Spoke with speed sensor magnet broke

[withiniswithout]

Last night my Intuvia Bosch display looked normal but the assist from the motor was intermittent. I discovered the spoke with the magnet was disconnected at the flange hole. The J end feels rough. The hole it came out of is clear, no broken piece left in it. I will tape it to an adjacent spoke and take in to the shop, but was wondering what the hell might have caused this. The magnet is still on the spoke. Adjacent spokes seem fine.

 

[stompandgo]

The shop should check the wheel for damage and corrosion. The J bend is a stress point, and something stressed it to the breaking point. Once one goes, the rest can follow if not properly addressed.

 

[withiniswithout]

The wheel was replaced two and a half years ago so it is fairly new. Boh! as they say here in Italy. Possible there is hidden damage.

 

[stompandgo]

Why was the rim replaced? Were the spokes replaced with the rim? Or are you saying that the whole wheel was replaced?

 

[withiniswithout]

Why was the rim replaced?

The rim had stress fractures spidering out from where the spokes mounted on the rim. The shop put on a whole new rear wheel.

 

[stompandgo]

You are probably going down the same road as the original wheel. My take is to have the wheel thoroughly inspected. If everything looks good, replace the spoke. Once another one breaks, you've got to look deeper.

Common causes of wheel stress are:
- Riding the bike over the weight limit
- Underinflated tires
- Unusually rough roads
- Riding in corrosive environments (rain, salt water, etc.)
- Storing the bike wet