Smallest Chainring on a Campag Triple?

[531c]

Does anyone know if it's possible to put anything smaller than a 30T inner chainring on a Campag triple chainset?

I've got a 30-42-52 triple with a long cage rear mech. I need some really low gears for some touring later this year, and wondered if I could put a 26T or 28T on the front and still shift properly.

Thanks

 

[Will1985]

I *think* the lowest a triple can theoretically take is a 24t inner with the 74bcd (110bcd for middle and outer).

What is your cassette ratio? It makes more sense to change that first unless you are already on 13-28 or 13-29 (9 or 10 speed).

Long cages have a capacity of 39. Your current chain wrap of the chainset is 22, so you want to be looking for a number of <17 in your cassette (lets say you have a 12-25, the CW is 13). Using this logic, a 13-29 will still be fine - the bottom gear would be almost 1:1.

 

[531c]

Thanks Will1985. The cassette is a 13-29, so it sounds like coupling that with a 28T on the front will be marginal.

I'll give it a go, some of the mountains were tough last year even on 30-29 so could do with something a bit lower!

 

[Will1985]

You could try a 28t. You lowest gear has a length of 27.2" according to Sheldon Brown, while a 28t inner would drop that to 25.4". You can go lower still with a 30t rear sprocket from Marchisio which would give you a bottom gear of either 24.5" (28t) or 26.3" (30t)

 

[TheDoctor]

24T inners are available. I used a 24T inner with a 26T cassette up Ventoux, and I'd have liked something even lower.
The shame...