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

 

[withiniswithout]

The spoke was replaced. Now, two more spokes are broken. The wheel is 23mm, wider than the factory wheel, and 36 spoke instead of 32. It has 5,000 km on it. So, something ain't right. The original 19mm 32 spoke Rodi rim lasted 17,500 km.

I went to the shop. They were pretty casual about it. Said, well, let's replace the two broken spokes and if another one breaks, we will have to get a stronger wheel.

The tires are inflated firm, around 65 psi, not over inflated or soft. They are 28 X 1.5-700 X 380 with bolt on rotors.

If you have a recommendation for a good, strong rear wheel let me know.

 

[fooferdoggie]

The spoke was replaced. Now, two more spokes are broken. The wheel is 23mm, wider than the factory wheel, and 36 spoke instead of 32. It has 5,000 km on it. So, something ain't right. The original 19mm 32 spoke Rodi rim lasted 17,500 km.

I went to the shop. They were pretty casual about it. Said, well, let's replace the two broken spokes and if another one breaks, we will have to get a stronger wheel.

The tires are inflated firm, around 65 psi, not over inflated or soft. They are 28 X 1.5-700 X 380 with bolt on rotors.

If you have a recommendation for a good, strong rear wheel let me know.

it sounds like the wheel needs rebuilt from the ground up. once you have that may spokes break the wheel is compromised.

 

[withiniswithout]

it sounds like the wheel needs rebuilt from the ground up.

I looked at the hub and the rim and there's no indications of damage or stress.
I see three options: 1. Buy a good quality complete wheel that could cost anywhere from $80 to $500 2. Buy a rim and better spokes and use the existing hub, or 3. Just replace the spokes and leave the hub and rim alone.
The original wheel the bike was shipped with was a 32 spoke 19c Rodi. This was probably a $60 wheel. With the same riding conditions, this lasted 17,500 km without any spokes breaking. Eventually the rim developed stress fractures. But this shows that a budget wheel can be totally fine--I shouldn't need a $350 Mavic or DT Swiss wheel.
I'll ask the mechanic what his opinion is. I need the bike to be reliable and safe. I'm aware that the wheel is an interdependent system and you can't just put stiffer spokes on it or it might transfer the stress to the rim and hub and cause issues.
700c / 28-inch rear disc wheel with 135mm QR spacing, 6-bolt rotor mount, and a standard Shimano HG freehub body--I'm pretty sure these specs are correct.