WARNING! To Bosch powered ebike owners (pre 2020)

[maker]

yikes, I really hope you're wrong. Just emailed Bosch about this.

OK, good to know about the Mudstop thank you.

I had third motor about 14 months ago and shop said 2 year warranty then.

 

[SupasafeElectroLumberjack]

I had third motor about 14 months ago and shop said 2 year warranty then.

?

 

[Beekeeper]

Nope! And the latest Yamaha motor (Same motor in the Giant), specifically designed for eMTB's, the PW-X and X2 are the worst of all Yamaha motors... Very odd?

What sort of damage would a nasty pedal strike do to the Bosch Gen 2? I’m guessing the main motor bearing could be crushed but maybe left side bearing depending on which pedal was struck.

Any other parts that could suffer?

 

[Bearing Man]

What sort of damage would a nasty pedal strike do to the Bosch Gen 2? I’m guessing the main motor bearing could be crushed but maybe left side bearing depending on which pedal was struck.

Any other parts that could suffer?

A hard pedal strike on a Bosch usually does this. But no bearing damage that I have ever seen.

 

[Beekeeper]

A hard pedal strike on a Bosch usually does this. But no bearing damage that I have ever seen.

View attachment 62418

View attachment 62419

View attachment 62420

Wow! Perhaps Bosch should supply special pedals and cranks which are designed to snap and save the motor.

maybe in packs of 5 like their seals and circlips ?

 

[Bearing Man]

Pedal strikes are not good for ebike motors, they strip the Yamaha drive gears, snap the Brose crankshafts and shatter the sprag bearings, snap the belt tensioners, strip the Shimano drive gears etc.

 

[Stihldog]

Thanks Bearing Man for all your info. ?

2 days ago I had a nasty peddle strike on the drive side which flipped me and the bike over. After I dusted myself off (was avoiding an audience of 12-15 hikers) I was worried that something on the drive side could be bent. (Peddle, crank, shaft). My Kiox was tethered so that was easy to replace. When I finally rode away I never sensed any changes in rotation or sound. After almost 7k km my Bosch gen4 it’s very quiet. I have two other Bosch gen4 (under 500km) that are a bit noisier but I assume they may not be broken-in yet. Is that possible?
Again, thanks for the info. Much appreciated.

 

[Stihldog]

Wow! Perhaps Bosch should supply special pedals and cranks which are designed to snap and save the motor.

maybe in packs of 5 like their seals and circlips ?

I think I would need a pac of 50…?

 

[Bearing Man]

I have two other Bosch gen4 (under 500km) that are a bit noisier but I assume they may not be broken-in yet. Is that possible?
Again, thanks for the info. Much appreciated.

Basically motors of all makes are mass produced units and as such they do tend to vary a bit in noise level.

 

[rod9301]

I tried to read this post but pretty long.

Would i need the steaks for a bosch 2018 motor?

 

[Zimmerframe]

I tried to read this post but pretty long.

Unfortunately a whole thread can't be reduced down to a bumper sticker.

Lucky for you though, this ones only partly on page 2 ! So it's not really much of a read and think of all you'd learn on the way - there are pretty pictures too, well, I liked them.

Would i need the steaks

I think @Bearing Man said he was open to being bribed with beer or sweets - we haven't confirmed if he'd also accept steaks. If it helps, I would and if necessary I could take the steaks and send him some sweets, he's not having my beer.

bosch 2018 motor?

This isn't really 100% useful. You're kind of sitting back and letting someone else do all the work for you without giving any information. Bosch make several motors. For instance, is it in a mountain bike ? Does it have a tiny chainring which looks like you could keep a spare in your wallet ? In which case it's most likely a Bosch Gen2 Motor. The newer version for MTB is the Gen4 motor. To confuse things, the Gen3 motor was more for shopping bikes and similar.

 

[Beekeeper]

Bearing Man’s comments are the best reads of all. Should definitely be made into a book ? ?
And there would be pictures too

actually could also be released as a horror movie ? ?

