Electronic Shift Systems and E-Bike Drivetrain Longevity

[Butane]

I posted a similar thread in the Specialized forum but I think this is more of a general question as it can really apply to all EMTBs. I am competent at reducing the torque on my cranks when I downshift on hills on a regular MTB, but I have found it essentially impossible to downshift on a hill with my Levo SL without it feeling really hard on the chain and cassette. I can tell these won't last very long at this rate and I am curious if those of you with electronic shift systems like SRAM AXS still have this problem? I have heard that it times the shifts to be much less stressful on the drivetrain, which to me would mean a much better fit for an e-bike.

Anyone have experience riding with both and care to share if the electronic shift systems are in fact much easier on the drive train on EMTBs?

Thanks!
-Butane

 

[Jimbo Vills]

Doesn’t matter where you post. Just need to learn to shift bro ???

 

[Butane]

I'm ignoring the butthurt and socially deficient members of this forum in leu of possibly getting some actual advice.

From a BikeRadar article:
"Like the other AXS stablemates, the GX version benefits from a more forward design that increases chain wrap around the cassette.

This should improve shifting performance and help increase chain and cassette longevity because more of the chain is in contact with the cassette and jockey wheels in any given gear, compared to a derailleur designed to have less chain wrap."

Source: SRAM's GX Eagle AXS is the cheapest wireless groupset yet

This is ideal for an e-bike drivetrain is it not? I also remember reading somewhere that the AXS system timed it shifts to reduce wear on the drivetrain, but I could have misinterpreted that or it could have been a different electronic shift system I was reading about.

 

[Butane]

It's really only moments where I am on a hill, and that hills grade increases so I have to drop another gear. Normally on an standard MTB I would pedal hard for a second and then downshift while I let off torque on the cranks so that it shifts smooth. When I try that on my SL, when I let off on the torque it still feels like the motor is applying a lot of torque to the crank even though I'm not, and it make the shift crunchy.

 

[Gyre]

I can't speak to AXS yet though I have experience with mechanical and electronic cable-actuated shifting.

The main thing you'll get from an electronic shifter is really good consistency with your shift points and perhaps faster shifting. Those can only help with your issue, but I don't think either would really solve it. The chain wrap advantage with the latest AXS is interesting. I don't know whether it would noticeably help.

It sounds like your Levo has a hell of a lot of overrun. Assuming the bike is healthy and working as intended, I'd investigate whether the overrun is adjustable in any way or if it's totally fixed.

One thing that I'm confident will help is switching to Shimano 12-speed (cassette and chain). It's simply meant to be better at shifting under load by somehow spreading out the load between your current and selected cog. It's not the silver bullet Shimano marketing would have you believe (you can't get away with being totally hamfisted - DAMHIK), but it is more forgiving than Shimano 11-speed and X01 Eagle (whether traditionally or electronically cable-actuated). If you have an acoustic bike with Shimano 12-speed or know someone willing to lend a rear wheel that does, try swapping the wheel /chain / sensor magnet for a day.

 

[Mteam]

I have heard that it times the shifts to be much less stressful on the drivetrain, which to me would mean a much better fit for an e-bike.

Anyone have experience riding with both and care to share if the electronic shift systems are in fact much easier on the drive train on EMTBs?

Thanks!
-Butane

This is not true, Axs does not alter the timing of shift, it just shifts exactly when you tell it to.

I haven't really noticed the problem you mention, not with manual 12 speed shimano or with axs, both on my bosch gen 4 bike.

 

[Jackware]

I posted a similar thread in the Specialized forum but I think this is more of a general question as it can really apply to all EMTBs. I am competent at reducing the torque on my cranks when I downshift on hills on a regular MTB, but I have found it essentially impossible to downshift on a hill with my Levo SL without it feeling really hard on the chain and cassette. I can tell these won't last very long at this rate and I am curious if those of you with electronic shift systems like SRAM AXS still have this problem? I have heard that it times the shifts to be much less stressful on the drivetrain, which to me would mean a much better fit for an e-bike.

Anyone have experience riding with both and care to share if the electronic shift systems are in fact much easier on the drive train on EMTBs?

