cazeloof

Hi people. I have been looking at this interesting forum for some time and this is my first post (I m originally french speaking so sorry for the coming mistakes in english...)

I will probably buy a second hand bike from a friend, and that bike comes with a full Campagnolo Veloce group, and the classic 53/39 - 12/25 combo.
My plan for this summer is a trip in the french alps with many climbs so I think I ll be a bit "short" with the 39:25. My former bike had a triple.

So my question is the following: is it possible to buy a 13/29 campy cassette as I ve seen they exist, and keep the rest of the group, including the short cage rear derailleur ?
I think the 39:29 should do the job in the french cols, and I could put back the 12-25 when back here in Belgium to have something more "balanced". I just want to know if it is technically possible.

Thanks

DaveSSS 

Using a 13-29 with a short cage will work fine in you never shift into the 53/29. If you make the chain long enough to wrap the 53/29, it may hang loose in the 39/13 and maybe even the 14 or 15.

How well this works depends on the chainstay length and the RD hanger length. The perfect chainstay length can gain an additional 3T of wrap capacity, compared to the worst case. The longer the hanger, the greater the chances are that the upper jockey pulley on the RD will not touch the 29T cog when you're in the 39/29.

This question gets asked often and people say it works fine on their bike, but that does not mean it will work the same on every bike.

The bottom line is all you can do is try it. It if doesn't work, you can always get a cheap Veloce medium cage RD.

Jay Olson

Officially, the maximum rear cog size with a short cage derailleur is 26T, and you need a medium cage to go up up to 29. I have no experience with running a 29T cog on a short cage derailleur, but other people have done so. It might depend on the length of your chainstays, you probably would need a longer chain, and you certainly shouldn't use the extreme cross-chained combinations (53x29 and 39x12).

Years ago, someone told me that you should always buy the medium cage Campy derailleur if you have a choice. It shifts just as well/fast as the short cage version, and is more flexible if you want to run a larger cassette or even a compact crankset. With this in mind, you could pick up a new Veloce medium cage derailleur from Ribble for $50 or so (or cheaper for a used or older year model), sell the existing short cage derailleur, and not really be out that much money.

ptle

Have you thought about swapping out the chainrings?

cazeloof

Ok thank you for the advice, I think I will go for the 13-29 solution. I don't see why I would use such combinations as 53:29 (who would do that ?).

ptle, I don't think I can put a smaller chainring than a 39 on that type of crank. I could change it for a compact, 50/34 would be a nice solution too but It seems a lot more expensive. And I only ride really hard climbs once or twice a year.

knobster

I had this setup on one of my bikes and it worked fine on a short cage Campy rear derailleur. I did end up switching to a medium cage RD later so I could use the 52 with the 29.

DaveSSS 

The 53/29 is not a combo that would be normally used, but it could casue damage if you shifted into it by accident with a chain that's too short. Some people take that risk.