Broken Velo Blunt SL rim

Unicycles and Equipment
1

Hey guys. I just went to check out my road 29er today and I noticed the tire was flat. When I took the tire off, I noticed two fairly obvious “bulges” in the rim (see pictures). There was an obvious “snake bite” in the tube (between where the two bulges are, but the bead of the tire was fine.

I built this wheel up at the end of July for the Yunnanuni unicycle tour in China. I used it for over 200km there but I used Gilby’s G29 for most of the tour since he was injured. Since then I have been riding it to class every day (maybe 3-5km a day).

About two days ago I tightened the spokes, possibly too much which could be the culprit. I’m wondering if this failure is my fault or if I might be able to talk Velocity into replacing it for me. (Unlikely since they will blame it on being used on a unicycle…)

The bulges in the rim are near the join (so opposite the valve hole). They are both on the left side of the rim roughly each positioned at spokes. They are 4 spokes apart so one is at a left spoke and one is at a right spoke (both bulges on the same side of the rim however). I’m wondering how this could have happened.

It’s hard for me to get better pictures since I only have my phone. Let me know if more description would be useful to understanding this problem.

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2

It’s hard to tell from the pictures, but It looks like either you landed a drop very wrong, twice, or there was a manufacturing defect. The sidewall is separating from the outer wall of the rim, yes?

Absolutely I would try to get a warranty replacement. Who cares if it’s on a unicycle, it failed in a way rims simply should not fail.

PS Did the spoke holes pull out as well? perhaps a picture from the side.

3

From the pics it doesn’t look like a spoke tension problem. As Max said, it looks like a pinch situation with a curb or a drop. The snakebite hints that it would be an intimate encounter with a curb that caused it. I once had that happen on a bike with a Mavic MA-3 on the first ride on the wheelset.

Typically a spoke tension problem tends to twist the whole rim, not just one side.

4

More pictures. The spoke holes are fine.

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5

Also, tire pressure was around 65 psi, so I’m pretty positive the rim didn’t bottom out.