Miniwave Bottom Bracket Service and ReplacementUpdated a few seconds ago

The bottom bracket is the bearing unit inside the frame that lets your cranks spin smoothly. Over time the bearings wear, which can cause creaking, clicking or rough pedalling. Even when it isn’t worn, it’s good practice to occasionally remove it, clean the frame shell and refit it with fresh grease, as moisture and dirt work their way in.

The Miniwave uses a standard sealed cartridge bottom bracket (the same type a bike shop stocks), with the cadence (pedal assist) sensor mounted externally on the left side of the spindle.

Tip: This job needs a few bike-specific tools. If you don’t have them, any bike shop can do it — it doesn’t need to be an e-bike specialist.

Tools Required

• Pedal wrench, or a thin 15 mm spanner
• 8 mm hex key (crank bolts)
• Crank puller (square taper type)
• Bottom bracket tool (splined, to suit a cartridge bottom bracket)
• Bike grease
• Paper towel and a zip tie

Step 1 — Remove the Pedals

Turn the bike off and remove the battery first.

• The right (chain side) pedal loosens counter-clockwise.
• The left pedal is reverse-threaded and loosens clockwise.

Step 2 — Remove the Crank Arms

1. Remove both crank bolts with the 8 mm hex key (counter-clockwise).

2. Carefully thread the crank puller into the crank arm by hand until it stops, then give it about 1/8 of a turn more with a spanner. If it feels tight right from the start, stop — forcing it will strip the threads in the crank.
3. Turn the puller’s centre bolt to push the crank arm off the spindle. Repeat on the other side.

Tip: Once the chainring is off, wrap the chain in a paper towel and zip-tie it to the chainstay so it doesn’t scratch the frame.

Step 3 — Remove the Cadence Sensor

Pull the cadence sensor straight off the left side of the spindle. It is held on by friction, so expect some resistance. Don’t lose the small rubber o-ring that sits in the groove inside the sensor.

Step 4 — Remove the Bottom Bracket

1. Remove the left cup first. It loosens counter-clockwise.
2. Remove the right (chain side) body. It is reverse-threaded and loosens clockwise.

3. Clean all dirt and old grease out of the frame shell. Take care with your fingers, as small metal shavings from manufacturing are sometimes left inside.

Step 5 — Reinstall

1. Apply a thin layer of grease to the threads in the frame shell and on the bottom bracket.
2. Thread the right (chain side) body in by hand first (it tightens counter-clockwise), then tighten firmly with the tool.
3. Thread the left cup in by hand (it tightens clockwise), then tighten firmly. If your bottom bracket lists a torque value, tighten to that figure.
4. Check the o-ring is in place, then push the cadence sensor back onto the left side of the spindle with its cable routed the same way as before.
5. Refit the crank arms, making sure they point in opposite directions (180° apart). Tighten the crank bolts to 39 Nm.
6. Grease the pedal threads and refit the pedals by hand first, right pedal on the right, left pedal on the left, then tighten with the pedal wrench.
7. Refit the battery, turn the bike on and check that pedal assist starts normally when you pedal.

If pedal assist doesn’t work afterwards, check the cadence sensor is fully seated and its cable is connected. A sensor fault may show as error code 22 — see Miniwave Display Error Codes.

Need Help?

If you’re unsure about any step, contact Ridewave Support or visit a qualified bicycle technician.