The motor is very hard to turn over by hand. i have checked everything and there is no binding on the rotor. just strong magnets.
i beleieve the bearings are something like 5x13 or 5x14, look like they should be wheel bearings
Both endbells are removable, and yes the little plastic ring is a lifesaver
I have the 1515 1y. great motor, beats the crap out of my 8xl...

(to be expected) but wow soo much power. after 40 minutes of running geared for about 50mph the motor was at 152, but only because i had it geared up (freind lost my 13t pinion)
Thing is a torque monster..