luckily, i don’t have to deal with this, but the ‘damaged specialized transition fram’ thread got me thinking:
does the LBS know what to look for to see if a carbon frame has structural damage? what do they look for? can they tell without consulting the manufacturer?
let’s say that it’s not obvious (no broken fibers/clean breaks to the tube interior/etc). you can see that there is paint damage, but can’t tell how bad it is.
does your mechanic know any better?
will they send you out the door on a death trap? scare you into a new bike? are they liable if they tell you it’s cool and it fails?
To be fair, some places know their $hit, and may be able to tell. others, just try to sell you $hit. do you believe them? send it to the manufacturer? ride steel?
in long:
If you can see significant impact in the composite there is a fairly good chance that the composite may be debonded in between the layers of the composite. In the lab we use a multitude of methods to test and see the damage area such as ultrasonic wave propagation.
Thinking of what the LBS would have the best it seems they would be able to do is tap on the composite. If one has a fairly trained ear you can hear where a composite is debonded… but i dont think i would trust the LBS for that.
It really depends on the shop, but I’d say that many shops have no more ability to evaluate damage to a carbon bike than anyone else.
I took the fork from my road bike into a shop last year because I saw a small mark on the steerer tube that I was concerned about. I took it to a shop that I didn’t go to very often because they are the only local dealer for this manufacturer, and I wanted them to send it back to the manufacturer for them to look at, and hopefully replace under warranty if it was truly a problem. This was a carbon fork, with aluminum only in the dropouts. The mechanic takes a look at it and instantly says “that’s fine, it’s just a little mark from where the stem clamps the tube, it’s not cracked.” I wasn’t so sure and still wanted it to go back to the manufacturer. He then proceeds to tell me that even if the carbon was cracked a little bit, it won’t be a problem because the aluminum insert that’s bonded in the tube will prevent it from failing catastrophically. My response was WTF?!?!?!?!?!?! This fork doesn’t have an aluminum insert. You look in the steerer tube and there’s just carbon. No aluminum and nothing bonded in place. I don’t know what he thought he saw, but there’s nothing there. When I called him out on it, he actually argued with me that it was there. He said that I just didn’t know what I was looking at and that it absolutely was there. He then went on to claim that this manufacturer puts aluminum inserts into all their forks. They don’t. This wasn’t some pimply teenage kid either. This guy was probably in his late 20s to early 30s and had been working in this shop for quite a while. I would love to have just walked away but the next nearest authorized dealer is about 40 miles away and I really wasn’t comfortable with the fork the way it was, nor did I want to pay full price for a new one if this was truly a warranty issue. The manufacturer would only look at it if it came back from an authorized shop.
I then asked to talk to his boss. The shop owner comes along and he and I remembered each other from the racing scene many years before. I explained the situation and told him I wouldn’t deal with the mechanic. He takes care of things, sends the fork back and I get a warranty replacement two weeks later.
I am interested in knowing what others think about this. On my ride last week, a rock flew up and hit the bottom side of my down tube and made a loud smack. I ride a Look carbon fiber bike and did a thorough check of the bike after the ride. On my most recent ride, I now hear a loud click when pedaling. I am hopeful this is just an adjustment that needs to be made with the deraileurs or maybe something to do with the bottom bracket, but I am also a little worried there may be a structural issue.
I plan to take it to the LBS to have them take a look.
If this frame is toast, I plan to go TI on all future bikes.
I’m going to say 99.99% no and I wouldn’t trust a LBS decision on this anyway. If a carbon frame needs to be looked at for damage, I’d send it back to the manufacture and let them take a professional look at it. I had a Felt carbon frame a few years ago. T-boned a Suburban that pulled out in front of me and the rear wheel hit the inside of the rear stay causing some damage to the frame. Insurance company gave me a replacement frame and let me keep the old frame. I shipped the frame off to Felt and had them inspect the frame. I was more comfortable with Felts inspection of the bike than my LBS.
