If your e-bike is powered by a Bosch motor, it's essential to regularly check and maintain the crank arm bolts. These bolts secure the crank arms to the motor spindle and, if left loose, can cause wear, noise, and even crank or motor damage.
Loose crank bolts can lead to:
๐ Creaking or clicking noises during pedalling
๐ฉ Wobbling or movement in the crank arm
โ Long-term damage to crank arms or the motor axle spline
๐ธ Costly repairs if ignored
To prevent this, we recommend making crank bolt checks part of your routine maintenance.
We recommend the following inspection frequency:
๐ข Before every ride (ideal)
๐ก At minimum: After every wash or wet ride
๐ง After any service involving crank removal
Moisture, vibration, and regular use can all cause bolts to loosen over time.
Torque specification: 40 Nm (Newton-metres)
Tool required: A calibrated torque wrench with a 8mm Allen key head
โ ๏ธ Do not overtighten or use uncalibrated tools, as this may damage the crank or spindle interface.
Position the crank arm horizontally (3 o'clock or 9 o'clock)
Insert an 8mm Allen key into the crank bolt
Use a torque wrench to tighten to 40 Nm
Check both crank arms to ensure even torque
If you donโt have access to a torque wrench, book a service with our workshop teamโweโre happy to help.
Not sure how to check torque? We can check and re-torque your cranks as part of any service booking.
๐ Click here to book a service with our workshop
If you're hearing clicking, creaking, or feeling movement in your crank area, donโt keep ridingโget it checked early to avoid more serious damage.
Let us know if you'd like help with your next crank check or need torque tools for home useโweโre here to support your ride.