campy 10 sp cassette question
 

Hi,

Just replaced a Chorus 10 sp cassette. Originally had 12-25, went to 11-15. I noticed a rattling coming from the top sprockets (21,23), especially using the large chainring (50 tooth, compact crank) that didn't used to be there.

Reading the tech specs, I see that the spacers between the cogs is different between the 12-25 and the 11-25. Does this explain the rattling? Why are the spacings different? How to make the rattle go away?

Thanks!

You aren't supposed to be cross chaining anyway dude.

first off, i assume you mean 11-25. secondly, if there is any play when the lockring is tight, you need an additional spacer

yes, I meant 11-25.
I avoid cross chaining large large and small small, but I have used the second cogs in from the ends. Am I not supposed to do that?
There is no play in the cassette. If the stack height is differrent, I'll need to adjust the limit screws and cable tension...
I got the part about unique upper and lower jockey wheels beigh different, and having directional orientation.

Seems quieter this morning - did I have a break-in period yesterday on the hills?

re-torque the cassette.

How old is the drive-train, especially the chain? A worn chain could be noisier on a new cassette than on the old one. If it continues, consider replacing the chain.

BTW, cross-chaining is fine. Might be a bit noisy and require slight front der. adjustment, but it's not going to hurt anything. Don't let the gear-nazis run your life. :D

The chain is new with the cassette. I will retorque. That knurled lockring ought to prevent loosening...

Hmmm, a puzzle...

A few shots in the dark: when you retorque the cassette, be sure and clean/re-grease the splines on the freehub body so the cassette sits as far in as it's supposed to.

The only other possibility I can think of is that the rear der. is slightly off with the new cassette, and could use a small adjustment.

Ok - I'll remove, clean and regrease the freehub, and reasssemble, with any required rr der adjustment (I didn't regrease the first time - everything seemed to fit well enough)
I do not have a torque wrench, The campy lockring says torque to 50Nm. I guess that's a "firm press" with a 12 inch cresent wrench and a chain whip. My friend says the tire stores torque the lug nuts to 80Nm.

BTW, is there a requirement to lube the freehub in any way? everything is sealed.

Freehub shouldn't need internal re-lubing unless it's time for general hub maintenance, and that depends on mileage, riding conditions, and so forth. Maybe once a year or so? I always use a light film on the splines, then slide the cassette on and call it good. If there's muck on the inside end, it *might* effect the cassette spacing, but I think this is a long shot.

As to torque, 50Nm is *tight*, just about as hard as you can crank on the 12" wrench while holding the cassette with chainwhip. Hard to over-do it, unless you're stupid strong, or use a vice to hold the lockring tool or something. You should feel the teeth on splined side of the lockring kind of "ratchet" as you cinch the lockring down that last turn or so.

I also assume from what you've said that you've got the correct lockring, and all the correct spacers in the correct order, as per p. 77 here: http://www.campagnolo.com/repository...s08_B_1007.pdf

If the cassette is tight, then the rattle noise has to be der./chain related.

Hope this helps...

yup - got all that.
Is there something that replaces the "b screw"? Over on Mechanics forum they are talking about a worm gear on the jockey wheels...

Thanks for all your input so far!

IMHO, that's way too tight for the retainer. I take the removal tool and use it to hand tighten the retainer, then I take a 1" closed wrench, and tighten about 1/3 turn. That's it. I've run into guys who overtighten the retainer, lot's of luck removing it next time you want to service it.