Bruce13

I have a 2013-vintage Seven, still equipped with the Chorus 11-speed it was built up with. Currently running a 11-25 cassette but would like something a little bigger for the hills. I no longer have the specs for that era of derailleur, but measuring the pulleys at 55mm C-C, I'm assuming this is a short cage? If so, could I go as big as 29t? (First post in this forum; probably this is addressed elsewhere but I couldn't find it). Thanks.

noodle soup

29t is correct for the short cage.

Litespud

I'm currently running ~'03 Chorus 10 with a medium cage RD (ballpark measured the pulleys at 73mm C-C). At the time, this was the recommended minimum necessary to run the 13-29 cassette. However, I don't know if the issue was chain wrap capacity or just clearance for the larger sprockets (at the time, the short cage RD had a recommended max chain wrap capacity of 27, which was good for a 53/39 up front and a 13-26 cassette). Possibly the newer RDs have clearance built-in to address the trend toward larger cassettes?

Bruce13

Thanks for the intel, all. I just now found the original literature for the group set! (Took me a while--I've moved twice.) Under "Technical Specifications" are two passages that are relevant:
"Double crankset (52-39 or 53-39) or CT crankset (50-34) + short cage rear derailleur: all 11s Campagnolo sprocket sets."
and
"The 11s front derailleurs are compatible with sprocket sets from 11-23 to 12-29."
No mention of maximum chain wrap per se, but with my compact 50-34 I'm thinking I'm good with a 12-29.
BUT (the next question): weren't changes made to the Campy groups in the mid-teens (2015-ish)? If so, would these changes make any difference, ie, were there changes to the cassette that would make it incompatible with the earlier 11-speed groups? As you know, the Italian stuff with the fancy script is expensive so I don't want to wreck something trying to "make it work".

tomato coupe

Yep, 11 speed Athena/Chorus/Record/Super Record all work fine with a 50/3, 12-29 setup.

dorkypants

I run a 12-30 Centaur 10-speed cassette with a 2019 Veloce medium-cage rear derailleur and a 34x50 Centaur crankset, so you could go larger than 29T with an appropriate rear derailleur.

Bruce13

Good to know. For now, I'm going with the 12-29, but am also thinking there might be a medium cage down the road for me. Thanks!

Marcus_Ti

The cassette is basically the only thing that didn't change. Campagnolo has tried to make everything else incompatible between tiers and years in the last decade....So much so that even they can no longer keep it straight, hence stamping "LETTER" on parts starting in 2015...but only on Chorus and up in that MY.

Bruce13

Ah. So does this mean that if I do decide to get a larger derailleur, it won't be compatible with my pre-2015 11-speed shifters?

DaveSSS 

The 2015+ derailleurs require more cable pull than previous years. If the cable clamp bolt is ground down to the root of the threads where the cable contacts the bolt, it will shorten the lever arm length slightly and improve shifting.

11 speed chorus and above are all 12 speed now. That was my solution - sell off the old stuff and go 12 speed. You might get by with the 11 speed crank and the brakes obviously work, but the rest has to go.

Bruce13

Okay, I've got a new 12-29 cassette and an 11s chain. Usually when I replace a chain I remove the old one, lay it out against the new one, and size the new one to match. But in this case, I'm adding two teeth on the big cog (old cassette is a 27, not a 25 as previously stated). Do you think I'll need to add a link or two?

noodle soup

I use method 3 to determine chain length(starts at 4:01).

Bruce13

Okay, will check it out. I have sized a chain from scratch before but was wondering if there was a rule of thumb, like, since I added two teeth, add a full link, etc.. Thanks!