[Allez Rouge]

I have a line on a NOS LeMond road bike in my size. It's a 2.5 hour drive away so I've not seen it yet.

The bike comes stock with a Centaur rear der, and a 12-25 cassette. Being old and slow and Clydesdale-ish, I'd like to switch to a 13-29 cassette.

I've no experience with Campy. Given the stock 12-25 cassette, is it likely the rear der is a short-cage? If so, will it handle a 13-29?

If not, what are my options? Can the rear der be converted to a longer cage? Is there another cassette that might work?

Any and all input will be much appreciated.

 

[euro-trash]

It is likely a short-cage. If your chain is long enough you can run a 13-29 on a short cage IF you stay out of the big-big combo.

Veloce mid-cage rear mech aren't too expensive if you decide to make the switch.

 

[Kerry Irons]

Yup

It is likely a short-cage. If your chain is long enough you can run a 13-29 on a short cage IF you stay out of the big-big combo.

Veloce mid-cage rear mech aren't too expensive if you decide to make the switch.

Also, you can get just the medium or long side plates for the idler cage (Branford Bike). They're pricey, but possibly cheaper than a new derailleur. If it were me, I'd just put it together and see how it works - staying out of the 39/29 would eliminate the need for the longer cage.

 

[Allez Rouge]

Kerry, you lost me. (Never a great trick, of course.)

If it were me, I'd just put it together and see how it works - staying out of the 39/29 would eliminate the need for the longer cage.

Um, but wouldn't that also eliminate the whole point of swapping to the 13-29 cassette?

Instead of 39/29, did you mean 53/29?

 

[Spunout]

It will work with the short cage, and it will work in the big-big combo but you must make sure that your chain is long enough.

Kerry typoed above, he meant 53/29.

FWIW, I run campy on the racing bike and have a short cage RD. 53/39 up front and I run everything from an 11-23 to a 13-29 with one chain length. I can run all big-big combos and never run out of chain wrap when in a 39 11, 12, or 13.

I might just post pics someday.

 

[JP]

Yeah, with the right chain length, one can use 39/53 with 13/29. I still have tension in small-small and enough slop for comfort in big-big. Not that anyone would use those combinations. It's just the ticket for me right now. I also will try to post pics

 

[Kerry Irons]

Yep, typo

Instead of 39/29, did you mean 53/29?

You betcha.

 

[weiwentg]

It is likely a short-cage. If your chain is long enough you can run a 13-29 on a short cage IF you stay out of the big-big combo.

Veloce mid-cage rear mech aren't too expensive if you decide to make the switch.

I might be off base here, but I remember Centaur/Daytona used to come in medium or long cages only. if you want to ask the seller to break out the tape measure, short cage is 55mm from upper pulley axle to lower, medium is 72.5mm. 2005 Centaur has S, M and L. medium can handle 13/29 with a double or 13/26 with a triple, long can do 13/29 with a triple.