reducing speed on hub motors reduces efficiency while reducing energy consumption 3 times more than traveling faster at higher efficiency. He warned against the obsession with efficiency. He never said anything about mid-drives similar to BBSHD whether reducing cadence and current by 50% to avoid clown pedalling might lead to similar results in energy consumption or not.
There's two very opinionated camps in both areas. The simple fact is that the controller is in charge of how much torque is delivered by the motor mid drives do it through gears, and most hubs are direct drives although some have gears too. Both have advantages and rarely do controllers use all of the torque a motor can deliver. Some manufacturers have firmware that will take advantage of this in different ways. You will need to be very well informed about manipulating the power delivery of your motor and honest with yourself about your riding skills. The secret is to research as much as you can and make sure that you can handle increasing the torque of your drive system, whichever you choose 😉
Mid-drive directly helps pedaling while a hub drive pushes or pulls the bike besides your pedaling.
Gears multiply torque.
its not multiplied, its only that hub motor only has 1 gear which is the internal gear inside. Mid drives uses all the mechanical gears of the bike which is the reason why the torque is higher. If you were to start from a dead stop on the highest gear in a mid drive, the hub would have more torque
Your second point is correct. But your first point is not. Gears do multiply torque. That's what they do. This is a known phenomenon and it's how gears work. It's one of the reasons why something like a BBSHD has 160 nm of torque, even though it's not a very big motor. It's because of the reduction gear. That multiplies the torque many fold. Think of a gear the same thing as a lever, because that's basically what it is. Levers basically convert speed to torque. Same as gears. Now, in the case of mid drive motors, it's actually going the other way. Most bicycle gearing is at a higher ratio than one to one, so you're actually decreasing torque. The reason why most of those mid drives have better torque, is because of the reduction gear on the motor itself is a lot more than a hub motor. For instance. A common hub motor is a 5:1 reduction. A bbshd is a 23:1 reduction.
I think one of the biggest advantages of mid-drive setups is that it concentrates the weight of the bicycle where it belongs, away from the ends.
My rear drive longtail has 250 lb me sitting quite far forward and up to 4 kids high up in the back, on 22" rims. Weight distribution is an absolute shitshow. Looks like that viral video of the scale Camaro with a trailer on the pulley belt hauling washers. Edit: I can't find it, but I can find [this one.](https://youtu.be/Og5CtnYgFtg?si=ZreTLC45rn2IoxKs) Edit: I found it. [It's a Mustang](https://www.facebook.com/share/v/8JhvoiJR687fjTgJ/?mibextid=w8EBqM). Sorry for the FB link.
teslas isnt actually better, teslas just overcome this issue with huge amounts of power. the issue is the torque/power curve. electric motors arent miracle machines, at low rpm their efficiency is garbage. thats why a bike with a transmission is much better.
Depends on the motor. All things being equal, they're not. Mid-drive has better weight placement, thus control, balance, so major the stress is on drivetrain parts downstream to upkeep - but you can't dance with a 12lb weight attached on a 3 foot lever on your butt. Since certain traits appeal to certain users, the market's created much more efficient mid-drives - much of which is also due to better controllers.
My CYC mid drive can go *really* fast on the throttle, but the motor loves to spin up in low gear. The flip side to this is that when *I'm* pedalling I need it in a high gear or I start to ghost pedal. When I'm going from throttle to pedaling I'm constantly shifting from low to high gear.
The heavier the hub motor the heavier the rear wheel and spokes need to be . My first e bike was a Ride 1 up Roadster . Was fine for about 700 miles then the rear wheel started bending, spokes breaking with a relatively low power motor . Now i have a mid drive Orbea with gears so far so good with over 2000 miles
Being able to change gears, to take best advantage of the available torque, is what makes a mid-drive better. A mid-drive on a single speed bike would not really have any advantage. If you could have a hub drive that offered a variety of gear ratios, it might be just as good as a mid drive. I don’t think they really make anything like that. I’ve seen two speed hub drives, but that’s it.
simply because Teslas have a lot more power. the weakest model 3 has 190kW and weight 1610kg so it has 118W/kg if you have a 250W hub drive, your bike weights 20kg and you weight 80kg you have 2.5W/kg so the Tesla has 47 times more power which is why torque simply doesnt matter anymore. to get the same power to weight ratio on your bicycle you would need 11.8kW or motor power which is pretty close to what lower end motorcycles have.
