pdlamb

My front wheel is hopping wildly during braking, and as best I can figure, it's at or near the rim joint. The rim is a Velocity Synergy, which supposedly has a sleeve at the joint so it doesn't collapse under hard braking. I don't honestly see anything inside or outside the rim.


I've thought about trying to work some epoxy into the joint to hold it together, but I can't figure a way to flex the rim to get any glue inside it. Since this is a dyno wheel, turning it around isn't going to work. Are there any other good ideas for a fix, short of rebuilding with a new rim?

Mr IGH

The rim is defective, when the factory cut the spiral extrusion into individual rims they didn't cut it parallel. When the rim is built up and tensioned the joint is pulled tight. Only then can the defect be detected.

The only option is to call Velocity and have them send a new rim. They are well aware of the issue, it's existed since the company made their first rim and they've never addressed it properly. That's why I never use Velocity (or Alex) it's just a fact of life with them.

pdlamb

The wheel's actually a few years old, but the problem just popped up last month. Shouldn't any mis-alignment have showed up before then?

2lo8

I've never heard of sleeves preventing rims from collapsing under braking before.

Sleeves are just used to join unwelded rims, like pins. There's a piece that is inserted in the hollow box created by a double wall rim to bridge the ends of the rim. Pins are similar, except the extrusion has round holes in it and they use round pins to do the same job.

Homebrew01

Maybe you hit a pothole, which flared out the rim a bit, causing the brakes to grab unevenly.
The seam may not be the problem, or the seam hit the pothole, which is now a problem.

fietsbob

Smooth the edge, for now then , shop for a New rim..

an Identical one and you can tape the rim to the wheel and move the spokes over without messing up the pattern.