# 13-29 and a short cage derailleur



## RoyIII

I know the specs say to use a medium or longer cage on a 13-29, but won't a short cage work, too?


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## Keeping up with Junior

*Yes*



RoyIII said:


> I know the specs say to use a medium or longer cage on a 13-29, but won't a short cage work, too?


Yes, my wife uses one occasionally when we head somewhere with steep hills. Just dont cross chain and make sure your chain is long enough. If for regular use you might want to get the derailler but for occassional use the short is fine.


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## C-40

*more...*

If you never shift into the 53/29, then it will most certainly work. Make the chain as long as possible, just so it doesn't hang loose or rub on the RD in the little/little combo. 

Chainstay length also has an effect on the success of this combo. There's a 2T wrap "dead zone" (1/2 inch of chain). If you just happen to have the perfect chainstay length, then you may have a little more wrap capacity.


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## RoyIII

Thanks, guys. I thought so but wasn't sure.


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## tjjm36m3

I thought by using a short cage RD with 13-29, the only problem would not able to use the small chainring with smallest sprockets?


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## UcannotBsirius

I normally run 39/53 with a 12-25 cassette. However I keep a spare 13-29 cassette and chain cut longer to suit for the rare occasions when I need lower gears (vists to the Alps etc). Use them with both a Centaur and Chorus short cage rear mech with no problems at all or deteriation in shifting quality. I wouldn't want to use 53x29, though the chain I use is long enough to cope if I select that by mistake.


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## gradosu

anyone know the 'official' campy chainring/cassette tooth spread that the short, medium, and long cage derailleurs can handle?


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## RoyIII

Here is the explanation at Branford Bike:

Rear Derailleur Chain Wrap Capacity (CW) Easily Explained...
Campagnolo officially recommends various rear derailleur cage lengths for use with specific cassette and double or triple chain ring combinations. However, it is important to understand that any 1999 to current, Campagnolo 10 speed rear derailleur, will shift up to a 29 tooth cog and down to an 11 tooth cog. The problem you will run into is that the derailleur cage may not be long enough to take up all the slack in the chain for a wide range. Thus Campagnolo recommends using a short cage derailleur with a maximum cassette cog size of 26 teeth even though it will shift to a 29 tooth cog. Chain wrap or CW is a helpful concept to understand when you need to determine proper derailleur cage length.

Current Record, Chorus, Centaur and Veloce 9 and 10 speed rear derailleurs use the same three cage lengths; 55, 72.5 and 89 mm measured from the center of the upper jockey wheel to the center of the lower jockey wheel. 55 mm cages have a chain wrap value of 27; 72.5 cages have a CW of 36 while 89mm long cages have a chain wrap value of 39.

Chain Wrap is a simple calculation that will help you determine whether the rear derailleur you choose has a long enough cage to take up the chain slack in your drive train. The shorter the cage, the lighter and stiffer the derailleur and the quicker it will shift. Calculate Chain Wrap to get the greatest shifting performance.
To calculate Chain Wrap Capacity determine the difference between your largest and smallest chain ring. Then determine the difference between your largest and smallest cog. Add the differences and you have Chain Wrap Capacity.

Example: 42/52 chain rings and a 12/21 cassette yields a CW of 19. 52 - 42 = 10. 21 - 12 = 9. 10 + 9 = 19. So, with a 42/52 chain ring and a 12-21 cassette you would need a rear derailleur that has a Chain Wrap Capacity of at least 19.
For a 39/53 and a 13/26 combo you will need a minimum CW of 27. 53-39 = 14. 26 - 13 = 13. 14 + 13 = 27. In practice the CW numbers are flexible by one or two points. You could use a 39/53 with a 12-26 cassette with a CW of 27 even though the calculation calls for 28.

The campy record instruction book at the campy site says a short cage works for all but 13-29.


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## gradosu

The manual also says that a short cage works with a compact crank and any cassette except the 13-29. so, that would be 16 + 14 = 30. So, the 27 chainwrap value for short cage is conservative?


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## RoyIII

I think so, yes. I am using a short cage chorus rear der with a 13-29 right now and it works just fine.


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## gradosu

oh right on. So a compact and 11-25 should work just as well. Thanks for the help


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## RoyIII

I think if you get the chain length just right - not too long - it works OK.


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## nismosr

Can I use a Medium Cage Record RD on a 13-26 cassette and compact crank 50/34 setup ? or Short cage is much better ?


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## David Loving

13+16= 29 chainwrap. I'd use a medium if you got one (36 max), but the short cage is just 2 over its recommended max of 27.


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## weiwentg

Old thread, but I wanted to report that with 407mm stays and a 53-39 front, a short cage 10s rear derailleur (Record) works with a 13-29. No issues in the 53-29, not that you should be in that gear a lot.


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## jan erik

Allso,you could end up with a too short chain...


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## tztag

I've used campy short cage with 30t chain wrap a few times and as long as you set the chain length correctly it will shift in any combination safely. Even as far back as 8 speed the shift cage will do 30 teeth.


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