Sans arrière pensée...

Je vous rapporte simplement un extrait d'une conversation sur un forum populaire. Le post original est lancé par un type qui montre une photo de son cadre de très grande valeur. On y voit de petites fissures autour des haubans, à la jointure du tube de selle et il demande leur avis aux membres... "Est-ce grave selon vous? La suite est l'éternel débat sur "le cadre es fini" versus le "c'est juste la couche cosmétique, no problémo"... Et puis il y a ce type qui poste ceci à propos de sa propre expérience avec son propre vélo d'une autre marque: "I little anecdote about the BMC crack I mentioned. The bike was involved in an accident (hit broadside - at low speed - by a car). The front wheel was pretzel'd and the left side of the fork had an obvious impact spot (paint transfer), but no external signs of damage (no chips, cracks, or delamination). Of course the wheels and fork went in the trash. Insurance paid to replace the bike, which I did. After a close visual inspection by myself, and the mechanics at my bike shop, we could not find any signs of damage to the frame itself. Keep in mind this is a frame that has a naked carbon finish, so visually finding a crack is not easy. Anyway, I decided to send the frame to Calfee and have them do an ultrasonic scan of the entire frame, and give me a report. They found the right rear seat stay had a crack/delamination about 3" above the dropout. It wasn't visible externally, but their scan detected some sort of anomaly. It was on the opposite side from where the car hit the bike, and wasn't in an area I would have suspected damage. I'm not even 100% sure that the crash is what caused it, although I don't know what else could have. The bottom line is, you can't trust your eyes or fingers to determine the extent of the problem. Your situation is difficult. Paint can definitely crack without any other damage to the structure, but it can also crack because there is a problem underneath it. You don't have any way to differentiate between the two with your eyes and fingers. To re-emphasize my advice above, I would take that bike back to the local shop you purchased it from and demand it be replaced. Don't ask them what they think, or for an opinion. Tell them you either want a replacement or a refund (presumably it's still under warranty?)." Bref, en cas de choc, on examine... Comme on change de casque...