Campagnolo 13-29 cassette compatibilty

Quoted post said:

Originally posted by cmcdonnell
Hi,

Will a 13-29 Record 10 speed rear mech work with a short arm mech? I am sure that when the Chorus 10 speed was reviewed a couple of months ago the reviewer said he had used it. I usually use a 12-25 cassette but would like to use a 13-29 for a couple of weeks in the Alpes. Can I just put it on and avoid using the 23/26/29 in the big ring?

Looking at the medium cage rear mech, the disance from the frame mounting bolt to the upper roller is the same between the short cage nad the medium cage so I can't see why campagnolo quote a 26T as the max sprocket for the short cage and a 29T for the medium.

And even on my friends medium cage rear mech, if you back pedal in the 39/29 the sprocket touches the upper derailluer roller but it is OK when you forward pedal.

Also, if you use Campagnolos formula for working out capacity (A-B)+(C-D) where A is the big chainring, B is the small, C is the largenst sprocket and D is the smallest. you would get a capacity of 27 for a 53-39 with a 13-26 which would be ouside their tolerances

I am guessing that when you work out capacity it needs to take into account the extreme gears you would use i.e 52/26. However when I put it on I was concerned thet the upper roller on the mech touches the cassette when you back pedal although not as you forward pedal. The chainlength was set in the 39-12 and just clears the upper roller.

Thanks

Chris

You are taking a risk in the big/big ring/cog areas as well as the small/small. Chain wrap on a medium or long cage will provide for allowing all combinations without ripping your rear derailer off or having your chain go slack.
However, if you are willing to risk it and can stay away from those cross chaining combinations, and use a chain length appropriate, you can do it.

Quoted post said:

Originally posted by cmcdonnell
Hi,

Will a 13-29 Record 10 speed rear mech work with a short arm mech? I am sure that when the Chorus 10 speed was reviewed a couple of months ago the reviewer said he had used it. I usually use a 12-25 cassette but would like to use a 13-29 for a couple of weeks in the Alpes. Can I just put it on and avoid using the 23/26/29 in the big ring?

Looking at the medium cage rear mech, the disance from the frame mounting bolt to the upper roller is the same between the short cage nad the medium cage so I can't see why campagnolo quote a 26T as the max sprocket for the short cage and a 29T for the medium.

And even on my friends medium cage rear mech, if you back pedal in the 39/29 the sprocket touches the upper derailluer roller but it is OK when you forward pedal.

Also, if you use Campagnolos formula for working out capacity (A-B)+(C-D) where A is the big chainring, B is the small, C is the largenst sprocket and D is the smallest. you would get a capacity of 27 for a 53-39 with a 13-26 which would be ouside their tolerances

I am guessing that when you work out capacity it needs to take into account the extreme gears you would use i.e 52/26. However when I put it on I was concerned thet the upper roller on the mech touches the cassette when you back pedal although not as you forward pedal. The chainlength was set in the 39-12 and just clears the upper roller.

Thanks

Chris

I'd size it for the big/big and if there are wrap capacity issues just stay out of the smaller cogs when in the small ring. Sizing it small/small is the wrong way to do it when you are exceeding the derailers stated capacity.