How to install a rear-wheel e-bike conversion kit

As with the front kit, wire it all up first: motor and system cables to the controller, then throttle (yellow), e-brakes (red), the LCD display (green), and the 48V battery. Align any arrowed connectors and push them home, switch on and tap the throttle briefly to confirm the motor responds. Then disconnect ready to mount.

The dropout slot must be 10mm wide (9mm steel can be filed; never carbon/aluminium) with standard 135mm spacing. The manual's ideal dropout depth is 14mm — if the axle spindle sticks proud, you must fit a torque arm. Check whether your bike runs a freewheel (screw-on, compatible) or a cassette (you'll need a separate freewheel). Wheel sizes covered: 27.5" and 700c/28"/29er.

Flip the bike onto its saddle and bars, shift to the smallest sprocket, release the brake and remove the rear wheel. Transfer your tyre, tube, rim tape (and disc rotor, if fitted) onto the motor wheel.

The rear hub only takes a freewheel (threaded cogs). Remove your existing freewheel with a freewheel-remover tool to reuse it, or hand-fit the new one you bought. Clean and grease the threads first, then thread the freewheel on — pedalling pressure self-tightens it.

The motor spindle's flange must not sit below the freewheel edge — if it does (common with 8+ cog freewheels or a rear spacer), "pancake" the supplied washers onto the flange until they clear it, so the dropouts can't rub the freewheel. If your derailleur later rubs the motor on the biggest cogs, add spacers behind the freewheel by trial and error until it shifts cleanly. Spacers aren't included, so start without one.

Guide the chain onto the freewheel and drop the axle into the dropouts with the motor cable correctly oriented. Seat the torque washer's flange into the dropout from the inside, then fit the washers and nuts and tighten firmly.

The 1000W motor makes serious torque, so a torque arm protects weaker dropouts. It is not supplied by default because not every bike needs one — but fit one if your frame is aluminium, carbon or degraded steel, if you filed the dropouts, or if the dropouts aren't deep enough to swallow the spindle. Secure its tab to the chainstay so it braces against motor torque. Never run a high-power rear hub on a frame that needs an arm without one.

Put the chain back over the freewheel and derailleur. With the bike still upside down, spin the pedals by hand, shift through the gears and adjust the derailleur so it reaches every cog without touching the motor (add/adjust spacers if it rubs). Re-check and adjust the brakes.

Fit the pedal-assist sensor to the square-taper bottom-bracket spindle and mount the pickup on the down/seat-tube — see the PAS fitting guide. Skip this step if you'll ride on the throttle.

Bolt the 48V battery holder to the down-tube bosses and slide the battery in. The 1000W controller is larger and may not fit the plastic box, so it often comes with a Velcro bag to mount on the frame — keep the battery bullet connectors inside the housing.

Fit the throttle, e-brakes (optional; not for integrated-shifter or hydraulic levers) and the LCD display on the bars. Reconnect the colour-coded loom (yellow/red/green), route it along the frame and zip-tie it clear of the gear and brake cables.

Switch on, lift the rear wheel and tap the throttle to confirm the motor spins; pedal to check PAS. In the LCD's user setup, set your maximum speed, wheel diameter and units so readings are accurate. The kit is road-restricted out of the box; the LCD is also how you de-restrict it for off-road use only (genuine de-restriction needs Cyclotricity's codes after signing the disclaimer). Re-check the torque arm and axle nuts after your first ride.