You are all probably aware of the service repair kit Bosch released recently. Designed to replace all the bearings and plastic gears on the right-hand side of the motor. What we have found is these bearings usually fail due to water ingress. The problem is, water also gets in through the left-hand crankshaft bearing too! This obviously damages the bearing and then gets spun out by the crankshaft gear and can damage the transfer gear bearings.

Also, any water coming past the right-hand crankshaft bearing can destroy the freewheel gear bearing.

 

So, for people and shops that want to do the job properly, we now have a kit available that includes The genuine Bosch service kit and all the bearings required to do the full job! https://www.performancelinebearings.com/product/bosch-motor-service-repair-kit/

 

Below are some typical examples I see on a regular basis.

 

Is the Yamaha motor equally afflicted by water ingress?

Is the Yamaha motor equally afflicted by water ingress?

Yes. The balls inside the bearing are a little larger and less of them, so the bearing takes a little longer to fail completely, but they do fail.

Hi

Is your fitting price Inc vat or plus

Thanks

Hi

Is your fitting price Inc vat or plus

Thanks

All prices include VAT. Sorry, I will amend my site to make it clearer.

All prices include VAT. Sorry, I will amend my site to make it clearer.

Nice one

Keep up the good work

Thanks Pete! I got new 160mm cranks for the KTM today and decided to see how the Bosch "Green grease" was faring behind the RHS crank....well, apart from some expected dirt and pine needles around the outer edge it's still really clean and still forming a superb barrier to the crankshaft bearing behind it. It's had a fair few manky dirty/wet outings here in the Cairngorms so looks to be good stuff....(just need to find a cheaper copy lol!!)

Thanks Pete! I got new 160mm cranks for the KTM today and decided to see how the Bosch "Green grease" was faring behind the RHS crank....well, apart from some expected dirt and pine needles around the outer edge it's still really clean and still forming a superb barrier to the crankshaft bearing behind it. It's had a fair few manky dirty/wet outings here in the Cairngorms so looks to be good stuff....(just need to find a cheaper copy lol!!)

Excellent feedback, thank you Barrio. I have found a very similar grease now and there is 100ml in the tube rather than the 20ml from Bosch. I am doing some tests to ensure it is as good if not better and if I'm happy, then it will be on the site soon.

! I got new 160mm cranks for the KTM today

 

dealers can now change the crank length in the diagnostics software for the motor tho i cant see what 5mm difference will make tbh but the option is there.

I'm still not sure why that's needed- Gone from 170 to 160mm. Smaller cranks actually raise the gearing (https://www.momnium.com/impact-crank-length-gear-ratios/)- I'll just have to try it but really don't know if it will be that noticeable?? But the little bit extra ground clearance will be welcome through rutted, boulder strewn single tracks, if I don't like them I'll put the EX1's back on but at least have a spare pair in case of any mishaps...

I'm still not sure why that's needed- Gone from 170 to 160mm. Smaller cranks actually raise the gearing (https://www.momnium.com/impact-crank-length-gear-ratios/)- I'll just have to try it but really don't know if it will be that noticeable?? But the little bit extra ground clearance will be welcome through rutted, boulder strewn single tracks, if I don't like them I'll put the EX1's back on but at least have a spare pair in case of any mishaps...

my lbs will do it for £45

Found it.....

New Update For Short eMTB Crank Arms

Most riders run regular length cranks (170-175mm) but on an eMTB you tend to tackle harder climbs and the electric mountain bike allows you to navigate up rocks/obstacles etc.

With full-length cranks, pedal strikes become more apparent. This means many riders have been fitting short Bosch eBike crank arms (165-150mm) which allows more ground clearance for more adventurous riding.

 

The trouble with just swapping the cranks is that it alters the feedback the drive system gets. Which in turn alters the output of the motor assistance feel, torque curve and in particular the characteristics when in eMTB mode.

 

For 2019 Bosch introduces software updates via a Bosch eBike dealer, who can program each bike to suit the preferred crank length. This adapts the progression curve in eMTB mode and also offers increased support in Tour mode, offering maximum power up-hill.

 

My bike doesn't have the "automatic" gearbox which I prefer. I'd rather be in control over how much juice is used from the battery and how much I input, or else this system may just keep assisting when I really don't want it to?? I might speak to the LBS we deal with at work, see what they say about it...