Bafang M635 Torque Sensing Motor Pedal problem

[Moonboy6901]

Hey all, I got a Bafang torque sensing motor put on my bike including a throttle. I work on Mackinac island so I use it everyday for commuting or for hitting trails and it has given me no problems other than a clicking sound coming from the bottom bracket area when I pedal. But now I must’ve rode it too hard because when I try and pedal now they kind of slip and I can’t continually pedal without them slipping. Any idea what could be wrong with it?

 

[Mongo]

If throttling alone powers the bike just fine, I would pull the motor's secondary gear and examine the spindle clutch for broken teeth (clutch pawls or the related gear) or perhaps the clutch pawl spring. The clutch nestles down within the center of the secondary reduction gear:

Spindle clutch:


Secondary reduction gear:


There's a how-to video on the subject for the Bafang BBSHD motor, which, for this issue, the process is likely very similar. Some of the tools required are 1.) a $10 bicycle pedal crank arm puller and 2.) some metric hex wrenches.

For the BBSHD, both the clutch and the secondary gear are commonly available via several U.S.-based resellers. I'd ask the vendor before purchasing if the parts are compatible with the M635 motor (I suspect they are).