Motors
Used electric bike motors cover front hub, rear hub and mid-drive systems, in both new and second-hand condition. Cranxs connects you with sellers offering units from Bosch, Shimano, Bafang and Yamaha, so you can replace a worn-out motor or add torque for steeper climbs and city commutes.
Hub motor or mid-drive?
Front and rear hub motors sit in the wheel and drive it directly, which keeps installation simple and leaves your existing drivetrain alone. Mid-drive motors sit at the bottom bracket and put power through the chain, so they use your gears on climbs and generally cope better with steep, loaded riding.
Will a used motor fit my e-bike?
Bosch, Shimano and Yamaha mid-drives bolt to frame mounts designed for that specific system, and their connectors and firmware rarely mix across generations, so match the motor to the frame it came from. Bafang units are more open, which is why they turn up so often in conversion kits built around standard 68–73mm threaded bottom bracket shells.
What should I check buying used?
Spin the motor by hand and listen for dry bearings or grinding, then check the cable exit and connector pins for corrosion and water ingress. Ask the seller for the odometer reading and any stored error codes, and on a mid-drive, feel for play at the bottom bracket.
Do I need a matching controller and display?
A motor on its own is only part of the system: it needs a controller speaking the same protocol and, on most builds, a screen to set assist levels. Sellers often list units complete with looms, so check what is included before buying a display separately.
What power is road legal in the UK?
An electric bike counts as an EAPC if the motor is rated at 250W continuous or less, assistance cuts out at 15.5mph and the rider is 14 or over. Anything more powerful is legally a moped and needs registration, tax and insurance, so keep that in mind as you build up the rest of your electric components.