Today I got a stick wedged between my frame and tubeless valve stem. In addition to snapping the stem I widened the hole a bit.

Any suggestions on how to fix it? Current plan is to go over the whole area with some fiberglass cloth and then redrill the hole.

enter image description here

  • 1
    You've tagged this as carbon - so the rim is carbon fibre ? Photo makes the rim material look silvery like aluminium.
    – Criggie
    Commented May 19, 2019 at 4:40
  • Whoops. They are aluminum. This is the wheel crankbrothers.com/products/iodine-3-wheelset
    – dranxo
    Commented May 19, 2019 at 5:06
  • 1
    Is your bike insured? Those wheels look expensive, and stumping up the cost of an excess/deductable might be a better approach than repairing. What happened sounds like an accident, and not fair wear and tear. Good luck if you choose this path.
    – Criggie
    Commented May 19, 2019 at 5:20
  • Bought it used and it's about 5 years old. Doubt I can warranty it and unless renters insurance covers this I don't have a claim
    – dranxo
    Commented May 19, 2019 at 16:00
  • Is this from the tyre-facing side if the rim? That is, the outer wall of the chamber. How does the valve hole on the hub-ward side of the rim look like? Assuming a double walled rim profile. Which is suggested by having no spoke holes on the tyre-facing side.
    – gschenk
    Commented May 20, 2019 at 15:41

1 Answer 1


I would not fibreglass it - instead I'd remove the black coating 10-15mm around the edges of the hole and just over the "curve of the well".

Then I'd use a thin piece of aluminium plate and carefully conform it to the bed of the well. This would be a lot of careful hammering with a ball-peen hammer and perhaps a cold chisel. You also want the edges napped or relieved to smooth the transition up and down for the rim tape. No sharp edges !

Once its all fitting in place snugly, I'd drill the valve stem hole in a pillar drill, and carefully chamfer the edges of the hole.

Weigh the final piece now.

Clean both surfaces and then use a 2 pot epoxy to snot the patch part in place. Use a bolt temporarily through the valve stem hole to retain it while the epoxy sets, and leave for at least the maximum "hardness" time on the epoxy instructions.

You want to keep it totally below the "terrace" beside the clincher bead hooks, so the repair doesn't interfere with seating of the bead.

Also, you may choose to make a second plate of equal weight to adhere diametrically opposite the valve, to help with balancing the wheel and reduce vibrations at high RPMs.

  • 1
    I would add one item to @Criggies' detailed response. I would use a Dremel w(small die grinder) with a very small burr or stone. I would trim the edges of the whole. The idea is to smooth the rough jagged edges where stress cracks are likely to form.
    – mikes
    Commented May 19, 2019 at 11:32
  • The rim is hole-less, there's no rim tape to be considered when used tubeless.
    – gschenk
    Commented May 20, 2019 at 11:38

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