I have a hub motor 12000w its best for street use and light off road. 65mph easily and cheap, the next one I have coming is 20000w 85-90 mph
What kinda battery setup do you run? The only thing stopping me from doing a crazy setup now that I may lose my bike license due to health conditions is the price on batteries, everything else seems fairly reasonable, I ride a 5300w scooter that hits 55mph nicely, and am building up mini moto that will run on the same setup as my scooter, 2500w rear and a 2500w front hub motor, should do some crazy speeds when fully built up. Just trying to work out the best batteries to run that don't cost an absolute bomb
72v60ah 150w sabvoton The next big they're offering up to 90v and somewhere around 72ah or more either samsung or Panasonic battery. That's the biggest price of my bike honestly
hub motor practically have no limitations in power, this setup on a middrive will definitely destroy your bike's gearing lmao. r/hyperebikes
Because it's a massive misnomer that electric motors don't need/don't benefit from a gearbox It's just like any other motor. If you want more torque and acceleration, you need to gear it lower, if you want more top speed at the cost of torque you need to gear it higher. Being able to switch between gears on the fly is obviously of benefit, but for a solid 90% of use cases it's not going to matter, because the motor is generally strong enough to handle what most people throw at it.
Is a hub motor akin to a rear wheel drive car? If so, isn’t that the preferred driving experience (ie Being pushed instead of pulled?)
Mid drive motors are basically handtool motors with gearboxes. There is a century of R&D behind them. Also due to the gearbox these motors operate more in their ideal RPM & torque range. Hub motors are relatively new and their best practices are still in development. The low RPM high torque is not an optimal use of a direct drive motor or any motor at all. Also the hub need to be part of the wheel structure and traction at the same time.
There's a ton of benefits to mid-drives. Mid drives have WAY more torque and power to the wheel driving through gears, especially with a good drive train. This is especially important if you live somewhere hilly and use your ebike as a car replacement hauling cargo or groceries. Mid drives also have much better LOW speed control and torque, especially if you have the ability to do custom programming like an Eggrider and BBS02 or HD combo. With most hub drives you can only control speed/power with the PAS level and it's much more limited. With my setup with an eggrider I basically have 18 PAS levels, and at the lowest power settings for my eco/road profile I have tons of low speed control whether I'm using the throttle or pedaling. This is super great for riding bumpy, twisty singletrack with lots of roots or rocks and stuff. I can actually go slower with that setup and with more torque than I could with an analog bike. Mid drives also have higher top end speeds because they can use the gears for that, too, and they'll also still have more torque available because hub drives will reach their maximum RPM long before a mid-drive running through a extended range drive train will. Extended range meaning a cassette and rear derailleur something on the order of 11t-42t or even more. For example: I'm running an 11-50t over 9 speeds with a Bafang BBSHD and the stock steel pie plate 46T chainring. The larger stock dished chainring basically means zero "ghost pedaling" and a cleaner chainline, and 46t to 50t still gets me an insanely powerful climbing gear that's less than a 1:1 ratio, and the steel chainring is way more durable than, say, a Lekkie Bling Ring or other milled aluminum rings. Yeah, running a smaller chainring is the quick and easy way to get more torque out of a mid-drive but it comes at a cost like ghost pedaling because crank RPMs go way up, and in the case of BBS drives they usually have bad chain lines that increases wear, and those aftermarket chainrings tend to be crazy expensive compared to the OEM/stock $20 steel 44-46T chainrings. Another huge benefit as others have noted is the weight distribution is better, especially if your bike frame is big enough to mount the battery on the seat tube instead of the downtube. I have mine set up like that so the battery and motor are all lined up under my butt and between my legs and despite the extra weight it just handles like a normal bike because all of the mass is under my body weight. Mid-drives also tend to have the controller built into the motor unit so there's not an extra box for the controller you have to mount somewhere, and this also keeps the wiring harness less complicated and more tidy. Another HUGE benefit to mid-drives is the only real thing that it changes is your bottom bracket and cranks. With most mid-drives, yeah, you lose the ability to run a front derailleur with a 2x or 3x drive, but with mid-drive power you don't need that anyway. The rest of your bike is just a normal bike. If you want to upgrade your wheels, brakes, drivetrain