# Looking for help figuring this out...



## tapar1 (May 2, 2009)

I purchased an old stock 2009 Cervelo RS and built it up with Campy Chorus 11s... barely have 200 miles on the bike... while wiping down the bike after a ride I notice a scratch/gouge in line with the 34T ring on the crank where the chainstay meets the BB... anyone out there have any idea what is going on here... is it something I should be worried about... any insight appreciated, thanks.


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## ::dyslexic:: (Jul 13, 2009)

Could be a few things. Chain dropped or chain suck (most likely), bottom bracket not installed properly (i.e. spacers not in correct orientation), defect in the bottom bracket causing flex (unlikely).


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## tapar1 (May 2, 2009)

chain suck... that was probably the culprit... had an incident just before I took the bike into the shop for the first 150 mile tune up where I noticed a quick glitch in the drive train downshifting under load, when my cranks seemed to lock up for a quick instance accompanied by some nasty noise in the chain/crank area... too bad, first blemish on the new carbon frame... is this damage anything to be concerned about regarding the integrity of the carbon?


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## PlatyPius (Feb 1, 2009)

Grab the crank and check for wiggling. It's a Cervelo. They're famous for the BB insert breaking loose and moving around.

It seems apparent to me that the inner edge of the chainring is hitting the chainstay. There are bits of clearcoat on the chainring. Yes, it's serious. It *could* eventually saw through your chainstay.

The only adjustments to a Campy crank are the wavy washer, which is on the non-drive side, and putting spacers behind the cups. There is very little room for error there, though. The BB shell has to be within a very specific range, and you could probably only use the thinnest of shims there.

I would definitely check for BB shell misalignment or a loose insert. Also make sure the retaining clip is installed on the drive side cup. I don't know that it could cause any such problems, but you should probably check everything.

Can you take a picture from the top looking straight down at the crank and/or one from the bottom doing the same? Try to get as much of the chainstay and downtube in the picture as possible so we can see the crank in relation to them.

After you try the crank/BB wiggle test, of course.


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## tapar1 (May 2, 2009)

thanks PlatyPius... did the wiggle test and the crank is solid... the LBS I had build up the bike is a reputable bike shop... owner is Leipheimer's mechanic and did the TDF with Team Radioshack last year, though it was one of his shop mechanics that did the build... here is a pic from the bottom:


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## PlatyPius (Feb 1, 2009)

Ok, it definitely looks farther away from the chainstay in that picture. Therefore, I'll go with the rest of them - chain dropped at some point, maybe during building. It's odd that there's clearcoat bits on the chainring, though. Maybe you're just a powerhouse and you're flexing the frame/crank that much.


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## tapar1 (May 2, 2009)

hopefully this won't happen again... do you think this damage is anything that will compromise the carbon integrity... looks like it is just the clearcoat as I don't see any carbon fibers showing through... thanks again...


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## PlatyPius (Feb 1, 2009)

I just see clearcoat, too.

Try to clean as much of it as you can off of everything. If more clearcoat flakes appear, you'll know it's an ongoing thing.


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## em3 (Dec 25, 2005)

The OP already admitted that he did an Andy Schleck and shifted his front der while under load causing the chain to drop in-between frame and inner chainring...mystery solved. Lesson learned...never shift under load, especially your front der.
EM3
PS- that gouge looks pretty deep...you may want to get that checked by your LBS and verify that it's not structural damage


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