Bafang BBS02B 750W Mid-Drive Kit

Mid-drive systems place weight low and central, which helps balance, and they use the gears to stay efficient on climbs. Kits generally include the motor, a controller, a display, a throttle or sensor, a chainring, cabling and fitting hardware, though contents differ between sellers. Closest alternatives by price: Bafang BBS02B 48V 750W Mid-Drive Conversion Kit ($849), Bafang BBSHD 1000W Mid-Drive Kit ($899) and Bafang BBSHD 48V 1000W Mid-Drive Conversion Kit ($1,150).

Tinkerers who are comfortable removing cranks and bottom brackets will find fitting more manageable than a first-time home mechanic would. Regulations for powered bicycles differ between states, so contact the state road authority about allowable power and whether a modified bike needs registration.

Bafang has 4 products listed, from $699 to $1,150.