I have two identical On One carbon frames, both have had the seat post clamping area (top of seat tube) shear. I sent one to a carbon repair place – their work was great, but the solution was to simply install a shim down to 27.2 (from 31.6).

For my second frame, I reckon I can do the same thing myself and save some money. My plan is to buy one of these shims (Cane Creek alloy shim) and somehow glue into the frame.

My questions are:

1) Any reason why I couldn’t/shouldn’t do this?
2) What would be best way to glue this in – regular old superglue, expoxy of some sort, or something else?

What depth shim did the carbon place install?

Good question – I have no idea, but it definitely goes past the seat tube/top tube junction.

To clarify – the one the carbon repair place put in is working fine, has been for months. It’s my other frame, with same clamp area shearing problem which hasn’t been repaired yet, which I am wanting to repair myself.

Epoxy, but make sure you fully coat the alloy shim to minimise the risk of galvanic corrosion

Try and get the longest shim (you can get 120mm ones) you can and get a special epoxy for bonding alu to carbon.

I am not an expert.