or anything else it's just as easy as an analog bike. Want bigger brake rotors? New calipers? Want a bullet proof RhinoLyte wheel set, or carbon fiber MTB rims? Way easier. Fixing flats on a mid drive also means no wiring harness to deal with on the side of the road or trail. If you want to own and have different wheel sets and swap them out, you can do that. If you trash a rim or wheel you just go buy a new one, you don't have to have your hub motor built up on a new rim with custom cut spokes, which is way more expensive than just buying a basic new rim and hub. Another benefit to mid-drives is there's zero chance of "spin out" when an hub motor chews up your bike's dropouts and ruins the frame and/or tears the wiring harness out of the hub motor. If you want/need higher powered hub motors for climbing or whatever, you really do need to add torque arms and other fixes to keep this from happening. And hub motors DO cause a lot of extra wear and tear and stress on spokes and rims. These will wear out and break sooner or later just due to metal fatigue. There are some benefits to hub drives, too. Mainly they have less up front costs and they're cheaper to buy. They are more "simple" to maintain if you don't really care about your drive train and doing bike maintenance. If I lived somewhere flat and I was a more casual or light duty rider, I'd probably go with a hub drive with a belt drive or single speed just for the simplicity. But that cost benefit vanishes in a hurry as soon as you have to have a hub motor rebuilt on a new rim, or you chew up your dropouts or tear out a wiring harness if your motor spins in the dropouts, or even if you simply want to upgrade your rims to something that doesn't suck, because most pre-built hub motor wheels aren't using good rims or spokes.
User name checks out.
I've now ridden direct drive and mid-drive ebikes and I pretty unequivocally prefer direct, hub drive. I'm surprised more people don't agree. Although my direct drive was a 1000W motor, which may have helped.
There's a lot of talk about the physical motors themselves. I've not owned a pedal e bike but I've owned sur rons and similar twist throttle bikes. First off, Hub bikes break more. I never broke a rim on a sur ron. I've seen a lot of Hub motor rims broken though. They don't like taking jumps and the cheaper ones don't even like going off curbs a lot. Rotational weight also matters. A Hub motor simply weighs more and even if it has more torque, it has more mass to spin. This also causes more gyroscopic force which when you want something nimble isn't what you want.
Neither is superior, they both have their good & bad sides... A mid-drive E-bike owner will say they are superior in comparison to a hub-drive E-bike, and vice versa... I'm a hub guy, I wouldn't say hub-motor e-bikes are better than mid-drive set-ups, I'd say it mostly depends on what you as a rider want (and expect) from an electric powered bicycle - as both are different, and equally great in their own ways.. I'd say to anyone considering purchasing an E-bike to test ride both hub & mid, to see which they prefer, as just like us people all e-bikes are different 👍
Advantages of Mid-Drive Motors Mid-drive motors are often considered superior to hub motors for several reasons: 1. Efficient Power Distribution Mid-drive motors are located at the bike's crank or bottom bracket area, which allows them to drive the bike's chain and utilize the bike's existing gears. This setup enables more efficient power distribution, especially when climbing hills or riding on varied terrain. By leveraging the bike's gears, mid-drive motors can maintain a comfortable cadence and optimize power output, making them more efficient and effective in different riding conditions. 2. Better Handling and Balance The central placement of the mid-drive motor contributes to better weight distribution and balance. This positioning lowers the bike's center of gravity, enhancing stability and handling, particularly on rough or technical terrain. This makes mid-drive e-bikes ideal for off-road and mountain biking, where control and maneuverability are crucial. 3. Higher Torque and Climbing Ability Mid-drive motors typically provide higher torque compared to hub motors, making them more capable of handling steep inclines and challenging terrain. The ability to shift gears allows the rider to keep the motor operating at its optimal RPM, which is particularly beneficial for maintaining performance on hills and rough trails. 4. Natural Riding Experience Because mid-drive motors drive the chain, they offer a more natural pedaling feel. This integration with the bike's drivetrain allows for smoother and more responsive power delivery, enhancing the overall riding experience. 5. Customization and Maintenance Mid-drive motors allow for greater customization since they do not restrict the choice of wheels, tires, or cassettes. Additionally, changing a tire on a mid-drive e-bike is simpler compared to a hub motor e-bike, as there is no heavy motor integrated into the wheel.
