Hub motor vs mid, driveline wear?

Would it be correct that the Stromer system actually prolongs chain/ sprocket intervals ?
—Compared to non assisted pedal power wear: as the boost from the hub sort of balances the the torque/pull from the chain??
You are pulling chain forward with drive but motor is powering wheel forward which relieves or balances some of that pull?

— And X2 for wear when compared to mid-drive road bike It will eat components even faster. All that extra torque on chain and cogs

— And X5 for mid drive mtn bike?? Which will gorge on the driveline from all that low gear torque multiplication.

My Stromer chains seem to last very long time. I lube and wipe down chain and sprockets with dry cloth after every ride.....any dirt on chain ext seems to be the real killer.
As others said, mid vs hub discussionrarely highlight this but it seems like a big deal.

Thoughts?
Belt drives would be much needed addition for mid drives, huge improvement
 

Alaskan

Well-Known Member
On bikes, chains, cassettes, brake pads and brake rotors are all wear parts that need to be cared for and periodically replaced. How you ride them, how you well you clean, lubricate and maintain them, all effect how frequently they need replacement. There are two other factors that influence the frequency of replacement. One is the quality and materials of the parts in question. The other is whether the motor transmits its power through the drive train or if it powers the wheel by being mounted directly to a wheel, bypassing the drive train.

Mid drive bikes go faster and further using smaller motors and less battery power by leveraging their effort in a more seamless way along with our effort through the chain and cassette to the rear wheel. As such the extra power being conveyed through the chain, results in shorter chain life. A belt drive will last quite a bit longer but will only work with fixies or internally geared hubs, It will not work with a derailleur.

In case a chain breaks, you can easily carry a spare chain or just a quick link that will get you back on the road. Belts to do break and when they do you typically have to order and wait for a new one. You can find a replacement chain for half the money at just about any LBS. Belts and internally geared hubs are quite a bit more expensive than chains and cassettes.

An ebike will handle and steer better if the added weight of motor and battery are centered between the wheels rather than sitting on the rear wheel, which unweights the front wheel somewhat, resulting in reduced traction for steering. Rear hub motors put the weight in the wrong place for optimal bike performance. Rear motor setups are quite a bit less complicated and less costly. Very few mid drive bikes have a throttle, you must pedal to move.

Key takeaway: It's complicated. Each setup has its merits. Know the differences and make the right decision that matches up with your needs and preferences.
 

Johnny

Well-Known Member
Would it be correct that the Stromer system actually prolongs chain/ sprocket intervals ?
Yes very significantly.

—Compared to non assisted pedal power wear: as the boost from the hub sort of balances the the torque/pull from the chain??
You are pulling chain forward with drive but motor is powering wheel forward which relieves or balances some of that pull?

True. The worst case wear will be equal to a regular bike. For the most of the time hub motor will have significantly less wear. When the hub gives support it actually decreases the tension on the chain.

— And X2 for wear when compared to mid-drive road bike It will eat components even faster. All that extra torque on chain and cogs

Yes. Mid drives transfer all of the power through the chain so the effect is the exact opposite of the hub drives. For mid drives , the wear on the chain is significantly increased compared to regular bikes.

— And X5 for mid drive mtn bike?? Which will gorge on the driveline from all that low gear torque multiplication.

For mtb's mid drives are the best for several reasons. The main advantage is mid drives make use of the gearing hence will be easier to cover/adapt to gnarly terrain. And weight distribution may be preferable for mtb'ing since the bike is getting tossed around at quite frequently( however the rider weight has a far more significant effect on this compared to the bike itself) .

My Stromer chains seem to last very long time. I lube and wipe down chain and sprockets with dry cloth after every ride.....any dirt on chain ext seems to be the real killer.
As others said, mid vs hub discussionrarely highlight this but it seems like a big deal.

Agreed. That is why I have switched to wax and so far it has been amazing. Very little to no dirt gets on the chain and so far no significant measurable chain wear after 1000 miles.


I have to address a couple of false statements here.

