Campag4life

I have over 5K miles on my '06 Campy Chorus QS rear derailleur now and have started to hear a feint clicking from the rear rollers. I have tried to tune this out by trimming the derailleur to change the loading of the little cogs (rollers) on the derailleur and have also lubricated the rollers and adjusted the H screw to change amount of chain wrap but the feint clicking continues. My chain is below .75% stretch and cassette is in good shape. The derailleur shifts OK and chain doesn't slip even when mashing out of the saddle.

My question is...feeling the axial play in the two rollers...they are fractionally different size...see below Campy PDF...the top roller has a lot more play in it than the bottom roller. The top roller takes the load of course for shifting gears and no doubt there is some play built into this little wheel but the question is how much and what is acceptable? Should the amount of top and bottom roller play be the same?...if so, the top roller is quite worn on my RD. I am suspecting that the top roller bearing is worn out, causing the roller to wobble within the chain links and inducing this feint clicking.

Does anybody know where I can order replacement rollers for this rear derailleur? I am presuming that the roller and bearing are integral or sold that way but not sure if the little bearings are available separately.

Any advice would be appreciated.
Thanks.

DaveSSS 

The top pulley is supposed to have more axial play than the lower one, so that's normal. The pulleys roll on bushings that are not replaceable. If you have a problem, you replace both pulleys as a set. Any store that sell Campy should have them. Peronally, I lube the pulley bushing with light oil or a spray lube, every time I lube my chain. The bushing will last as long at the pulleys if you keep them lubed.

https://www.excelsports.com/new.asp?p...endorCode=CAMP

You might want to do a search on chain wear. If that .75% value comes from a chain checker, it's not accurate. A 12" precision rule is what's needed to measure elongation. If you have a Campy chain and actually measure over .5% elongation with a rule, the chain might be very worn out, or at least is was poorly maintained.

I've used Campy chains for 6,000 miles and measured .2% elongation. That does not mean the chain was is good shape. The rollers were worn out and the side wear excessive after than many miles. A second new chain, installed on the cassette, skipped on the 19T cog, indicating that the chain should have been replaced sooner.

A chain should never just start skipping unless it's used far, far too long, with elongation in the 1.5-2% range.

DaveSSS 

oops, double post.

Campag4life

Thanks for your excellent advice Dave. I appreciate the perspective on what is normal relative to the little roller wheels as well....top having more axial play by design. I have a precision rule and will measure a longer length of chain as you suggest. I understand your suggestion...minimizing measurement error so makes sense.

That link is just what I was looking for to purchase small Campy parts...awesome. I need to be more vigilant about oiling the roller bushings when oiling my chain.

You offer a lot of great advice Dave to the forum here and again my thanks.
Hope you got out for a long ride this Memorial day.