Below is an experimental carbon fiber brake rotor. I saw one years ago and wondered why I hadn’t seen another since. The answer, because they don’t work for very long.

I thought that this might happen, but I was interested in seeing how long it would take. Honestly, I hoped it would last a month or two. I didn’t think that it could be such a failure.

In the initial test, I tried a few 20 mph stops. The grip increased with each stop until #5. During which, a lump began to form in the break feel. Soon after a hunk of brake surface tore away from the disk. When I looked half of the surface was just hanging.

I think the problem was heat building up in the disk during the hard stops. It’s my guess that the heat combined with the high torsional load caused the epoxy to weaken. In other experiments I have done heat has played a role in failures. The question moving forward is how close to the heat can this epoxy be before it is affected. For now though, my carbon fiber doesn’t really have any place as the actually braking surface, but it could be used to support a brake surface.