Bonding CF to SS Bearing? (DIY CF jockey) UPDATE w/ pics

[timj]

I've recently CNC cut some custom jockey wheels out of a carbon fiber sheet that I had laying around and am having trouble bonding them to SS bearings. Originally I had just used epoxy resin and put a generous amount around the flanged part of the bearing. After installing them on my bike the top pulley lasted all of about 5 minutes before separating itself from it's bearing.

How has everyone else been able to secure bearings to CF pulleys? I'd really appreciate any help.

(CF sheet is 1.5 mm and bearings are 5x10x4 mm flanged bearings.)

pics:

[timj]

I noticed that with 1.5mm thick pulleys there was way too much sideways play on the chain. So I decided to laminate two of the pulleys together (making it 3mm thick). I had to file the tips of the sprocket down but now it meshes with the chain very well. It also gives me twice the gluing area with the bearing so I'm hopeful that this will last.

Ideally I would have liked to make this out of 2.5mm carbon. I haven't had a chance to weigh it yet but it's definitely lighter than the stock pulley. I will ride it for a couple hundred km before making the upper pulley, just to make sure that it holds up.

I also plan on making an inner mech plate. So I will keep this thread updated.

If anyone's interested in the .DXF files just shoot me a PM and I can email them to you.

pics:

[Boonen]

Nice work Tim, I think you'll do better with the thicker pulleys as well.

[cyteen]

In the past I have had success with first using epoxy and when that came loose using super glue (cyano acrylate) to fix the epoxy to the ss spindle. Using two stages was better than either one alone.