Mid drive bikes go faster and further using smaller motors and less battery power by leveraging their effort in a more seamless way along with our effort through the chain and cassette to the rear wheel.

This sentence is completely false.

First of all mid drives do not go faster and battery consumption completely depends on how the bike is ridden, the motor parameters and speed. If anything quality hubs are going to be faster since they do not suffer from drivetrain losses. For the same reason at higher speeds hubs are also more efficient. At very low speeds(like when doing a very steep climb) the hub runs at lower rpms at which it's output decreases. At these low speeds the drivetrain advantage of mid drives come to play, the mid drive rpm depends only on cadence hence as long as there is a gear that will keep the cadence at a level (say 60+ rpm) the motor still be in its high output and efficiency band hence will be more efficient.

In short at higher speeds hubs , very low speeds mid drives have an advantage.

An ebike will handle and steer better if the added weight of motor and battery are centered between the wheels rather than sitting on the rear wheel, which unweights the front wheel somewhat, resulting in reduced traction for steering. Rear hub motors put the weight in the wrong place for optimal bike performance.

This argument is flawed because it does not take into account the riders weight. If we were talking about mtb's this argument up to a point may have been true because on uneven terrain, the bike itself having center of gravity close to the center may help the rider to shift the center of gravity(the bike and the rider) a bit easier. When the riders want to hop, change the direction of the bike, center of gravity of the bike itself may again help.

However a rider weights usually 3 times more than the bike (sometimes much more) hence the center of gravity will be close to the rider's own. Hence geometry and riding position will be the dominating factors here and one can not suggest that steering will be better for a mid drive on smoother terrain. Since the power is transmitted via the rear wheel one may even argue that the increased weight will improve traction on the rear wheel.

More importantly, it is possible to achieve a good weight distribution with hub motors too. The placement of the heavy battery enables the manufacturer to play with the weight distribution significantly. As a matter of fact Stromer has excellent steering characteristics, on the road it is significantly better than my mid drives. And this is not only my opinion, each one of my friends had the same conclusion.

Rear motor setups are quite a bit less complicated and less costly.

Completely false.

As a matter of fact high quality hub setups like Stromer are more complicated and more costly. With a mid drive everything is enclosed(controller, sensor and the motor) in the same place and it is easy for a bike manufacturer to design the frame. The only necessities are compatible housing for the motor to be welded in the place of the bottom bracket and down tube enlarged to accommodate the battery.
On the other hand, the motor on Stromer for example is completely separated from the controller and torque sensor. So the frame has to be designed to accommodate the tmm sensor, cable integration is quite a bit more complicated and the controller is custom designed to fit the down tube.


Unfortunately comments like these are from lack of knowledge, experience and unjustified bias from what people read on the forums.
 
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legsofbeer

Active Member
Mid drive bikes go faster and further using smaller motors and less battery power by leveraging their effort in a more seamless way along with our effort through the chain and cassette to the rear wheel.
Nope, this violates Newton's first law of thermodynamics, and also common sense. If you're going to put out a fixed amount of torque, is it better delivered directly to the wheel, or through a geared chain that will inevitably have a bit of loss? Now, I'll cheerfully agree that mid-drives might have lighter, torqueyier motors, that kind of cost 4-6 times as much as a geared hub drive, but that ain't what you said.
 

almikel

Active Member
Region
Australia
I'm a newbie to e-bikes - 6 weeks in to ownership of a mid drive Giant Revolt and loving it!

As @MinnBobber discusses in his original post, mid drives have to transfer all motor torque through the drive train (front chain ring/chain/cassette etc) - so those components suffer additional wear and tear, compared to a hub drive.

When I started investigating e-bikes to replace my acoustic bike, this was a major consideration, and a hub drive bike was my 1st preference.

On test riding an Orbea hub (direct) drive I was very disappointed with the lack of assist it provided on the steepish hills I found on my test ride.
To be fair, I also took out a Focus mid drive immediately afterwards, and although it had a "bit" more pull up the hills, neither gave me the assist up the steep hills I was looking for.
At that early stage of my research I wasn't aware that geared hub drives existed...

