Originally Posted by
Kimmo
Most issues with cartridge bearings on bikes are due to contamination. Usually not much of a consideration for electric motors.
Yeah. I suppose that is the most likely explanation, although that doesn’t speak very well of the seals since I dont ride much in rain and in both cases, when I removed the seals, the balls and grease looked pristine. In both cases, one ball just was immobile, like it popped out of the grrove,something grit getting behind the seal could cause.