Josef:Carbon Fibre Repair

= How to repair a Carbon Fibre Frame =

This year I managed to ruin my bicycle frame under Styrkeprøven, 540 km Trondheim-Oslo Cycling. Those who know me also know that I have a bike as a working horse, not as a design object.



Considerations
Thus, the consideration was:
 * Get a new frame from Radsport Rose : estimated costs 849 € + 8 hours of work (50% reduction included, plus removal of all parts)
 * Get a repair from Otto Jaeger, estimated costs 3500 NOK + 6 hours of work (deliver only the frame)
 * Do it yourself :-) -

Do it Yourself
And guess what, on Youtube you find good examples on the how to, and at Conrad Elektronik  I found what I was looking for:
 * 190 235-0 Kohlegewebe 0.5 m² (Carbon Fibre role) - 39,95 Euro
 * 888658 - 62 Harz und Härter HT 2 296 g (2 component glue) - 17,95 Euro

Thus I started and here you can see the results - Not that nice, but working

And if you are interested in the how-to, read these lines:
 * 1) sand down the repair area
 * 2) create a plastic cover as an underlay for the carbon fibre (about 1 cm longer at each side than the carbon fibre)
 * 3) cut two pieces of carbon fibre, in my case 15 x 8 cm
 * 4) mix the two-component glue according to the tolerances, in my case I used 40 g epoxy (resin) and 19 g polyamine (hardener) - Note: half of the amount would have been enough
 * 5) float the first layer with the epoxy
 * 6) add the second layer on top
 * 7) float the second layer with epoxy
 * 8) wrap it around the sanded area, ensure that the plastic is on the outside (the epoxy has to overlap)
 * 9) tape with with conventional tape (see picture)
 * 10) Give it 8-10 hours to harden, remove the tape and the plastic, and then you will see that epoxy has spread out over the frame. If you had plastic underneath you can remove that epoxy. You can also sand the new repair, no problem.

Lessons learned
Though the frame is "more stable than ever", there are some lessons which I learned
 * Cover your frame outside of the sanded area with some plastic, such that you can remove additional epoxy easier
 * Use only a thin layer of expoxy on the carbon fibre. I used to much, and when I taped (wrapped) the plastic it all smeared out
 * Use small isolation tape for the first round. Better results, as it tolerates more pressure (31Mar2014, Glenn's racer)

Otherwise, "nice and easy". And the total costs of 60 € and 4 hours of work were worth it.

My recommendation: give it a try instead of throwing away your frame.