...I was also trying to reconcile why the hub drive had such little torque/assist up steep hills when back at uni we learnt DC motors are capable of delivering max torque from zero revs...of course it's about the motor controller limiting the current...since max current flows through a stalled motor possibly resulting in smoke getting out...and we all know once smoke gets out it's extraordinarily hard to put it back inside again :(

I went looking for mid drives that had enough torque to get me up hills - I'm sure there's geared hub drives that would do the same, just not in a drop bar road/gravel style bike available in Australia.

Nope, this violates Newton's first law of thermodynamics
I'm a big fan of Newton and the laws of thermodynamics, but you're mixing the two together.
Newton created the laws of motion back in the 1600's
The laws of thermodynamics came later in the 1800's

cheers
Mike
 

fooferdoggie

Well-Known Member
Y

First of all mid drives do not go faster and battery consumption completely depends on how the bike is ridden, the motor parameters and speed. If anything quality hubs are going to be faster since they do not suffer from drivetrain losses. For the same reason at higher speeds hubs are also more efficient. At very low speeds(like when doing a very steep climb) the hub runs at lower rpms at which it's output decreases. At these low speeds the drivetrain advantage of mid drives come to play, the mid drive rpm depends only on cadence hence as long as there is a gear that will keep the cadence at a level (say 60+ rpm) the motor still be in its high output and efficiency band hence will be more efficient.

In short at higher speeds hubs , very low speeds mid drives have an advantage.
well a mid drive motor tends to spin closer to the idea rpm more then a hub will over more speed ranges since its s so geared. the speed is dependent on the gear your in not the speed of the motor. if your peddling at 80rpm the motor is going to tun the same speed with whatever gear your in. a hub motor only gets efficient when it is in the max speed.
 

bluecat

Well-Known Member
well a mid drive motor tends to spin closer to the idea rpm more then a hub will over more speed ranges since its s so geared. the speed is dependent on the gear your in not the speed of the motor. if your peddling at 80rpm the motor is going to tun the same speed with whatever gear your in. a hub motor only gets efficient when it is in the max speed.

Explaining the advantage of a gearless hub drive over a mid drive if it comes to commuter bike is like Eulen nach Athen tragen.

Thanks @fooferdoggie for your statement. For the rides, this is the key to feel comfortable on a fast commuter bike. You can ride at Stromer speed with the cadence you personally like best. Some did replace the 52T chainring with an even larger - to ge a more lazy ride wit slow cadence and high speed. All this doesn't care the motor - as he is independent from the drivetrain.

The complete opposite with a mid drive: The motor is directly bound to the riders cadence. The rider has to take care he's pedalling in the motors comfort zone if he is at top speed. Otherwise, the motor has poor efficiency, which will end up in overheating.
 

fooferdoggie

Well-Known Member
Explaining the advantage of a gearless hub drive over a mid drive if it comes to commuter bike is like Eulen nach Athen tragen.

Thanks @fooferdoggie for your statement. For the rides, this is the key to feel comfortable on a fast commuter bike. You can ride at Stromer speed with the cadence you personally like best. Some did replace the 52T chainring with an even larger - to ge a more lazy ride wit slow cadence and high speed. All this doesn't care the motor - as he is independent from the drivetrain.

The complete opposite with a mid drive: The motor is directly bound to the riders cadence. The rider has to take care he's pedalling in the motors comfort zone if he is at top speed. Otherwise, the motor has poor efficiency, which will end up in overheating.
yep I see I wrote the mid drive motor is slower I meant faster. bosch tends to nudge you if your spinning too slow.
 

Johnny

Well-Known Member
yep I see I wrote the mid drive motor is slower I meant faster. bosch tends to nudge you if your spinning too slow.
It is not. At higher speeds(of course there is a limit to this) hub is already in its efficient band and does not suffer from drive train losses so if anything hub will be faster.

