I have a sunrunner ebike that I recently bought 2nd hand. I loosened the axle nuts to move the wheel back to allow me access to the roller brake grease port then tightened it all back up. When pedaling I felt the hub slip so checked and it had rotated.
The bike doesn't have any anti rotation washers and seems to just rely on the grip of the washer to the frame (axle nuts were incredibly tight before I started work on it). I assumed the drive side had a silver nexus anti rotation washer but it's just some silver flat washer.
Can someone confirm I need a 6L and/or 6R washer?
Dropouts are 10mm wide, axle flats are 8mm, it has what looks like a lock washer with 17mm flats that actually sits inside the dropouts.
