# 13-29 Campagnolo Centaur 53/39 - short cage ok?



## acid_rider (Nov 23, 2004)

greetings. posting on behalf of my shy riding buddy.

he has Centaur 2006/2007 vintage, 10-speed, 53/39 & 12-25.

wants to do some hills and been recommended 10-speed 13-29 Campag (Veloce) rear cluster to make the hills work easier. 

BUT he has a standard short cage derailleur right now.

will this short cage be ok to handle 13-29 with 53/39 front rings with Campag Centaur?

thanks in advance


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## sokudo (Dec 22, 2007)

Officially, 13-29 needs a medium cage rear derailleur. Short cage derailleur specification claims 27 teeth capacity and 26 max cog size. However, compact 50-34 with 13-26 is officially ok, and that is 29 teeth capacity. Finally, there are people who are happily running 29 on 53-39 with short cage.

He can try to set up a new cassette with his current derailleur, and if that does not work, he can always switch to a medium cage. And if 13-29 is not enough help for the hills, switching to compact is the next step.


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## acid_rider (Nov 23, 2004)

thanks Sokudo. 
what do you mean by "try it and if it does not work..." - what exactly will not work for him to keep an eye on? cross-chaining etc?


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## Bianchi67 (Oct 16, 2005)

I have used a 13/29 and 53/39 with a short cage deraileur on several bikes without any issues. Be sure to check the big-big combo while in the repair stand to be sure the current chain is long enough.

If it is going to be permanent, get the medium cage and longer chain.


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## stlutz (Jan 6, 2005)

I ran that combo on one of my bikes for several years and everything worked great.


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## foz (Sep 30, 2004)

I've also been running that exact same combination on and off for a while, with absolutely no problems at all. If the chain is set correctly for 53x13, then the mech will have no problem with the 29.

foz


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## C-40 (Feb 4, 2004)

*not always true...*



foz said:


> I've also been running that exact same combination on and off for a while, with absolutely no problems at all. If the chain is set correctly for 53x13, then the mech will have no problem with the 29.
> 
> foz


Not all bikes will work the same with this setup, due to differences in chainstay length. If your frame has the perfect chainstay length, up to 2T of wrap can be gained, compared to a length tat is a little longer or shorter.

The chain length should not be set in the 53/13. The maximum wrap capacity is insured by making the chain as long as possible in the 39/13. As long as the chain does not hang loose or rub on the upper chain guide of the RD cage, then it's not too long. The way to double check the length is to wrap the chain around the big ring and largest cog, but not through the RD. Bring the ends together, then add 1 inch of chain. If that length is 1 inch longer, then the chain would hang loose in the little/little combo when it's long enough to wrap the big/big.

To the OP, it will work for certain, if the bike is never accidentally shifted into the 53/29. Most people don't to risk damage, but the only way to know if it will work is to gently shift into the 53/29 on the work stand. If the chain is really too short, it will probably refuse to shift. If that's the case, then you have your answer. Check the chain length first, by the methods I've described.


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## foz (Sep 30, 2004)

I meant to say 39x13, not 53x13.... mental slip there on my part:blush2:


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## acid_rider (Nov 23, 2004)

thanks everyone. I think I will print it and have my buddy take to his shop to ensure the LBS mechanic is informed. We both avoid cross-chaining so 39-13 or 53-29 will not used, at least not deliberately 8^)


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## acid_rider (Nov 23, 2004)

*chainstay length*



C-40 said:


> Not all bikes will work the same with this setup, due to differences in chainstay length. If your frame has the perfect chainstay length, up to 2T of wrap can be gained, compared to a length tat is a little longer or shorter.
> 
> The chain length should not be set in the 53/13. The maximum wrap capacity is insured by making the chain as long as possible in the 39/13. As long as the chain does not hang loose or rub on the upper chain guide of the RD cage, then it's not too long. The way to double check the length is to wrap the chain around the big ring and largest cog, but not through the RD. Bring the ends together, then add 1 inch of chain. If that length is 1 inch longer, then the chain would hang loose in the little/little combo when it's long enough to wrap the big/big.
> 
> To the OP, it will work for certain, if the bike is never accidentally shifted into the 53/29. Most people don't to risk damage, but the only way to know if it will work is to gently shift into the 53/29 on the work stand. If the chain is really too short, it will probably refuse to shift. If that's the case, then you have your answer. Check the chain length first, by the methods I've described.


C-40, the geometry for my buddy's bike says that chainstay length is = 410mm. What do you think? Also what is the risk if he accidentally shifts into 53-29 or 39-13 ?
thanks.


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## C-40 (Feb 4, 2004)

acid_rider said:


> C-40, the geometry for my buddy's bike says that chainstay length is = 410mm. What do you think? Also what is the risk if he accidentally shifts into 53-29 or 39-13 ?
> thanks.


The 39/13 is not a problem, but you don't want the chain hanging loose in that combo. If the RD has insufficient wrap and chain length, then shifting into the 53/29 could damage the RD, or perhaps snap the chain.

As for chainstay length, set the bike up and see how it works. You can put numbers into a chain length calculator equation, but I'm not sure that they would accurately predict the perfect length. 2T of wrap is 1/2 inch of chain or 1/4 inch of chainstay length difference. Chains can only be changed in length by 1 inch increments.


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## eddie m (Jul 6, 2002)

I've been using a short cage with a 53-39 X 12-26, and a 50-34 X 12-25 on 2 different bikes, and that works fine, and I think at least one of those would work with your combination. As c10 said, what you can get away with in terms of over the limit tooth differences depends on the exact chain stay length. You might also get some extra capacity by changing one or both of the derailer pulleys to 11 teeth, but I've only found expensive ceramic bearing pulleys that would fit Campy. The other downside of a short cage with a 29 is that you need to adjust the derailer away form the cogs to get clearance on the 29, which has to hurt shifting performance,

em


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## PlatyPius (Feb 1, 2009)

It will technically work, but it is far from ideal. Why even take the chance? Especially if we're talking about a bike that could have the stays broken off if the combo decides to not work? If the derailleur contacts the cogs, it can jam or get thrown into the spokes, causing it to break off the derailleur hanger, take out several spokes, and then possibly lock up the rear wheel and break the seat & chain stays (if the bike is carbon). I've personally seen it happen 3 times in the past year. (or, the results rather...when they brought it into the shop in pieces.)

A new rear derailleur is cheaper than a new frame, wheel, derailleur hanger, etc. Yes, it CAN work, but I wouldn't feel safe taking the chance.


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## eddie m (Jul 6, 2002)

I wouldn't use a combination that didn't allow me to shift to the big-big combination, or that allowed the chain to droop on the small-small combination, but with that caveat, the risk of breaking something is pretty small if you adjust everything correctly. It doesn't cost anything to try something, you can always replace the derailler if it doesn't work well enough for you.

em


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## bing181 (Oct 17, 2005)

On 3 bikes with a 13-29/39-52 (or 53) combo and short cage rear, I've had one that worked perfectly, one that worked terribly (constantly jumping and miss-shifting) and one that was somewhat in the middle. 

Not strictly OK, as you know, but try it and see. I wouldn't go standing up too often till I was sure though ...

B


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