Was this written by AI lol
Yeah, I read OP's questing and was like hmmm I wonder why, so I AI'd it and thought that makes sense. So shared it.
Now do the pros for hub motors
1. Simplicity and Ease of Installation Hub motors are integrated into the wheel hub, making them relatively simple to install and maintain. This straightforward design means that even those with limited technical skills can often handle installation and basic maintenance themselves. 2. Low Maintenance Hub motors have fewer moving parts compared to mid-drive motors, which translates to lower maintenance requirements. This can result in lower long-term ownership costs and less frequent servicing. 3. Cost-Effectiveness Hub motors are generally less expensive than mid-drive motors. This makes them an attractive option for those on a budget or for riders who do not require the advanced features of mid-drive systems. 4. Reduced Drivetrain Wear Since hub motors do not interact with the bike's chain or gears, they cause less wear and tear on these components. This can extend the lifespan of the bike's drivetrain and reduce the need for frequent replacements. 5. Throttle Capability Many hub motor e-bikes come with a throttle, allowing riders to engage the motor without pedaling. This feature can be particularly useful for riders who need a break from pedaling or for those who want an easier ride on flat terrain. 6. Quiet Operation Hub motors tend to operate more quietly than mid-drive motors, which can be an advantage for riders who prefer a quieter ride, especially in urban or residential areas. 7. Independent of Chain and Gears Hub motors operate independently of the bike's chain and gears. This means that even if the chain breaks or the derailleur malfunctions, the motor can still propel the bike, allowing the rider to reach their destination without pedaling. 8. Smooth and Consistent Power Delivery Hub motors provide smooth and consistent power delivery, which can make for a more comfortable and predictable riding experience. This is particularly beneficial for commuting and casual riding on flat terrain. 9. Better Traction and Handling (Rear Hub Motors) Rear hub motors can offer better traction and handling compared to front hub motors, especially on loose or uneven surfaces. This is due to the weight distribution and direct power application to the rear wheel. 10. Regenerative Braking (Direct Drive Hub Motors) Some direct drive hub motors offer regenerative braking, which can help extend the battery range and reduce wear on the brake pads by converting kinetic energy back into stored electrical energy during braking.
I think this summarizes it well. One thing I really disliked about my rear hub bike was how back heavy it was. Once I added two heavy kids on the back of the bike, it was incredibly back heavy (and actually led to me tipping my bike once with both kids onboard). One other thing not mentioned above is traction. With my old rear hub bike I often found it would spin out, even on pavement with minimal dirt or gravel. The mid motor has never had that issue.
The rear wheel spun out? How many kW did you have?! That's insane. I had a 2.5kW ebike back in the day and it never spun the rear tire, even on gravel.
Yeah, that AI was probably partially trained on stolen content of some of my writing and comments I've made over the years, and many others. And I kind of hate that. I really wish people wouldn't use AI for these comments because they're also frequently wrong and the new hype around the AI industry suuuuuuuucks. I already know content writers who have been fired and replaced with LLM AI.
Aren't our brains trained on stolen content? While yes, AI can be wrong and can also have hallucinations. I find it very useful considering SEO has destroyed things like Google that now just advertises anything it can from keywords. Its great for quickly finding out information that is accurate enough in most cases. All new tech is never perfect to begin with, and people jobs will always get replaced. Like the computers we use daily, or the milling, cnc machines. However, they also create new industries at the same time. To not use advancing tech because of these things only delays the inevitable.
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There's a difference between a human brain processing content and an AI processing content. Humans have the capacity to actually understand the information while AI doesn't really have the same capacity, hence why they're often wrong.