Thanks!
-Butane

The AXS does make smooth shifts but it's still possible to make clunky hard shifts if you don't lighten or pause momentarily. The app has an option to allow multi-shifts but had a statement that to maintain warranty on ebikes this has to be switched off. Though the system can change gear so quickly it's really not necessary anyway.
Most of the Bosch motors have 'shift detection' that uses the torque sensor to detect the slight change in chain tension to reduce output slightly but on my previous Bosch powered bike I still found it best to lighten peddle pressure slightly to help the system.
On my current PW-X2 Yamaha I lighten off a lot to change, after reading about broken cassettes and chains, but as I think someone has already said, the power/torque available allows you to regain momentum almost immediately.

 

[Jackware]

Although you know how to lighten off to shift gears I think others are trying to say ( though maybe not very diplomatically) you need to learn how your own bike feels.
You know how to drive but you still need to get used to how a different car's brakes and clutch feel.

 

[dobbyhasfriends]

I posted a similar thread in the Specialized forum but I think this is more of a general question as it can really apply to all EMTBs. I am competent at reducing the torque on my cranks when I downshift on hills on a regular MTB, but I have found it essentially impossible to downshift on a hill with my Levo SL without it feeling really hard on the chain and cassette. I can tell these won't last very long at this rate and I am curious if those of you with electronic shift systems like SRAM AXS still have this problem? I have heard that it times the shifts to be much less stressful on the drivetrain, which to me would mean a much better fit for an e-bike.

Anyone have experience riding with both and care to share if the electronic shift systems are in fact much easier on the drive train on EMTBs?

Thanks!
-Butane

dont know if this will help because I've no experience of AXS but, when I bought my first ebike I struggled to get used to the shifting, especially in turbo. I tried the usual things of taking the torque off the pedals when shifting but of course the motor is still 'pedalling' for you. then I tried stopping pedalling altogether and of course, same thing. in the end its like a lot of the other stuff you have to get used to on an ebike, it came down to timing and technique, just like a bunnyhop, I had to make an adjustment to my riding and it pretty much came down to being my fault.

 

[Jimbo Vills]

Guys, please stop suggesting the OP might need to adjust his technique and shifting.

this is ridiculous.

He’s already told his dudes in the other thread he knows perfectly well how to shift his normal bike and it couldn’t possibly be anything to do with him.

it’s the bike. Obviously

 

[Jackware]

Guys, please stop suggesting the OP might need to adjust his technique and shifting.

this is ridiculous.

He’s already told his dudes in the other thread he knows perfectly well how to shift his normal bike and it couldn’t possibly be anything to do with him.

it’s the bike. Obviously

Now Jimmy, play nicely with the new kid in the playground ?

 

[Butane]

Man my dude over here is trying very hard to have an argument online that I care nothing about. We call that a troll on most other forums.

On a more productive note, it's 100% down to a different technique being necessary because of the over-run where the motor continually applies torque after you stop pedaling. I will definitely be adjusting to wait a bit longer until I reapply crank pressure. Btw I have admitted this about 5 times in my previous posts but Jimmy is a virgin with nothing better to do but try to rile up strangers online

 

[Jimbo Vills]

Honestly my dude, try having a read back of your areshole comments (simply because you didn’t want to hear you was potentially at fault ....which you now seem to accept you need to adjust your technique to sort your problem) and maybe you will understand why some people can’t be arsed giving you the time of day ??

 

[Butane]

Id encourage you to do the same. I have definitely been an asshole in some of my posts. However, many people have given me the time of day which has led to an actually civil and productive discussion, which you have essentially not contributed to whatsoever and have actively tried to derail in every one of you posts.

 

[Jimbo Vills]

So my original point saying that I didn’t think the axs would cut power on the motor to stop the pressure on your drive chain (like a quickshifter on a motorbike does but I’m guessing you don’t know what that is) to stop you problem wasn’t relevant?

hmm. Now you seem to realise there is additional over run on your sl to your normal mountain bike. And you need to adjust your technique to suit. Because you was shifting poorly.

But you was rude in your response because at the time you just didn’t want to hear it.