Also as @bluecat said, while drivetrain gives a big advantage to mid drives on the lower speeds, they are cadence sensitive. So when your cadence fluctuates this time mid drives will suffer an efficiency penalty.

So you pick what you like best, one is speed the other one is cadence sensitive.
 

bluecat

Well-Known Member
yep I see I wrote the mid drive motor is slower I meant faster.

What I like most is hunting down mid drives on my daily commute with my 11 years old Stromer:


If you watch on a tiny device, you'll not see him at the beginning. He is far ahead of my. He is sporty and rides with full engagement. It takes a few corners until I catch him up. He has perfect rider position (watch his legs) and high cadence. But I passed him easy.

Later, I was waiting, because there is a normal climb ahead. I followed him closely and it was clear, he goes with full strength. But I had still some force left...
 

fooferdoggie

Well-Known Member
What I like most is hunting down mid drives on my daily commute with my 11 years old Stromer:


If you watch on a tiny device, you'll not see him at the beginning. He is far ahead of my. He is sporty and rides with full engagement. It takes a few corners until I catch him up. He has perfect rider position (watch his legs) and high cadence. But I passed him easy.

Later, I was waiting, because there is a normal climb ahead. I followed him closely and it was clear, he goes with full strength. But I had still some force left...
I get passed now because I am more focused on getting my heart rate up and keeping my wattage output as high as I can on the second level of assist its hard as I would have to maintain about 25mph to do it and its hard to find places to be able to keep that speed.
 

almikel

Active Member
Region
Australia
I get passed now because I am more focused on getting my heart rate up and keeping my wattage output as high as I can on the second level of assist its hard as I would have to maintain about 25mph to do it and its hard to find places to be able to keep that speed.
sorry foofer, there's not enough punctuation in your post for me to to understand what you're saying...
...did you mean you can't maintain 25mph (40km/h) due to the route, but others still pass you?...presumably unsafely?

Apologies - I really struggle to understand the context with books that don't have punctuation (eg James Joyce, Tim Winton).

If I understand you correctly, why not just drop back to the 1st level of assist to keep your heart rate up and wattage output high?

Mike
 

fooferdoggie

Well-Known Member
sorry foofer, there's not enough punctuation in your post for me to to understand what you're saying...
...did you mean you can't maintain 25mph (40km/h) due to the route, but others still pass you?...presumably unsafely?

Apologies - I really struggle to understand the context with books that don't have punctuation (eg James Joyce, Tim Winton).

If I understand you correctly, why not just drop back to the 1st level of assist to keep your heart rate up and wattage output high?

Mike
sorry my communication skills are horrible. its hard to keep 25mph because of safety or places you can really keep that speed. when I drop back to the lowest level I lose a lot of speed I get a better workout but then I average about 15.5 mph. I need to buy the Nyon to be able to change the assist levels. but its not a huge deal.
 

siclmn

Member
There is a lot of bla bla bla in these posts. I believe that my ST-2 is still one of the fastest bikes out there. I am not talking about some of those bikes that claim to do 40 to 60 mph. They might do that for a short time and then the battery will be dead. But I can still do a hilly high speed 70 mile ride with the fast guys in the bike club and pass them whenever I want. I still have 10% battery left after that. On flat ground I am sure that I still can get 100 miles in. I do pedal hard for the whole ride. When I am not on the ebike I am on a regular bike and they must wait for me a short time on the top of hills. I always ride about 90% in level 1 and that is how I get the maximum range from the battery.
 

bluecat

Well-Known Member
I believe that my ST-2 is still one of the fastest bikes out there.

What I've done shown in the video above is also easy with an ST2. To be fast is not only what you read on the display (like I did on the ST5), it's also acceleration, speed in the corners and the capability to stop, if needed. Competing with the mid drives is always fun, regardless of what Stromer I'm riding. The sole mid drive which gives me a real challenge was the Super Commuter+ 8S. If an athlete rides on this bike, he is not so easy to beat. Alle anderen Tretmühlen fährst Du mit einem ST2s oder ST5 Stromer in Grund und Boden.

ST5_full_speed_ahead.jpg