Originally Posted by 79pmooney

I repaired a steel sport Peugeot circa 1990 with carbon fiber unidirectional and boatbuilder epoxy. Both chainstays were cracking just behind the bridge. (Bike was hit by probably an SUV front bumper. Fork trashed, a dent in the top tube and both rear dropouts pushed several inches to the right. The straightened easily. Should have been the first clue but I missed it. 3 weeks later - and after falling in love with that collection of parts' ride - I saw the cracks. I used to build polyester fiberglass boats,. a couple of vinylester one-off boats and done much building of furniture, repairs, etc, with the Gugeon Bros epoxy. Someone had given my a couple of feet of the uni-d.

So I went at it. Nothing to lose. That frame cost me $20. Complete investment to that point was $105 plus parts and wheels I had on hand.

I decided the repair should be spiral wraps in both directions starting up the top and seat tubes and ending on the chainstays. Masked off the tubes where I wanted to end the repairs with clean edges to trim the fiberglass to. Started in on the repair. It was hard. The CF didn't wet out and go limp and malleable like fiberglass. It had binder "threads" of plastic that didn't break down with resin and fought me doing anything. Finally got it to lay down tolerably. Cleaned my tools and hoped for the best. Came back an hour later. Everything had expanded and pulled away from the steel. The bends were just too tight for that stiff CF. When this sets up, this frame is going to be trash!

But I had inner tubes! Old dead inner tubes. Lots. So I grabbed scissors and started cutting them into strips. Taped one end to the steel on the main frame tubes and wrapped tightly in spirals, both directions just like I did with the CF, beyond the repair end and taped that remaining clean and dry inner tube to the chainstays. That compressed the mess back to the frame and sticky resin dripped copiously. Not much more I could so I walked away and tried to forget what I had just witnessed and done.

Next day I came back to dissect the corpse. A corpse wrapped with black rubber, not white muslim! Started unwrapping the inner tube. And it all peeled off cleanly! Leaving gorgeous shiny black CF weave. Like a high quality vacuum bag! Yes, two of the tightest corners didn't quite pull down but a little black Marine Tex filled that nicely. My boat building skills came through nicely with the clean taper to almost nothing at the masking tape edges. I barely had to sand after trimming with box knife.

I had to grind off a little CF at the outside of the chainstay to get the chainring to clear but that was it. Crankset back on, wheels and it was off for a ride. Whoa! The stiffest BB'd Peugeot ever made! Fun! 8k miles later I retired the frame because it had been hit hard and was probably going to break somewhere else and I didn't want to be riding it when that happened. But that BB repair was still rock solid.

The story of Jessica. Jessica who lives on as Jessica J, her custom replacement with copied geometry for that sweet fit and feel, ti tubes for the ride, custom dropouts that allow any track cog made (Jessica J is my first hill fix gear; designed for flip-flop hubs to be ridden as road race bikes were over 100 years ago.) And Jessica J has a high BB so I can run the 175 cranks my knees love and enjoy curvy mountain descents!