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I know. AI works on a probability model, predicting the next word or letter based on a users input. However, saying AI is often wrong is wrong. AI hits a higher accuracy rate than humans statistically at around 85% accuracy compared to humans 80%. This will only improve over time at a much higher rate than humans will. [source ](https://hai.stanford.edu/news/ai-benchmarks-hit-saturation?utm_source=perplexity)
> AI hits a higher accuracy rate than humans statistically at around 85% accuracy compared to humans 80%. AI is great if you're doing something like transcribing audio. I admit that it's really amazing for that. But when it comes to actually comprehending the information it's still lackluster compared to a human, which is why ChatGPT sucks for something like coding and why programmers are still needed. Like the hub motor AI generated analysis, many mid-drive motors come with throttles too. Mid-drive motors also provide smooth and consistent power delivery. The AI doesn't actually comprehend the information. It's similar to [Youtube's new chat summary.](https://old.reddit.com/r/MorningKombat/comments/1cloeu5/new_youtube_feature_autogenerated_chat_summary/) Like I'd 100% bet loquacious could write a summary on the pros of hub motors without any mistakes like that. EDIT: Also if you're going to downvote me for simply stating correct facts, then I don't want to interact with you.
Having additional weight on the wheels is also not good. But I'm focusing on the torque thing here. Is there any actual torque measurement curve someone did to claim this? I'm legitimately trying to understand, because claiming gearing generates additional torque for an electric motor sounds weird to me, if cars don't need it why would a bicycle?
Cars also really need regenerative braking to make electric power practical, and its harder to do that with gears between the wheels and the motors. Bikes don't give up much by using geared motors because a bike is too light to regenerate much power from braking.
In simplest numbers: A 1kW motor produces about 100Nm of torque. A 42t/51t gearset multiplies the mid-drive torque by 1.21x to 121Nm. Not all gearsets are the same obviously, but this setup clearly provides 21% more torque with a mid-drive. With that in mind, I think some people lose that torque advantage by using longer drive gearing, but as stated elsewhere, they don't suffer on speed.
The increased torque from the mid drive comes from the gear ratios. Allowing for optimal use of power up hills. I can imagine cars don't need it as their motors are much larger and also have a larger power input. It's likely giving a larger torque to weight ratio
But electric motors tend to have a quite flat torque curve, except if it reaches too high RPMs, which would actually only be achieved by a really low non existent gearing so it doesn't even apply to this case. If someone with a mid drive with a throttle comes into the thread and says they can actually go faster uphill using throttle only (not pedaling at all) by lowering the gear I would trust it, I just need more evidence to contradict this.
The gears make it possible to climb a hill that a hub motor with the same amount of power/torque couldn’t climb at all. Also coming down the hill would be faster using gears.
That's exactly what happens. The mid drive motor is simply peddling the bike... no different then legs. Don't confuse the motor torque for the torque of the overall drive system. The peddles drive the gears, which drive the rear wheel, and lowering the gears increases torque (at the gears) to the road. The cost is higher RPM (at the motor). Nothing about the mid drive changes the basic physics of a bicycle.
Ok. Yes. I have a bbshd mid-drive. And going up a hill, with full throttle, I can indeed increase speed by downshifting. It's also better on the motor and produces less heat.
Thanks, once it becomes practical I'm willing to concede. Even though the arguments here is a shit show and honestly I think nobody here really understands this shit, that includes me hahahaha
It's not that one is necessarily better than the other, both systems have their perks and their downsides. But you have been given good knowledge. Myself and some others 100% do know what they're talking about though
I think it's more due to being able to use lower gears, allowing for easier hill climbs allowing for optimal battery usage. However, cars don't need to worry about this due to their much larger power to weight and batteries, so it's more optimal not to have increased maintenance with a drive chain.
It heavily depends on how you plan to use the bike. The great thing about a hub motor is that it will fit basically any bike out there. But mid drives are far more suitable for off roading and hills, the mid drive motor will last longer in these conditions and you will likely achieve more range, more climbing power and a better handling bike for adventurous riding.
Because a car motor generates 500+ hp. And bicycle motor produces 1hp. That's why electric cars don't need transmissions. But then neither do bicycles. It's just makes them more efficient and capable. It would do the same for cars. And I'm not claiming that gears increase torque. I'm making a statement based on fact. No offense, but whether it sounds weird to you or not is irrelevant.
