I posted this over in the road forum too, but thought I'd post here for additional opinions.

During my last ride, I kept hearing a weird whiz sound when I pedaled down hard on the drive side. I figured it wasn't a big deal, but when I got home, I noticed my tire had been rubbing on the inside of the chain stay.

I took it into my LBS to have it checked out for safety. Three mechanics looked at it and the general consensus was "we're not really sure, keep an eye on it." It's definately rubbed through the clear coat, veneer layer and into the first couple layers of carbon fiber.

So, my question is, would you ride on it? I've attached pictures for reference. The spot is about the size of a big pea.

PS. The frame is a Trek 5200.

I'd want some epoxy or something in there.

^^^+1 ^^^

It's hard to tell from the picture. Does it go all the way through? On the one hand, it's not like a fork or something, but it's hard to know if that will lead to any trouble or not. Keep an eye on it sounds like good advice.

There is a carbon frame repair service. You could send the picture to them and see what their take is and what it would cost to repair.

No, it doesn't go all the way through. The rear triangle doesn't feel week, but I really don't want to be on the bike if/ when it fails.

Did you explain it to the mechanics like this? Did any of the 3 of them consider pulling out a dish stick and checking your rear wheel?
If you're rubbing the frame on only one side, then there's two ways the tire got way over there:
1) Misaligned in the dropouts. Since the Trek 5200 has (IIRC) vertical drops, this is highly unlikely.
2) Poorly dished wheel. Yeah, I'd check the alignment in the drops first... but I'm betting there's a dishing problem.

I suppose 3) could be that you're just such a beast that you flex your frame so hard the tire rubs, but I'd be more willing to go that route if you were on vintage steel, not OCLV carbon.

Yeah, I explained it to them. Unfortunately, it was my fault. I had recently replaced the rear tube and didn't get the rear wheel seated straight in the rear drops.

Live and learn, right?
I wouldn't sweat it too much. Back in the early days of Trek CF bikes, I had worse looking damage than that to one of the CF main tubes on my 2100 (CF tubes bonded on Al lugs to Al stays and forks.) I raced that bike at 215 pounds and I'd probably still be riding it if some crapwad hadn't stolen it out of my basement.

Calfee is the hands down expert in CF repair, and they should be able to provide some insight. I would start there.

https://www.calfeedesign.com/howtosendrepair.htm

I guess if I would have checked tjspiel's post, it would have saved me 15 seconds. On the other hand, always nice to have two opinions that are complimentary.

After talking with a bunch of people and the varying responses on BF everyone seemed to confirm that I shouldn't ride it. I went ahead and ordered the Nashbar road frame for $100 and should have it in a week.

Calfee's repair will run at least $450 and has at least a 6 week turn around time. I'll just swap all the components over to the new frame and go from there.

Although I'm disappointed at the loss (not to mention frustrated at myself for being so careless), I'm excited to build up a new frame.

Hmm. I'd have ridden that. Pop some epoxy in the indentation and check it periodically. Chainstays don't fail catastrophically for the most part.