And you wonder why it got peoples back up.

well I apologise for the de railing of the thread to the forum.

but you sir, can do one!

 

[dobbyhasfriends]

get a room you two ?? ?

 

[Zimmerframe]

@dobbyhasfriends 's right .. Come on you two .. lets put this one to bed ..

@Butane's admitted he was an a-hole in some posts.

@Jimbo Vills admitted that @Butane was an a-hole in some posts.

So as far as I can see, you both agree on at least one thing and the other things can be put down to miss understanding, beer, frustration, the complexities of forum postings and the fact that we all can be a-holes some times, I know I can be be pretty good at it. Some days I should probably dress in toilet paper.

Now, lets talk about the wonders of single speed.

 

[B1rdie]

Using shimano E8000 and eletronic rear derailleur the best technic I found is to do a light backpedal before shifting, just an incremental backpedal will imediatelly cut the assistance, unloading the drivetrain.

 

[Butane]

Using shimano E8000 and eletronic rear derailleur the best technic I found is to do a light backpedal before shifting, just an incremental backpedal will imediatelly cut the assistance, unloading the drivetrain.

Nice, I am actually gonna try this today to see if it works on the SL motor. Good advice.

 

[Jon A]

As somebody new to E-Bikes, I'm interested in the technical aspects of this question.

My bike, which should be delivered next month will have shift detection--it will literally cut power to the motor for some fraction of a second when the rider shifts. One question I've had and not really seen discussed anywhere, was if I upgraded to one of the wireless shifting systems, how would the shift detection be incorporated (since the current sensor relies on the cable)?

If I'm surmising the above discussion correctly, there is no way to incorporate it? Do these high end bikes really just let the motor pull on the chain with all their torque while shifting?

 

[Jackware]

As somebody new to E-Bikes, I'm interested in the technical aspects of this question.

My bike, which should be delivered next month will have shift detection--it will literally cut power to the motor for some fraction of a second when the rider shifts. One question I've had and not really seen discussed anywhere, was if I upgraded to one of the wireless shifting systems, how would the shift detection be incorporated (since the current sensor relies on the cable)?

If I'm surmising the above discussion correctly, there is no way to incorporate it? Do these high end bikes really just let the motor pull on the chain with all their torque while shifting?

Yep apart from a couple of systems as mentioned above, which is why @Butane was asking about reducing or stopping his pedalling when shifting.

 

[Mteam]

As somebody new to E-Bikes, I'm interested in the technical aspects of this question.

My bike, which should be delivered next month will have shift detection--it will literally cut power to the motor for some fraction of a second when the rider shifts. One question I've had and not really seen discussed anywhere, was if I upgraded to one of the wireless shifting systems, how would the shift detection be incorporated (since the current sensor relies on the cable)?

If I'm surmising the above discussion correctly, there is no way to incorporate it? Do these high end bikes really just let the motor pull on the chain with all their torque while shifting?

What bike is it that you're getting?

 

[Jon A]

What bike is it that you're getting?

Dengfu E06 with the Bafang Ultra.

 

[Konanige]

I have AXS on my Sl. It doesn't time the shifts at all so I'm not sure where that comes from. Its not in fact the derailleur that does the shifting its the chain and cassette that does that, the derailleur just gives the chain a nudge in the right direction till the cassette picks it up and moves it. The higher spec it is usually means quieter smoother shifting. I can easily soft pedal to change gear on my SL as there is no overrun at all I think the OP may have a motor issue.

 

[michael williams]

I am new to this forum and new to emtb's. I am however, not new to ebikes or electronic shifting. I've used Di2 for several years and found the longevity to be no noticable difference. I bought a Giant trance advanced which came with cable shifting. This bike has no place to put the battery for Di2 that made me happy so I decided to try the axs gx. Got to tell you I am very pleased so far. As for the longevity it is just not that important to me. If it wears out replace it and get back to riding. Life is to short. IMHO

 

[Ark]

Just down shift earlier and learn to spin the cranks.
most efficiency is around 90rpm as far as your legs are concerned, you just need to get used to a high cadence,

too many people stamp the pedals at 60rpm cos they never built up any fitness in their legs, probably the ones who need a new motor every 200km