I have two road bikes that are fully functional and much nicer than I really need. I have a cross bike that may not be exactly nice, but if definitely works. I’ve been complaining to myself that I need to get rid of the cracked and broken bike frames that are collecting dust in my basement and yet despite all this I couldn’t help myself. I bought another junk frame.
I was thinking about how I would like to seriously test a DIY carbon repair and I just got the idea to type, “broken carbon frame” into ebay. That search returned no results, but ebay suggested some frames for me. One of them was a Raleigh R2.5 carbon frame that had been sanded down to the bare carbon and looked like maybe it had been dragged around under a car. I was immediately intrigued. On further inspection I noticed one of the drop outs said, “Cervelo” now I was really intrigued.
The Cervelo R2.5 has a terrible reputation. Apparently a large number of these frames were recalled because the lugged carbon tubes would become unbonded. The recall effected serial numbers greater then the one listed so I thought maybe it was safe. Besides the frame the auction also included a Ultegra Crank and 105 front and rear derailleurs. The opening bid was 40 bucks. Shipping a bit over 40. I couldn’t help myself, I bid 40 bucks more as a laugh.
Well now I have this bike, and the frame is of course cracked. I’ve never seen a frame shipped like this. The seller just wrapped it up in foam and bubble wrap then shrink wrapped the whole thing, before finally taping it all up in brown tape. It would have been much easier and cheaper to put it in a box. It took 15 minutes of cutting to get it out of the cocoon.
It didn’t take me long to find a crack. It took a slight squeeze on the rear drop outs to hear the sound of crackling carbon and about 5 seconds to see the big crack on the seatstay. The auction was “as is” but the seller didn’t indicate the frame was cracked, honestly though I wasn’t the least bit mad, in fact I was kind of happy, this would give me some carbon to repair.
First I took a dremel tool and ground out the material around the crack down to about one layer of carbon. Then I sanded alot, I sanded down around two inches in both directions from the crack. Next I cut about 4 pieces of carbon each one about half an inch smaller.
I cleaned everything up with alcohol then I mixed up a big puddle of epoxy and smeared it all over the frame. With plastic gloves I began laying up the carbon patches and smearing them good with epoxy. Once completed I wrapped the entire area up as tightly as possible in electrical tape.
It looks terrible, but it’s very strong and doesn’t crackle anymore when squeezed. When I sand it down it will not match the original weave pattern since my carbon is not weaved, but who cares.
Honestly I won’t be confident riding this bike if I ever get around to building it up, especially anywhere hilly. I won’t be that worried about the seatstay I repaired, if it breaks it will be at the edges of my fix and I think it will crack, but I wouldn’t want to risk it on a 30 mph downhill. I’ll probably build it up and ride it around slow on the rail trail and look really closely for cracks.
What I’m really excited about it painting it up all crazy modern art style like Dario Pegoretti does.