Step 5 - Install the motor wheel and finish up
In this step we mount the finished motor wheel on the bike and connect all cables.
Overview
┌────────────────────────────────────────────────────┐
│ 5.1 Loosen the brake caliper screws │
│ 5.2 Mount the motor wheel in the frame │
│ 5.3 Adjust with washers if needed │
│ 5.4 Mount the torque arm │
│ 5.5 Tighten and secure the wheel │
│ 5.6 Turn the bike and tighten the brake caliper │
│ 5.7 Connect all cables │
│ 5.8 Zip-tie and tidy the cables │
└────────────────────────────────────────────────────┘
Estimated time: 30 to 45 minutes
Step 5.1 - Loosen the brake caliper screws
Before the motor wheel can be mounted, the brake caliper needs to be able to move.
- Locate the brake caliper - it sits on the frame at the rear wheel mount
- Loosen the screws that hold the brake caliper - only loosen them, do not unscrew them completely!
- The brake caliper should now be able to move sideways
The brake disc on the motor wheel may sit slightly differently from the original wheel. Letting the caliper float allows it to center correctly.
Step 5.2 - Mount the motor wheel in the frame
Test fit
First do a test fit without tightening anything:
- Hold the rear derailleur out of the way with one hand
- Guide the motor wheel down into the rear wheel dropouts of the frame
- Let the chain settle on the smallest sprocket of the freewheel
- Push the wheel fully into the slots
Check the fit
Spin the wheel and check:
| Check point | OK | Problem |
|---|---|---|
| Wheel spins | Slight resistance, normal for motor | Brake rubs, wheel stops |
| Freewheel | Clear of the frame | Hits the frame |
| Brake disc | Centered in the brake caliper | Rubbing on one side |
The motor wheel will not spin as freely as your old rear wheel. The motor creates a slight magnetic resistance. This is normal.
Step 5.3 - Adjust with washers if needed
If the wheel does not fit perfectly, you need to use spacers.
If the brake disc is not centered
The brake rubs on the side nearest the frame:
- Add a washer inside the frame on the brake disc side
- This pushes the wheel outward
If the freewheel hits the frame
- Add a washer inside the frame on the freewheel side
- This shifts the wheel toward the brake side
Try and adjust
- Remove the wheel again
- Choose suitable washers from the ones included in the kit
- Place the washers on the axle on the correct side
- Mount the wheel again - you may need to spread the frame a few mm
- Check the fit again
- Repeat until the wheel spins freely and the brake disc is centered
Step 5.4 - Mount the torque arm
The torque arm prevents the motor torque from rotating the axle in the frame. This is critical for safety!
Mount on one side
- Install the bronze-colored washer with the tab, tab facing inward toward the wheel
- Place the cog-shaped washer on top of the bronze-colored one
- Install the arm part of the torque arm at an angle that:
- Points toward the frame
- Allows a hose clamp to be tightened against the frame tube
- Creates a counter torque against the motor force
The torque arm should point in the direction that makes the hose clamp hold back when the motor tries to twist the axle. Think of it as braking against the motor - the arm should then press against the frame.
If the arm sits crooked
If the arm part does not sit flat against the washers:
- Add a bronze-colored washer without a tab under the cog-shaped washer
- Thread on the wheel axle nut finger tight to hold the parts in place
Repeat on the other side
Do steps 1 to 4 on the other side of the wheel.
Step 5.5 - Tighten and secure the wheel
Attach the torque arms
- Install hose clamps on both torque arms
- Place the clamps around the frame tubes
- Tighten the hose clamps until they sit firmly
- Do NOT tighten so hard that the axle starts to turn
Tighten the axle nuts
- Use two 21 mm wrenches - one on each side
- Tighten both sides at the same time if possible
- Tighten firmly - the nuts must sit very tight
- Check that the wheel still spins freely
Loose axle nuts can cause the wheel to come off while riding. Double-check that they are properly tightened!
Final wheel and brake check
- Spin the wheel - it should rotate freely
- Listen - the brake should not scrape against the disc
- Look at the gap between the brake pads and the disc - is it even on both sides?
Step 5.6 - Turn the bike and tighten the brake caliper
Turn the bike upright
- Lift the bike carefully
- Turn it so the wheels are on the ground
- Set it down securely with the stand or against a wall
Center and lock the brake caliper
- Pull the brake lever and hold it in
- While the brake is engaged, tighten the brake caliper screws
- Release the brake lever
- Test - spin the wheel and check that the brake does not rub
By tightening the screws while the brake is engaged, the brake caliper centers itself automatically around the disc.
Step 5.7 - Connect all cables
Now all electrical connections will be made.
Cable overview
| Cable | From | To controller port |
|---|---|---|
| Red power cable | Battery plate | B+ |
| Black power cable | Battery plate | B- |
| Phase wires (3) | Motor | Motor output |
| Hall cable | Motor | Hall sensor |
| Throttle | Handlebar | Throttle port |
| Ignition | Handlebar | Ignition port |
Connect the power cables
- Locate the cables from the battery plate
- Connect the red cable to B+ on the controller
- Connect the black cable to B- on the controller
Never switch the red and black cables! Incorrect polarity can destroy the controller and battery.
Connect the phase wires
- Locate the three phase wires from the motor, usually yellow, blue, and green
- Connect them to the matching ports on the controller
- Make sure the connectors are fully seated
Connect the Hall cable
- Locate the Hall cable from the motor, a smaller connector, often with several thin wires
- Connect it to the Hall sensor port on the controller
- The connector only fits one way - do not force it
Connect the throttle and ignition
- Route the throttle cable to the controller
- Connect it to the throttle port
- Connect the ignition cable, if present, to the ignition port
Step 5.8 - Zip-tie and tidy the cables
A neat and safe cable run prevents problems.
Route the cables neatly
- Gather cables that run the same route
- Avoid sharp bends that could damage the cables
- Leave slack at moving parts, handlebar and rear derailleur
Secure with zip ties
- Use zip ties to attach cables to the frame
- Place zip ties at even intervals
- Tighten them just enough - not so much that the cables are pinched
- Clip off excess ends with side cutters
Check the cable routing
- No cables are hanging loose
- No cables can get caught in the wheel or chain
- Enough slack at the handlebars for full rotation
- No pinch points
Checklist
After this step you should have:
- The motor wheel mounted and centered
- Torque arms mounted and secured with hose clamps
- Axle nuts properly tightened
- Brake caliper centered and locked
- All electrical connections made
- Cables neatly routed and zip-tied
Common problems
The brake still rubs even though the screws are loose
- Add a washer inside the frame on the brake disc side
- Remove the wheel and repeat the installation
The torque arm does not fit
- Try a different angle
- Check that all washers are in the correct order
The cables are too short
- Move the controller to a better position
- Contact support for extension cables
The connectors do not fit
- Check that you have the correct connector for the correct port
- Never force them - the connectors should slide in easily
➡️ Next step: Testing