Bicycle Mechanics - Chain suck and frame damage

On my last ride I had my first episode of chain suck when shifting from the middle to big ring on the front, and noticed a small gouge in the chainstay afterwards. I'm wondering if this is cause for concern on an aluminum frame -- the bike is a Trek 4300 MTB with the Alpha aluminum frame. The chain didn't get jammed too badly, and I was able to clear the chain with a quick back-pedal and keep riding. I guess what I'm wondering is how much damage does it take to weaken an aluminum MTB frame to where you should worry about it? Attached is a picture of the chainstay -- the gouge is down to the metal, but from what I can tell the frame is not bent in that spot or otherwise messed up in some obvious way, and I didn't notice any further problem for the last 10 miles of the ride.

Thanks!

Hmmm... one more try on the attachment (62K):

Does the gouge go completely through the tube? The damage is not gonig to cause you any problems on your rides. Although if the tube were to snap, thats where it would break at and the probability of the tube weaking are higher but not high enough to cause concern. Just ride untill it breaks (or doesn't) and then get a new frame, because sooner or later you will end up getting a new one-- it's irrisistable!:D ::sigh:: bike lust :)

Originally posted by kewlrunningz
Does the gouge go completely through the tube?
Nah... from what I can tell the damage to the metal is minimal, at least on the surface. I'm sure I'm just being overly paranoid, but figured I'd ask in case this is something I should keep an eye on.

Thanks! :)

I have an old Bridgestone RB-1 road frame where the chain sliced completely through the chain stay. I road it that way for about a year. It was a steel frame though.

no way, that's nothing to worry about at all. Maybe just dab a little paint in there so it doesn't start to chip around the scratch.
The biggest worry is dropping your chain onto the bottom bracket from your inner ring. Sometimes people will pedal and scrape the BB badly. That sometimes leads to cracking at the BB on aluminum frames- it's rare but thats the only chain drop damage that I've seen affect the frame...and a little electrical tape wrapped around the driveside BB shell would stop that if you drop your chain alot for some reason.

Originally posted by Grendel
[B]On my last ride I had my first episode of chain suck when shifting from the middle to big ring on the front...

I'd be more worried about the chain suck, since that can really cause you heartburn. The tiny scratch is no biggie.

So, make sure your drivetrain is cool.
Chain is not stretched (Park has a tool to measure it.)
Chain rings are not worn.
Cassette not worn.
Everything is moderately clean.

Obviously cleaning is the easiest and cheapest.

Any one of these three or a combination can cause chain suck, so if it happens regularly when you ride, figure out the problem and get it solved.

I busted a chain once because I had horrible chain suck that I kept ignoring.....Fortunately, I was able to repair and limp home, but not much for a ride on that day.....

Yeah, the chain suck is something I need to keep an eye on -- this was the first time it's ever happened and it acted okay afterward, but I don't wanna tear anything up by it happening again. The bike is pretty new and everything has 520 miles on it -- I'll check the chain and the mid-ring (which is where almost all of my riding has been) to see how they're doing.

Thanks all! :)