E-bike Rear Hub Conversion Kits
Rear-wheel mounted hub motors are more common on pre-built bikes because they offer better traction, more control, and are easily installed at the factory. For a conversion kit, they are a little harder to install than a front hub motor because of the chain, gearing and derailleur. Plus, you may be limited to a 6 or 7-speed freewheel. However, a rear hub motor drive will provide more torque and be less obvious than a front hub motor if this is a concern.
Conversion kits include the motorized rear wheel that replaces the bike's rear wheel, a throttle (for Class 2 bikes), and new brakes that will cut power to the motor while braking. Hub motors come in both direct-drive, single speed configuration, and geared models. Direct drives are usually quieter, a bit faster, and more durable. Rear wheel motors can be combined with derailleur shifting, not with hub gears, since these are replace by the motor.