[johnrobholmes]

My vote would be that the stator is skewed as well. Magnetic detents (cogging as you are calling it) are determined by the magnetic pole/ stator count ratio as well as the magnet strength and motor design. I doubt that Neu went slotless, so the most likely choice is that they skewed the stator laminations. It shouldn't actually effect the efficiency, but it will make the motor roll easier and put less vibration through the vehicle.