Waves77

My chain seems to have quite a bit of drag, and as you can hopefully see in the video, the pulleys kinda "bounce" through the pedaling motion.

The low screw is definitely a bit off right now, but I've played with the high/low, tension and pulley height and I'm still having the same issue.

Any ideas?

EDIT: Chain is a KMC 11 speed.

Shimagnolo

Chain looks too short to me.

Waves77

Wouldn't that only cause issue in the big-big combination?

cny-bikeman

No idea what you mean. Drive train seems very quiet and the last combo shows the chain at extreme stretch, where any imperfection in roundness anywhere in the drive train will show up. Is there an actual functional issue that you are having?

Waves77

It's kinda hard to hear in the video unfortunately (used my phone), but there's a lot of drag, like something is rubbing.

Are the pulleys supposed to "bounce" a little through the pedaling? It's not the front derailleur rubbing anywhere either, already tried that.

onespeedbiker

It's very hard to tell from such a grainy video. But yes a too short chain can affect other than just the big big combo. Campy is designed around the longest chain possible while Shimano suggests the shortest chain possible. I would guess you need two or four links (you can only add two links at a time) best to run the small small combo and see how many links you can add before the chain starts to sag; that would remove the additional tension through much of the big chain combos. As far as the pulleys jumping around #1 caused by two much tension #2 caused by stopping the drivetrain shifting then starting the drivetrain; shifting is much smoother if you are pedaling at the time of the shift. other than that more info is needed and better pics..

Waves77

Thanks, I'll have to try and add a couple links. I sized the chain using the big-big method (without putting the chain through the rear derailleur).

Any tips on what exactly to take better pictures of? (particular angles or front/rear gear combos).

Waves77

I'm an idiot. You guys were right. I did the big-big measurement but forgot to add two links on top of that. I'll add two links to the chain and report back.

Waves77

No dice. Issue is still there despite the longer chain.

Michael Angelo 

Look at pages 5-6. Also make sure you have the derailleur cogs lined up correctly at the high position, before adjusting tension on the shift cable.

https://www.campagnolo.com/repository...AINS_09_11.pdf

Michael Angelo 

ALso, looks like you used Shledon Brown's method for chain length installation. It never works, always turns out too tight. If he would have stated to run the chain thru the rear derailleur first. Then pull tight, and add 2-3 links, I would have believed it.

Waves77

I found the issue. The chain is at such an angle that it's rubbing against the screws of the chainrings, causing the "bumps", Not sure what this is due yet...

EDIT: Never mind, that was just the small-small combo putting the chain at a weird angle. Duh.

Michael Angelo 

It's still way too tight in the video.

Waves77

The video is the initial recording, I added 2 links since then, no change at all I'm afraid.

Michael Angelo 

Did you look at the Campagnolo PDF pages 5-6?

https://www.campagnolo.com/repository...AINS_09_11.pdf

Waves77

I'm still trying to figure this out. It does indeed go over the range given in the diagram by a good amount. The chain would have to be really long to accommodate that though, even after adding the 2 links it's not close. The initial big-big measurement of the chain (got it from the Park blog) couldn't be THAT far off could it?

onespeedbiker

The Sheldon Brown Technique/Park is to make the chain as short as possible. Remerber I wrote Does the drivetrain work better on the small chainring compared to the big ring? You will also have to re-adjust the b tension screw. With a short chain the upper pulley will be pulled farther away from the cogs (this is used when someone wants to run a bigger cog than the derailleur is rated) Once you add some more links look at the b adjustment to see if the links corrected the adjustment.

Waves77

@onespeedbiker: Should I not have cut the chain at all? That seems really odd... although at this point I'm starting to think that could be the issue though.

No difference in the drivetrain at all regardless of whatever combination it's in gear wise (which is throwing me off as well).

My girlfriend is comming over in a bit, maybe her phone will record the sounds better. The entire thing just drags and the pulley wheels bump, as if something is out of alignment.

Shimagnolo

In my experience, "too short" is a much greater problem than "too long".

When a short chain causes the lower pulley to get pulled forward of the cassette, (unless you are using a chainring/cog combo that happens to have *no* cross-chain angle), the lower pulley will be moving laterally out of the plane in which the chain is operating. I once set up a Shimano mtn drivetrain where this problem was so bad in the large/large combo, that the chain was being pulled off the side of the lower pulley. That was when I realized the old large/large plus two links rule simply didn't work for some cases.

Take a look at this: https://shell.forethought.net/~ryoder...e-cross-v2.jpg
Note the chain is in the small/small combo, the RD has retracted all the way back to it's stops, and the chain is *slack*. And it doesn't matter! This isn't a combo you use in real riding, and even if you do shift down into it, it doesn't hurt anything.

Waves77

Thanks for the picture, my rear derailleur doesn't retract that far back at all.... crazy, I think I should have not cut it at all. Now to find another Campy chain locally or to wait for one to come in the mail

Waves77

Here's a picture in small-small:

mrrabbit 

On my bike in small/small, the chain will rest just 1/2" below the bottom edge of the upper pulley cagework.

This is viewing from the non-drive side...perhaps you need one more link?

(Not expert...just reporting what I have...)

=8-)

oldbobcat

If your cassette range were wider I'd say lengthen the chain some more, but with your straight block this shouldn't be a problem. Just the same, when cutting a chain I go for the longest length that is short enough to not rub over itself as it passes around the tension pulley. And that's with Shimano.

Ensure that the chain is threaded through the rear derailleur cage correctly. Check chain for stiff or bent links. Then loosen the cable and inner limit screw and "hand shift" the derailleur to feel for positions that run smoothly. If you find them, it's just a matter of readjusting cable tension. If after adjusting cable tension you find it works for some cogs but not all, check alignment of the derailleur hanger.

cny-bikeman

As with most any problematic rear drive train problem I would suggest having the hanger alignment checked and also have a good mechanic check it out and clarify with you what your concerns are. I know I recommend in-person assistance often, but it's a result of comparing the ease at which I can spot an issue in-person vs. relying on someone else's particular verbal or camera perspective. Even after over 20 years experience, I find remote diagnosis for a mechanical problem is not always possible.

cranky old road 

+1 I'm ashamed to admit the number of times I've threaded a chain to the outside of the tab on the pulley cage.