 

[nandewar]

Thanks for the heads up on this. I'm a little confused though. I have a 2018 Trek Powerfly with the Performance CX. Not sure what Gen but am assuming 2 as it has the tiny front sprocket. It was mentioned earlier that Bosch introduced the felt seal post 2019. What do I use on my 2018 motor as it has done 7600km and could do with some preventive maintenance? Thanks in advance.

 

[Bearing Man]

Thanks for the heads up on this. I'm a little confused though. I have a 2018 Trek Powerfly with the Performance CX. Not sure what Gen but am assuming 2 as it has the tiny front sprocket. It was mentioned earlier that Bosch introduced the felt seal post 2019. What do I use on my 2018 motor as it has done 7600km and could do with some preventive maintenance? Thanks in advance.

Your motor will currently have no protection and is relying on the dust seals fitted to the actual bearing. If you're just using your bike on road, this will be fine, but if you ride off road, you really should think about protecting this bearing with the crankshaft seal.

 

[SupasafeElectroLumberjack]

They used to come with a rolling 2 year warranty but I believe this is now been stopped.

The MudStop does the same, you remove the original Bosch seal and replace it with the MudStop, this was sanctioned by Bosch and has definitely never affected anyone's warranty that I am aware of.

Heard from Bosch- apparently there was never a rolling 2 month warranty, however the motors were replaced as a gesture of goodwill.

Here's hoping I remain in their good books

 

[TheRealPoMo]

Installed the crank seal and Mudstop today on my 2019 gen 2. Local Aussie distributor was good to deal with after initial confusion about part numbers. Crank had some fine dust behind the circlip but the bearing face looked fair. Seal took some urging to locate with some taps with a rubber mallet. Old seat post made an excellent drift. There seems a bit more resistance now when cranking on the stand but I assume its the seal and more so the Mudstop which appears to get loaded up with the chainring guard/nut and bears on the case... assuming I did it correctly....that sound ok @Bearing Man ?

Just to head off any confusion for those undertaking this, the picture is before the crank seal and Mudstop were installed. No felt washer and old Bosch plastic ring seal still in place.

 

[Bearing Man]

Installed the crank seal and Mudstop today on my 2019 gen 2. Local Aussie distributor was good to deal with after initial confusion about part numbers. Crank had some fine dust behind the circlip but the bearing face looked fair. Seal took some urging to locate with some taps with a rubber mallet. Old seat post made an excellent drift. There seems a bit more resistance now when cranking on the stand but I assume its the seal and more so the Mudstop which appears to get loaded up with the chainring guard/nut and bears on the case... assuming I did it correctly....that sound ok @Bearing Man ? View attachment 64186
Just to head off any confusion for those undertaking this, the picture is before the crank seal and Mudstop were installed. No felt washer and old Bosch plastic ring seal still in place.

Sounds ominous this. The seal should slide on relatively easily with a bit of grease and using the wire from the kit to let the air out from behind it.
The MudStop should slide on and not be compressed by the sprocket nut. You did cut your cover away to allow room for it didn't you?

 

[TheRealPoMo]

Sounds ominous this. The seal should slide on relatively easily with a bit of grease and using the wire from the kit to let the air out from behind it.
The MudStop should slide on and not be compressed by the sprocket nut. You did cut your cover away to allow room for it didn't you?

Thanks @Bearing Man .
Yeah the seal was tighter than I expected, but I used the wire - I don't what else could be wrong. it's definately in the right way.
By "cover", you mean the old Bosch bearing cover referred to in the instructions? Yes that came off.
There is a narrow spacer with the chainring (below - and yes I think that is one of your pictures) - I wonder if I have that on the wrong way. Looks like it's supposed to go on the motor side from a google or 2. I'll recheck.

Cheers

 

[TheRealPoMo]

Thanks @Bearing Man .
Yeah the seal was tighter than I expected, but I used the wire - I don't what else could be wrong. it's definately in the right way.
By "cover", you mean the old Bosch bearing cover referred to in the instructions? Yes that came off.
There is a narrow spacer with the chainring (below - and yes I think that is one of your pictures) - I wonder if I have that on the wrong way. Looks like it's supposed to go on the motor side from a google or 2. I'll recheck.

