I just bought a 2011 SC 7.0 off of eBay at a reasonable price. The listing said “great shape” and “no damage to the frame.” It arrived today and I have been cleaning it and putting it together. While doing so, I find what I consider to be some pretty significant “damage,” though it may be cosmetic. From some googling I found one picture with similar damage where someone said it was caused when the chain derailed and ate into the frame. I know it’s not the clearest picture, but it is a “chip” down to the bare carbon behind the crank. The bare carbon then appears to be somewhat scratched. Up close, the edge surrounding that mark (the visible line a few mm outside the damaged paint) appears to be raised as if there was a sticker or some sort of extra layer there that ripped off. (Anyone know if Trek put something there to protect that area?)
So, my questions for those who may be able to answer are:
From what you can tell in my picture, is this just cosmetic damage?
In your opinion, does it change the value of the bike? If so, how much?
If it is only cosmetic and I decide to take no action or work something out with the seller, is there anything I can/should do to protect that area from additional damage?
Probably a question best answered by Carl from Trek (he’s on the board here) regarding the damage.
With that said, I believe this is more cosmetic than anything - the clearance between the chainstays and the chainrings, coupled with the bottom mounted brakes can allow the chain to get jammed in between the chainstays and chainrings from the bottom side.
Best bet is to pull the crankset off, clean the area up with a light sand, and then apply a clearcoat to keep the moisture out.
I would say that this is relatively common issue with the SCs, but it still should have been noted by the seller IMO.
From travelling/racing a bunch with my 9.9 during the past year, I will have to say that one of the things I am most pleasantly surprised at is how sturdy the SC actually is.
Commonly referred to as “chain suck”. The extent of the damage if the carbon isn’t eaten into is just cosmetic. If it get deeper than that, the possibility of a crack/failure there increases.
I have similar though probably less severe damage in the same spot. The rider threw the chain and it got stuck between the chain wheel and the chain stay in your case they didn’t appear to quit trying to pedal! There is a metal plate to protect the carbon that will come off and can be replaced. Take it to a Trek bike shop and they can replace the part and consult on whether it is safe. I think it is but not an expert. Put a chain catcher on it as well.
Same thing happened to my bike about a month after I bought mine last fall. Apparently was a very common issue. Hasn’t caused me any problems thus far.
It’s not a big deal and doesn’t really change the value of the bike. You can get a replacement for that little adhesive metal piece that’s all scratched up from a Trek dealer. It’ll probably only be a few bucks.
Get a chain catcher. This is the one I have on my SC 7.0 (bought after I did the same thing shown in your picture). It’s very small and effective. I think every new bike should come with one. (Some grouches will say that they’re for people who don’t know how to take care of their bikes, but tell that to Andy Schleck and his mechanics. Here’s Chris Boardman discussing chain catchers and the Schleck incident. I’m a former bike shop mechanic and know how to adjust front derailleurs, but crap happens… sometimes you hit a bump right as you’re downshifting or something like that.)
You can go to your Trek dealer and order a new coverplate for that area, it comes with expoxy. Get yourself a chain keeper on the FD and make sure that the FD is adjusted so the chaingear and FD doesn’t throw the chain past the small chaingear. All will be fine, mine looked just like that. Good luck.
I took my new SC7 out on its first ride today and had a similar problem. I gear shifted, the chain bounced and snagged between the chain set and chain stay, the aluminium guard pinged off and the pedals jammed. It was a familiarisation ride, I wasn’t riding hard and the gear shift was on a steady incline. On inspection there has been structural damage to the carbon frame (cracked) and cosmetic damage. Thoughts and advice on how to resolve this matter would be appreciated. I am concerned that Trek don’t deem it a manufacturing error and the warrant is not valid in this instance!
definitly not a warranty case but user/mechanic error. That said, it will happen with many bikes to drop the chain and stuck it between the chain ring and chain stay. it isnt a big deal even if a little bit of pain and carbon have gone. in 99% of cases… it s not structural and it s almost impossible to crack a frame at this specific area. there is a lot of material to reinforce it.
the picture dont show but most likely, you just made a scratch and it s something to live with. Get a K-edge chain catcher and this will never happen again. But it s not a manufacturing defect, it s user error…
I took my new SC7 out on its first ride today and had a similar problem. I gear shifted, the chain bounced and snagged between the chain set and chain stay, the aluminium guard pinged off and the pedals jammed. It was a familiarisation ride, I wasn’t riding hard and the gear shift was on a steady incline. On inspection there has been structural damage to the carbon frame (cracked) and cosmetic damage. Thoughts and advice on how to resolve this matter would be appreciated. I am concerned that Trek don’t deem it a manufacturing error and the warrant is not valid in this instance!
How could misadjustment of the derailleur, combined with your continuing to pedal so as to jam the chain, possibly be Trek’s fault? On a first ride, or really, before any ride, it’s your responsibility to verify that the bike will shift cleanly through all the gears on both front and rear derailleurs. If there is actual structural damage, you’d be best off to go to your dealer and inquire about a crash replacement frame, and have a talk with your mechanic about pre-ride adjustments to the derailleurs and brakes while you’re at it.
Sorry if the above seems harsh - but trying to claim this under warranty is what makes bikes more expensive for all of us.
As others have said its likely cosmetic only. I actually had the same thing happen to my TTX and rode it all last season with no on taken. Just cleaned the heck out of my bike and decided to patch it up. I’d suggest cleaning that area up, and put several layers of matching polish. Cheap and easy. Kind of lame for the seller to not point out…
For possible followers of this thread that have experienced chainsuck damage to their SC. I took my bike back to LBS explained the situation and quoted Trek’s warranty. The bike store got in touch with Trek on my behalf, Trek provided a replacement 2013 frame despite the original being 2012. I am pleased with the service, despite the mild inconvenience of waiting for a decision and replacement frame from Trek. The SC requires tentative gear shifting, it doesnt like gears being thrown and you need to anticipate the road conditions, shifting early.if you experience chainsuck in race conditions anticipate loosing 2minutes to rectify the problem. Unlike my last bike (Specialized Transition S-works) you can’t double shift without risking chain suck. Chain suck incidentally is when the chain slackens and catches under the bottom bracket, a chain catcher will NOT mitigate the risk. Overall, generally pleased with bike and after care service.