Hi everyone,
I'm looking for some advice before I spend more money on parts or send my motor to a Brose repair service.
I have a 2020 S-Works Turbo Levo. During a ride, the bike suddenly stopped providing assistance. Just before it died, I heard a strange noise coming from the motor for about 10 seconds. After that there was no power, and the motor status LED turned red. The bike is long out of warranty, so I decided to investigate myself. I carefully opened the motor and found that the drive belt had completely disintegrated. There was belt debris everywhere inside the motor. I cleaned everything thoroughly by hand and with compressed air, then ordered a replacement belt.
While waiting for the belt, I learned that there's a good chance the tension pulley should also be replaced, and that the pulley adjustment requires a very low-range torque wrench (around 0.2 Nm) to set the belt tension correctly. Impatient to get the bike running again, I replaced only the belt and tightened the tensioner screw by feel rather than using the proper torque setting.
After reassembling and reinstalling the motor, I ran into a new problem:
After doing some more research, I found two possible explanations:
Before I start buying more parts (tension pulley, special torque wrench, etc.), I'd like to know if there are any tests, diagnostics, or checks I can perform myself to narrow down the cause.
Has anyone experienced similar symptoms after a belt replacement on a Brose motor? Does this behavior sound more like a belt tension issue or a torque sensor problem or anything else?
Any advice would be greatly appreciated. Thanks!
I'm looking for some advice before I spend more money on parts or send my motor to a Brose repair service.
I have a 2020 S-Works Turbo Levo. During a ride, the bike suddenly stopped providing assistance. Just before it died, I heard a strange noise coming from the motor for about 10 seconds. After that there was no power, and the motor status LED turned red. The bike is long out of warranty, so I decided to investigate myself. I carefully opened the motor and found that the drive belt had completely disintegrated. There was belt debris everywhere inside the motor. I cleaned everything thoroughly by hand and with compressed air, then ordered a replacement belt.
While waiting for the belt, I learned that there's a good chance the tension pulley should also be replaced, and that the pulley adjustment requires a very low-range torque wrench (around 0.2 Nm) to set the belt tension correctly. Impatient to get the bike running again, I replaced only the belt and tightened the tensioner screw by feel rather than using the proper torque setting.
After reassembling and reinstalling the motor, I ran into a new problem:
- When I turn the bike on, the motor immediately starts driving by itself.
- The cranks rotate slowly without me touching the pedals.
- If I apply the brake, the cranks stop.
- As soon as I release the brake, they start turning again.
After doing some more research, I found two possible explanations:
- The belt tension is incorrect, causing the motor/torque sensing system to think there is constant pedal pressure.
- The torque sensor was somehow damaged or affected by the belt failure, debris, or cleaning process, and is now giving incorrect readings.
Before I start buying more parts (tension pulley, special torque wrench, etc.), I'd like to know if there are any tests, diagnostics, or checks I can perform myself to narrow down the cause.
Has anyone experienced similar symptoms after a belt replacement on a Brose motor? Does this behavior sound more like a belt tension issue or a torque sensor problem or anything else?
Any advice would be greatly appreciated. Thanks!
