The geared hub motor has a clutch inside which engages the motor when motorized. The geared hub motor also has free wheels for when the motor is not providing a torque. The brushless geared hub motor does not have any drag when used as a normal bike; ...
The best choice is to have the mass of the motor attached to the bike’s frame for higher wheel maneuverability, especially for mountain biking and full-suspension bikes. These motors are typically more complex and heavier due to the required ...