carbon Crack Or Paint Crack!?

steve23

there is a mark on my road frame, about 5cm from the BB on the rear left chainstay.

the mark goes vertically on the outside on the frame, for about 2cm.

i cant tell whether it is a scratch, which could of happened as its benn put in the garage and other bikes next to it, or indeed a crack!?

any advice!? ive had a ride on it, and i cant hear any "creeking" or anything untoward, but i doubt i would have. it might of been there for ages, as its a few months since ive ridden that bike!

thanks

redddraggon

Take a pic and post it on here, until then I doubt anyone could offer any real advice.

Because CFRP is relatively brittle, a crack would likely have propagated through the entire structure, becoming very noticable.

Monty Dog

More than likely a superficial scratch - any crack would likely to be full-thickness and you'd probably feel/hear it. Take out the back wheel and push the rear drop-outs together - is there any discernable movement - does the mark/crack open? You could also try a DIY dye penetrant test - using a spirit based marker pen or even paint, apply to the crack and try and wipe it off with a light solvent e.g. lighter fuel. If it's superficial, it'll wipe clean - if deeper, some residue will remain and will probably merit further inspection e.g. your LBS for a potential warranty claim, or a local Engineering NDT specialist for a second opinion.

SteveR_100Milers

I would have thought that a 2cm long crack in a CF composite frame would be noticeable when riding, likely even fail completely. Liek red says post a piccy better still get an expert opinion.