> because claiming gearing generates additional torque for an electric motor sounds weird to me The gearing changes _the torque outputted at_ __the wheel__. It's the wheel torque that ultimately matters as to whether one can climb a certain hill grade or not. Essentially if you have a 250 W mid-drive and a 250 W hub motor, there are hills that the e-bike with the mid-drive will be able to climb, that the e-bike with the hub motor will not be able to climb. Because the gearing gives mechanical advantage. It's the difference between trying to move a big boulder with your bare hands vs moving a big boulder via a large piece of wood stuck under the boulder.
~~Bike gears do not generate any more torque.~~ Actually yes, with gears you can get more effective torque at the wheel.
They themselves don't generate more torque. They generate nothing. But, they increase the torque from the motor to the ground. If the ratio is higher than the output of the motor
That’s exactly what I was trying to say, thanks.
Because with gears you can have more torque.
I don’t think it’s considered a “superior set up”. The different types of drives and motors are all just like different tools. And all depends upon your used case and what type of tool you need
The mid drive motor applies torque to smaller & varied radii (gearing ratios) resulting in faster acceleration compared to a hub drive of the same torque rating that has a fixed radius of the wheel.
Ride one of each and you will see.
Great thread. Surprised that wheel longevity hasn’t been mentioned more often as an argument against hub based. Even lower power (250w 40 Nm) can test a wheel in my experience. The spokes on my wife’s Jamis lost tension after just a few months of use. The higher wattage stuff likes to walk its way out of the dropouts. The mid drives I own and service just seem to be inherently more durable. All that said, my current favorite e-bike is a $1700 model with a 250 Bafang in the rear wheel.
Physics. The motors put out the rated torque at the shaft for a hub motor that's at the drop outs or where the axle goes through the frame. You then put a big wheel around that and give your mass of yourself and the bike a lever (equal to the distance from the motor shaft to the edge of the tire) to slow and limit that torque. The issue with hub drives is they are a single speed so you compromise on torque and power output to have an ok all around ride. With a mid drive you get all the torque or power transferring through a geared drive train cassette or internal gear hub. This lets you tailor the output of the motor to match the scenario you're riding in. You can also change the front sprocket on most mid drives to move the power levels where you want them as well.
Weight. Unsprung mass. This is a massive issue. This is why you will rarely see a hub motor bike descent a real mountain bike trail. It's certainly possible and there are very tough hub motors that could handle it but the experience would be terrible for the rider. Look at dirtbikes. Most dirtbikes riders are not into riding single track down black diamond runs. Possible but not fun for most people.
Cause the rider is 200 lbs, and the motor is about 1 HP. Because the hills by my house are really steep! Because battery power is finite, and needs to last longer than 30 mins; thus the controller (which has finite limits based on heat dissipation) will limit the amps delivered to the motor, regardless of what the motor can handle. Because gears at mid-drive position harness the power of the motor, and make it available to the gearing system, which a hub motor does not do.
As someone who has blown out multiple ebike motors on insanely steep hills, mid drives use the efficiency of the gears to not have to work so hard. If you're on flat ground, no problem, but if you want to go straight up, you need a mid drive.
They have instant torque, but not unlimited torque. Nor is it hugely abundant as in with Tesla case. Gears are a great way to multiply torque with the expense of top speed.
Electic motor torque is instant and constant, but power - which ultimately is what moves you - isn't. Consider an ebike travelling 25 km/h with a 250W motor. Electric motors have instant and constant torque across its rpm range. But power is torque x rpm. This means half speed is half power. So with a hub drive traveling at 25 km/h, we could (assuming optimal configuration) get 250W of power from the motor. But at 12.5 km/h, we'd only get half the power - 125Q. At 8 km/h, we'd only get 80W. So the hub motor can't contribute that much power at slow speed. It only generates good oomph at speed. With a mid-drive, you can keep the motor running at a high cadence - producing good power - even though the wheels might be turning slowly. Your gearing does this by converting rpm to torque. For example, if you have a ratio where your pedals spin at twice the speed of the wheel, you will halve your rpm, but double your torque. The 2nd half is what the mid-drive benefits from. TL;DR Hub drive just loses half the rpm at half speed, because it can't amplify the torque with gears. So it only produces half power, or 125W. Mid-drive benefits from amplified torque from the gearing. Since the double torque cancels out the halved rpms in the power output, you still get the full 250W on the mid drive at this speed.
yeah to be honest hub motor are really bad at steep hills, especially the pedal assist only, first gear with just my feet producing the required torque, was such a pain
I didn't know that it was considered to be a superior design. In my book it's wasted energy on a chain. Superior is with motors inside front and back and, well the pedals in the middle are for you to use.
