fronesis

Problem Solved, End of Thread: I adjusted (banged on with screwdriver) the derailleur cage so that it was definitely clearing the chain; I then checked the RD hanger, and it was way out of whack, so I straightened it. Bike might shift even better now, and be slightly quieter (and much of the noise was really normal noise anyway). Thanks to everyone who helped out here!


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I have about 800 miles on a new bike with a Campy Athena 11s drivetrain. It's been shifting beautifully, but I've been bugged by some noise from the chain or cassette, especially when on the smaller cogs. I might just be being a hypochondriac about this, thinking that my drivetrain should be silent. But it seems odd to me that I can't dial out this chain noise, even when the bike is otherwise shifting absolutely perfectly (and the chain is clean and oiled). Even more odd, I can't make the noise go away even when I just put the derailleur on the smallest cog, loosen the cable tension, adjust the L stop so that it's perfectly aligned.

Maybe it's just "normal" chain noise. My other theories include: bent derailleur hanger (but it's a brand new bike, no wrecks); chain somehow installed by LBS correctly (bike was built up by my LBS); a worn chain after only 800 miles; or THIS:


Does this look right to you? I couldn't compare to another 11s derailleur from the rear view, but it looks like it might be bent to me...Again, this is brand new Athena 11s derailleur that has been on the bike for 800 miles; as far as I know it was like this when it came out of the Campy box. It's possible the LBS mechanic bent it; I certainly didn't.

Drew Eckhardt 

Maybe.

I've heard that some Campagnolo derailleurs aren't supposed to be vertical.

My 2004-2006 Record Titanium long cage lower pulley is a bit outboard although I bought it used and could theoretically have bent my 1/4" thick 6-4 titanium hanger sometime in the 17 years since I bought my frame although that seems unlikely due to the stiffness and how far you need to bend titanium for it to take a set.

Sheldon Brown writes

fronesis

Thanks, Drew. That's helpful.

After spending 4 hours on this, I think I may have just been crazy to think that I wasn't going to have *any* chain noise. I now have the drivetrain shifting perfectly, and I can dial the tension up or down so as to create both a higher pitched rattling (too tight, chain rubbing the bigger cogs) and then a lower pitched sounds (too lose, chain rubbing smaller cogs). The spot in between is not silent, but it's not rattling/ticking, etc. I think I should just ride the bike and stop worrying.

SBinNYC

Shouldn't that be the H screw you adjust? However I don't think that's your problem from looking at the pictures.

The far bottom of the derailleur cage inner plate appears to be bent towards the outside. If you look carefully, you will see that the chain is rubbing there. This doesn't affect shifting performance one bit, so it's consistent with your observations.

If this were not a brand new expensive derailleur, I'd just insert a flat screwdriver between the bottom jockey wheel and the inner plate and bend the inner plate a bit to the inside.

FBinNY 

Looking at the rear view photo, it appears that the lowest part of the inside cage plate is bent so it's rubbing on the chain.

I suspect that maybe somebody dropped it before installing, or something like that.

If this isn't an issue of photo distortion, pull the derailleur and straighten the plate and your noise will go away.

BTW- your hanger seems to be bent inward, but that's a separate issue.

fronesis

Yes, I meant to say the H screw; I just mis-spoke there, as I did in fact adjust the H screw.

Looking closely it's very hard to tell if the chain is hitting the bent part of the derailleur, but I guess it couldn't hurt to try to pry it out some.

But the bent derailleur hanger worries me even more, as that might be the source of my problem, and I'm not sure how I got a bent hanger on a brand new bike. How can you tell from the photo that it's bent? (I can't see it.) I assume I need to buy a new derailleur hanger (since the frame is carbon) or is there a way to bend it straight.

FBinNY 

I can't tell from the photo, bit the cage should hang on a place parallel to the sprockets. Yours appears so be angled in at the bottom, almost parallel to the line of the spokes.

BTW- if you've had to adjust trim or limits since owning it, especially if you needed to adjust outward, that's solid evidence that the hanger is bent. The most common cause of bent hangers is simple manhandling -- the bike falling over, getting bumped by another bike, being laid down in the trunk or your car, etc.

fronesis

Yes, yes, I definitely see that: it's what I was asking about in my original post. The thing is, I can't tell if the part of the cage that bends in at the bottom is actually hitting the chain. But it sounds like it is definitely not supposed to look like mine does. Bizarre, since it's new.

The bike is only about a month old. It's never been bumped, fallen over, or wrecked. It was laid down in the trunk of my car, but with the derailleur facing upward. This is why I'm doubtful that the hanger is bent. I did have to readjust the derailleur when I first got the bike, but that was because my LBS mechanic didn't take the time to dial it in correctly – not a campy guy, I guess.

FBinNY 

Stop obsessing and fix the problem.

The inner cage plate is bent, straighten it at least enough to clear the chain (assuming it's metal). You can do it on the bike with a screwdriver by levering it against the chain. It's not the ideal way to do it, but it works. Or do it right, by removing it and flattening it on an anvil.

As for checking the hanger, take a straight edge and lay it on a secant against the largest cassette sprocket and eyeball to see if the RD cage seems to be parallel. You can to a field hanger adjustment by putting a hex key in the upper pivot bolt and levering it the way you want to go.

OTOH- since the bike is new, you can go back and let the shop finish the job the way they should have in the first place.

fronesis

Thanks for this. The shop that built the bike got so many easy things wrong, that I don't trust them to deal with something more subtle like this. From the beginning they seemed uninterested in really helping me, and seemed to hold it against me that I bought a frame set and components myself rather than purchasing from them.

I'll get on both projects next chance I have to look at the bike, and then I'll report back here.

EDIT: Had a moment this morning so I carefully bent the cage back. No problem, no damage caused, and now the chain is clearly running free from of the cage on both sides. This had no effect on my drivetrain sound, as I think that despite the bent cage the chain wasn't rubbing enough to cause a noise.

I also looked closely that the derailleur and cogs with a straight edge, and IF the hanger is bent it is only just barely bent. Of course, with the narrow spacing on a 11s cassette, I'm sure it's possible that I small bend in the hanger could lead to issues.

I didn't want to guess at this (and my Athena derailleur doesn't take a hex key; it takes a Torx T25), so instead I just went ahead and ordered the Park Tool for measuring and adjusting the hanger. I'll measure on Friday and adjust if needed.

fronesis

Just a big thank you to all those who contributed here – much appreciated. I edited the original post to indicate problem solved.