I've just built a new Campy compatible wheel that I'm going to use with my Chorus 10sp setup. My crank is 50/36 and I have a short cage derailleur. My current wheel has a 13-26 cassette and I'm thinking of going to a 13-29 as I'm getting older (55) and my hill climbing days are long past.
Will the combo work with what I have, or will the derailleur not handle it. Normally I'd just try it but Campy cassettes, even the Veloce and Centaur, are pricy compared to the Shimano and I don't want to spend money on something I can't use. I'm not going to change the derailleur so if it won't work I'll just get another 13-26.
And if I do this, will I need to add another link pair to the chain?
'''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Your chain length must let the bike shift to the big-big combination. It's not a combination you should use but, if you ever use it accidentally, the results can be extremely damaging if the chain is too short. So, yes, you will probably have to lengthen the chain. For that matter, you will likely need a new chain if you install a new cassette of any configuration to avoid skipping.
That said, your short cage rd will probably not let you use the small-small or even small chainring-second smallest cog as it will not wrapup enough chain to keep any tension. However, the concequence of shifting into either combination is just noise, not damage.