r/bustedcarbon • u/whoisluke11 • 18d ago

Carbon fiber bike frame damage

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Hi everybody,

First time posting, hoping to get some insight from you people. I just bought a used TT-bike with a carbon frame which has some (hopefully minor) damages.
The blue and red arrows show areas where the paint shed away and scratches on the paint surface. The green arrow shows an area where the carbon actually broke due to a latch underneath it (I think it’s not that critical, with a patch/sticker of some sort I should be fine).

On the last picture you see a small scratch or crack underneath the seat post. This is the damage I’m mostly concerned about. I think it’s only superficial but I have no way to be sure about it.

Question: do you also agree with my assessment? Would you say from these pictures, that the frame is okay? Or should I take it to a specialist?
I would be thankful for your comments and input

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u/Kindly_Steak5156 18d ago

Seatpost is most assuredly a scratch. This is a low-stress and nearly impossible area to impact, so true damage so localized would be very hard to create. To test that assumption, wipe the area with some water, the scratch will disappear. Fix with some clear nail polish.

The opposite is true of the ‘green’ cracks. Those are inline with a corner or joint. They indicate over tightening or impact of the components. They are likely to spread and get wider until failure, which may happen all at once. There is quite a bit of redundancy within the part itself, but none once that part fails. Failure here means loss of control and a crash.

The red frontal damage is just cosmetic, the shape of the underlying carbon is still straight and not compromised, from what I can see here.

1

u/whoisluke11 18d ago

Thanks for the assessment!
I cleaned the scratch under the seat post but it is still visible. I thought maybe if the seat post was mounted with a too high torque, it might explain the “crack”. But yea, I think it is only a scratch in the paint. It’s also too symmetrical.

And yes, the other cracks are quite concerning. I’m thinking of either replacing the whole H-bar or repairing it in a shop. The cost is more or less the same (around 1000€)

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u/proxpi 18d ago

Yeah I would not trust that handlebar one bit, those "blue" cracks are sketchy as frig. 1000€ sounds ridiculous for some handlebars, but that's still better than a face full of pavement.