This is just a cautionary tale. I started to install my new BBS02 motor on my Cannondale Quick5 street bike. The bottom bracket shell is a fraction of a millimeter smaller in diameter than the motor shaft, so it just won't fit. I am not sure if I could have avoided this problem with more diligent research. Do bike manufacturers provide specs for the size of that bottom bracket hole. Does Bafang provide diameter of shaft info? In any case I guess my Cannondale is too "special" so I will search for a descent second hand mountain bike and try to mount the motor on it.