Shimano E6100 clutch slip/jerk when engaging (maybe)
 

Hi there



I recently bought my first e-bike, and it is an absolute joy! The bike is a BMC Alpenchallenge AMP with internally geared hub and a Shimano Steps E6100 (with gates carbon drive) – perfect for my use in all aspects.

Unfortunately there is a small thing that wonders me and it has become a small nuisance, so I was hoping someone in this forum can tell me if something is wrong with my bike or not.

Whenever the motor engages (starts providing assistance), I feel a jerk in the crank – as if a clutch or a one-way bearing is slipping a bit. If I let the bike roll and start pedaling again, I feel this small jerk, and it is also present when I start from zero. If I ride without assistance there is no jerk at all, so my conclusion is that it must come from the motor.

Is that normal or could something be wrong?

I didn’t feel the jerk in the beginning, so either I didn’t notice it for the first 2 weeks or it has started this behavior today. Normally I am very aware of such things, so my best guess is that it was not there in the beginning, but of course I might just have been enjoying the bike and not paying attention to how the motor feels when engaging.



Thanks in advance! 😊

The 6100 motor isn't one of the best feelings on the motor but it shouldn't jerk you might get a little extra power as you put on the pedals but it wouldn't be a jerk just the normal acceleration. If it is doing it only when you have assist on it is probably just the assist kicking in but if not then you may consider bringing it back to the shop you purchased from. At least where I work we offer two free tune ups in the first 50-100 miles or so and then usually at the year mark.

Thanks for the info. Well, since the bike was hard to get, I had to order it from Germany (I live en Denmark), so bringing it back is hard (it's not "not an option", just quite a drive), but I can ask them about it - perhaps we can at least share the cost of the first tune-up.
I feel a quite distinct jerk in addition to the added power, and when I come to think of it, it began exactly after my third charge - before the charge I have no recollection of a the jerks, while I noticed them immediately after the third charge.
Don't know if that can tell someone that it might just software related? I did no update during the charging, so the change would then have to be from the charging, which seems unlikely though...

Ahhh...fair enough, there has got to be a shop in Denmark though who can work on Shimano??? Most of the firmware updates would be done at a shop, I haven't done too many STePS bikes but I don't think you can upgrade through your e-tube app unless things have changed massively and nobody mentioned it.

Yes, there is a shop nearby actually, but if it was something I could just easily tighten myself, it would be a swift solution (and their mechanic is actually on vacation now).
The German shop (where I bought the bike) will help as much as they can, and they will see if their Shimano expert has seen this issue before - at least they might know where to look.

Seems like the issue is a bit worse today - feels a bit like steering wheel backlash on and old car :-(

That is an odd one I haven't heard of anything like that I know a motor can feel disengaged and usually that is Brose and that is because the belt has finally broken. Hopefully someone can get to the bottom of it. I would say bring it by my shop and we can fix it but we are much much much farther from Germany and would require a nice boat trip "across the pond" as they would say in England.

Thanks for the offer :thumb: I'll see if somebody just a bit closer can fix it - it least to begin with :lol: