Long Cage vs Short Cage Derailleur

The problem is, I read in some areas that this short cage derailleur biggest gear support is a 29T and then I read that the biggest is a 27T. Im getting mixed info on this.

My question is, have anyone of you guys used a cassette with a 28T gear on it with a short cage Shimano derailleur? If so, any shifting problems on the 28T?

Thanks in advance ![/QUOTE]

I run a SRAM 11/28 10 speed on Shimano Ultegra short cage. No problems, sweet shifting.

slyjackson said:

I am building a new bike and I am using a 39/50 double crank and I want to use a 11-28 sram cassette and a Shimano America Ultegra SL RD-6600-G Rear shorter cage Derailleur. Benefits of a shorter cage length from what I have been able to find :

- Snappier shifts
- better chain tension
- less chain slap / greatly decreased drive train noise (!)
- Better obstruction clearance / improved spoke clearance.
- Slight weight loss -- but you gotta be a real weight weenie to appreciate this one.

The problem is, I read in some areas that this short cage derailleur biggest gear support is a 29T and then I read that the biggest is a 27T. Im getting mixed info on this.

My question is, have anyone of you guys used a cassette with a 28T gear on it with a short cage Shimano derailleur? If so, any shifting problems on the 28T?

Thanks in advance !

Get the short cage, it'll work fine even tho the 'advantages' you mentioned aren't something you can feel or see.

The short should be fine, especially with a 39/50 combo.

Peter@vecchios said:

Get the short cage, it'll work fine even tho the 'advantages' you mentioned aren't something you can feel or see.

Glad you commented on the "advantages" of the short vs long cage RD. In fact, except for the slight weight loss, IMO the list is totally bogus. Believe it could be argued that points 2,3, and 4 actually favor the long cage set up. And what is "obstruction clearance" about, unless it's riding through tall grass?

slyjackson said:

I am building a new bike and I am using a 39/50 double crank and I want to use a 11-28 sram cassette and a Shimano America Ultegra SL RD-6600-G Rear shorter cage Derailleur. Benefits of a shorter cage length from what I have been able to find :

- Snappier shifts
- better chain tension
- less chain slap / greatly decreased drive train noise (!)
- Better obstruction clearance / improved spoke clearance.
- Slight weight loss -- but you gotta be a real weight weenie to appreciate this one.

The problem is, I read in some areas that this short cage derailleur biggest gear support is a 29T and then I read that the biggest is a 27T. Im getting mixed info on this.

My question is, have anyone of you guys used a cassette with a 28T gear on it with a short cage Shimano derailleur? If so, any shifting problems on the 28T?

As others have indicated, a short cage rear derailleur will work ... in fact, the long cage rear derailleur will not alter the effective largest cog which can be handled ...

BUT, I would almost always prefer to pay the miniscule premium for a "long" cage ("medium" for you MTBers) rear derailleur than a short cage rear derailleur because dragging a few extra links of chain is a small penalty for being able to swap in a larger cog (e.g., 32t) OR use a crank with smaller chainring (e.g., 34t).

BTW. With regard to the difference in the largest cog which the particular rear derailleur can accommodate according to the "engineer's" specs, Campagnolo used to spec 29t & Shimano used to spec 27t (because of the 11t pulleys they use -- if you want to use a 32t with a Shimano "road" rear derailleur on almost any frame, you just need to change the upper pulley wheel to a 10t). About the only frames where you may have difficulty using a 28t cog with a Shimano 6600 rear derailleur would be those made in the mid-80s (and, earlier!) where those particular frames have a "short" derailleur hanger which was designed to be used with derailleurs which have "vertical" parallelograms (e.g., Campagnolo Nuovo Record).

As far as chain slap, I think that it is a byproduct of having MORE chain than the rear derailleur can handle ... so, choosing a derailleur with a longer cage should actually minimize the likelihood.

alfeng said:

As others have indicated, a short cage rear derailleur will work ... in fact, the long cage rear derailleur will not alter the effective largest cog which can be handled ...

BUT, I would almost always prefer to pay the miniscule premium for a "long" cage ("medium" for you MTBers) rear derailleur than a short cage rear derailleur because dragging a few extra links of chain is a small penalty for being able to swap in a larger cog (e.g., 32t) OR use a crank with smaller chainring (e.g., 34t).

BTW. With regard to the difference in the largest cog which the particular rear derailleur can accommodate according to the "engineer's" specs, Campagnolo used to spec 29t & Shimano used to spec 27t (because of the 11t pulleys they use -- if you want to use a 32t with a Shimano "road" rear derailleur on almost any frame, you just need to change the upper pulley wheel to a 10t). About the only frames where you may have difficulty using a 28t cog with a Shimano 6600 rear derailleur would be those made in the mid-80s (and, earlier!) where those particular frames have a "short" derailleur hanger which was designed to be used with derailleurs which have "vertical" parallelograms (e.g., Campagnolo Nuovo Record).

As far as chain slap, I think that it is a byproduct of having MORE chain than the rear derailleur can handle ... so, choosing a derailleur with a longer cage should actually minimize the likelihood.

Thank you so musch for you input alfeng. I appreciate it.

The parallelogram on the short and long cage derailleurs is the same. This means that (i) rear shifting is identical and (ii) the maximum rear sprocket size is the same for both. The only reason for the long cage on a road derailleur is to provide enough capacity for a triple crankset, not to make any difference to the rear set-up. The only reason for buying the long cage RD is if you might ever want a triple crankset.

- Snappier shifts: BS, as above

- better chain tension: not true, as the long cage RD has a stiffer cage pivot spring to match the longer lever arm

- less chain slap / greatly decreased drive train noise: no

- Better obstruction clearance / improved spoke clearance: which singletrack are you planning on taking your road bike on? With regard to spoke clearance, if your hanger is straight, then the closest approach to the spokes is made by the top of the cage, which is in the same location for both types of RD. If the bottom of your cage is the closest part of the RD to the spokes, then your hanger is bent inwards.