Road Bike, Cycling Forums banner
1 - 17 of 17 Posts

· Squirrel Hunter
Joined
·
3,854 Posts
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.
 

· Registered
Joined
·
10,161 Posts
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.
 

· Registered
Joined
·
35 Posts
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.
 

· Registered
Joined
·
507 Posts
Discussion Starter · #8 · (Edited)
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.
 

· Registered
Joined
·
26 Posts
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.
 
1 - 17 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top