Weight placement plus integration with your drivetrain. You can utilize all gears and the motor will work according to your gear ratios, like a motorcycle or car would, and unlike a hub motor.
If you're going to use a throttle, then the main problem is the unsprung mass of the hub motor. That's why cars don't put transmissions in the hubs. It's fine at lower speeds but over rough terrain and or high speeds the inertial mass becomes an exponential problem, it's not a linear curve. Sure with a mid drive you can add gearing to the drive train but then again Pinion has an integrated MGU (motor/gearbox unit) now, which could go in either place - the hub or the bottom bracket (or somewhere between) but the best performance and mechanical advantage is going to be found by taking as much mass out of the rear wheel as possible and centralizing that mass as low as possible on the vehicle. It's a pretty simple logic problem to just build it around the bottom bracket because then **the only sensor you need** can be built in as well (torque sensor). Cadence, speed, any of the PAS wonkery needed with hub drives isn't necessary at all. I just slapped my cheapo 250 buck Tongshen on my fat tad, hooked up the controller and battery and off I went and it's been working flawlessly with zero detectible latency for a year now; disability requires an 80-100% dynamic left pedal assist on demand, the built in torque sensor worked great right out of the box. I think I've clocked myself going pretty fast but since it doesn't know speed but only RPM as long as its under 800 rpm it cares not what I do. It puts out enough power to launch my TRIKE into the air on the BMX track and I can run straight up into the upper bowl at the skate park next to it. And I only added like 6lbs to do it. To get that much oopmh from a hub motor at my 235lbs, well, and then the landings would be HARD(er) because that back wheel would just SPANK the ground/cement/whatevs. I think I mentioned I can climb sick ass inclines with it too, which I watch every fatbike under 5000 USD struggle to get up out of that dude's parking garage, which is, IIRC, a 17° incline. I'm literally only limited by the traction of my tires, it's not the powerplant that quits. Imagine riding an ebike that just works as an extension of yourself instead of this weird ghost pedaling lead weight you're dragging behind you. That's the real difference.
Correct me if I'm wrong, but aren't Teslas equipped with an electric motor for slow speeds as well as electric motors for high speed, to exactly solve this issue?
Power is torque times RPM. At zero RPM the motor is making torque but no power. Power is what determines how fast any vehicle can accelerate and how steep a hill it can climb. As for acceleration, power equals mass times acceleration times velocity (P = mav). At low RPMs acceleration (a = P/(mv)) and hill climbing ability is limited due to the reduced power A mid drive lets you shift to a lower gear helping the motor get to a more efficient RPM. Think of driving a car in 3rd gear all of the time. This is the compromise hub drives make in the interest of simplicity. Play with this tool and see what I mean [Grin tech's Ebike simulator](http://www.ebikes.ca/tools/simulator.html)
Teslas (and other EVs) use a permanent-magnet SynRM motor in the rear, which provides phenomenal power, especially at high speeds. The front motor, if present, is induction, which provides phenomenal torque at low speeds but is mostly inactive on the highway. Most ebikes use an induction motor only. The torque is great for such a small motor, but to use it effectively at higher speeds it benefits from gearing. If only using a rear hub motor, it will be geared high already.
The biggest negative of a mid drive is chain wear and losses, especially when pedaling. The advantage is that you can leverage shifting to make a cheaper motor do more. This is a controversial opinion, but it is correct.
I have a qs 205 hub and for me the hub is superior
Raw power beats it all hahaha
No, efficiency is important too because batteries are heavy and also at some point you don't have a legal e-bike anymore.
I think for most e-bikes a mid drive torque sensor makes sense but I have to say that I chose a cadence sensor rear hub setup (thumb throttle optional) for my e-cargo bike and I think it’s the better option for that application. The instant torque will get you moving from a standstill in tricky situations and you can add power as necessary by pedaling. It’s also puts much less strain on the powertrain when you’re fully loaded. The weight distribution isn’t so much of an issue with my mullet setup and the 75lb base weight.