Cheers
View attachment 64295

Yep, OK - got it now.
It is riding on the actual outer cover - I see now this is not the way it's supposed to be - and looks bleedin' obvious in hindsight.
I'll have to cut clearance in the motor cover to accomodate.
Cheers

 

[Bearing Man]

Yep, OK - got it now.
It is riding on the actual outer cover - I see now this is not the way it's supposed to be - and looks bleedin' obvious in hindsight.
I'll have to cut clearance in the motor cover to accomodate.
Cheers

 

[deksawyer]

I've fitted 2 mudstops to 2 boch motors and never cut anything away.....

 

[Bearing Man]

I've fitted 2 mudstops to 2 boch motors and never cut anything away.....

Depends on the bike, some have covers and some don't, but if there is a plastic cover there, it should be opened up by 1.5mm to accept the MudStop without rubbing.

 

[deksawyer]

Depends on the bike, some have covers and some don't, but if there is a plastic cover there, it should be opened up by 1.5mm to accept the MudStop without rubbing.

Thanks Pete

it's a Haibike and I'm pretty sure I would've noticed something like that....

 

[Daev]

Yes, you can find out all about an alternate seal here: Rotary shaft seal for Bosch And yes it's relatively easy to fit. Below are the instructions for both seal and MudStop.
These are external parts and will not affect any warranty. Not that there are many Gen 2's still in warranty.

Awesome - just ordered both for my 2nd hand Trek Powerfly 9.7 with a mere 350 miles on the clock of the Gen 2 Performance Line CX - after all a bit of preventative maintenance goes a long way (hopefully). I'm not as OCD as perhaps I should be about the cleaning, and certainly not as much as the previous owner - it is verrrry clean though, bless 'im.
Thanks for being there and thanks for knowing what you are doing - I'll let y'all know how it goes when done.
(hopefully I've ordered all that I need to get the job done in one go)

 

[Sander23]

Oh boy, I just fitted the service kit with this felt seal on my gen 2.
So it's better to not fot it @Bearing Man

I fitted some of that green tacky grease from bosch behind it then put the seal and again a layer of that tacky grease.
Had no idea how to fit it as there is no manual instructions on how to.

 

[Bearing Man]

Oh boy, I just fitted the service kit with this felt seal on my gen 2.
So it's better to not fit it @Bearing Man

All I can tell you is, we are seeing ever more damage being caused by this felt sponge. Far worse damage than most motors we see with no felt. I can only recommend that if you use your bike off-road, ditch the felt and fit our custom made double lip rotary shaft seal which definitely is 100% watertight. BOSCH CRANKSHAFT SEAL

 

[Sander23]

All I can tell you is, we are seeing ever more damage being caused by this felt sponge. Far worse damage than most motors we see with no felt. I can only recommend that if you use your bike off-road, ditch the felt and fit our custom made double lip rotary shaft seal which definitely is 100% watertight. BOSCH CRANKSHAFT SEAL

You have Any other supplier in Europe?
Import duty to belgium is cost alot more then the cost of that seal

 

[Bearing Man]

You have Any other supplier in Europe?
Import duty to belgium is cost alot more then the cost of that seal

You can buy these parts from any of our suppliers here: Worldwide partners

 

[Daev]

Arrived today - faster than Amazon

 

[Bearing Man]

Awesome - just ordered both for my 2nd hand Trek Powerfly 9.7 with a mere 350 miles on the clock of the Gen 2 Performance Line CX - after all a bit of preventative maintenance goes a long way (hopefully). I'm not as OCD as perhaps I should be about the cleaning, and certainly not as much as the previous owner - it is verrrry clean though, bless 'im.
Thanks for being there and thanks for knowing what you are doing - I'll let y'all know how it goes when done.
(hopefully I've ordered all that I need to get the job done in one go)

Just check our Facebook page and scroll down to the Trek post. Not sure if the cover we speak about is fitted to your model but if it's you may want to read this post or you will be changing bearings every week!