Firmware Update Causing Speed Issues?

Bevans99

New Member
Region
USA
I have a 2021 Trek Rail 7. I took it in for service at a Trek shop last week and they mentioned the firmware needed to updated. Once I got the bike back, I have had issues with the speedometer jumping around and the motor cutting out at higher speeds. No error codes are being thrown. The Trek dealer talked to Bosch and now they want to replace the speed sensor to see if that resolves the issue. Curious if anyone else has had similar issues after a firmware update? I don't want to pay for a sensor replacement only to have it not resolved. I rode the bike the day before I took it in with no issues, so it seems that firmware is the culprit.
 

Stephen - Bosch Team

Active Member
I have a 2021 Trek Rail 7. I took it in for service at a Trek shop last week and they mentioned the firmware needed to updated. Once I got the bike back, I have had issues with the speedometer jumping around and the motor cutting out at higher speeds. No error codes are being thrown. The Trek dealer talked to Bosch and now they want to replace the speed sensor to see if that resolves the issue. Curious if anyone else has had similar issues after a firmware update? I don't want to pay for a sensor replacement only to have it not resolved. I rode the bike the day before I took it in with no issues, so it seems that firmware is the culprit.

This seems like the speed sensor is the root of your issue. I would think this is a coincidence at best with the software update. For that bike, the speed sensor is a Trek part. Whether Trek or Bosch on the parts on your bike, a 2021 model should be well within warranty. I would try a new speed sensor and report back with findings.
 

Bevans99

New Member
Region
USA
Trek replaced the speed sensor and the issue did go away. It looks to be coincidence that it happened the same time the firmware was updated. All good now.