Long and short cage derailleurs- whats the diffs?

[Yang]

I'm looking for the the pros and cons of a short cage versus a long cage rear derailleur. You can get the options for Campy Record.

[nellie]

one is long and the other's short...?

[Mudsimus]

Long cage for tripple short cage for normal cranks.

[Mudsimus]

one is long and the other's short...?

 

Getting there Nellie. Just keep going sunshine!

[nellie]

one is long and the other's short...?

 

Getting there Nellie. Just keep going sunshine!

 

[Spinnekop]

Like Muddy said.

 

Long cage for the hard to reach triple front.

Short for the normal setup.

 

Would one go for a long cage if you have a 42 blade at the back like Man with no Name?

 

 

Spinnekop2008-11-19 05:54:56

[barrykm]

Campy has specific RDs for it's Triple range.

 

Are the long and short RDs perhaps not to do with the different requirements of regular and compact carnksets?

[Dirtbreath]

All derailleurs have what is called capacity. The longer the cage the higher the capacity, ie the greater the range that the derailleur can handle. If you search the manufacturers webiste they will give you a table of compatible gearing and the capacity that that particular derailleur has.

 

I used to have a Shimano table that explained this better but I cant seem to find it.

 

[Mudsimus]

Campy has specific RDs for it's Triple range.

 

 

 

Yes. Long cage RD's. Compact doesnt need specific RD's.

[Dirtbreath]

Care of "the late" Sheldon Brown:

 

"In selecting a rear derailleur, the

first consideration is how wide of

a gear range it will be required to shift.

Most 10-speeds have the same high gear

(52 teeth on the front with 14 on the

rear). The major difference between

types of gearing is in how low the lowest

gear is and what kind of spacing is used

in between.

 

 

Derailleurs usually are rated in terms

of "tooth difference capacity," a number that represents the derailleur's capa

city to take up slack in the chain. To

find the minimum tooth difference capacity needed for the gearing you have se

lected, subtract the number of teeth on

your smallest rear sprocket from the

number of teeth on the largest. Do the

same for the front sprockets, and add

the two numbers. For example, if your

rear sprockets run from 14 to 26 teeth,

the rear difference is 12. If your chainwheels are 36-52, the front difference is

16. Ad ding the figures for front and rear,

we get a total difference of 28 teeth. If

you get a derailleur with a 28-tooth capacity or inore, it should handle the range.

If you use a derailleur with insufficient

tooth difference capacity, the chain will

be too slack in some gears or too tight in

others and you probably will not be able

to get it to shift properly."

Dirtbreath2008-11-19 06:07:52

[barrykm]

Campy has specific RDs for it's Triple range.

 

 

 

Yes. Long cage RD's. Compact doesnt need specific RD's.

 

Thanks

[blingking]

in terms of XC racing, i imagine that a long cage is better?

[Mudsimus]

in terms of XC racing' date=' i imagine that a long cage is better?[/quote']

 

Most of the time. If you run a 32 at the back you can use a medium cage. Short cage is not advisable for mtb.

[Dirtbreath]

Shimano XTR long cage has a cpacity of 43. Short cage is 33.

[Super_mil]

Check out http://www.beyondbikes.com/bb/tech/?section=rdr

[Yang]

Solomon's at the 94.7 show was offering the Record long cage derailleur and the Record ergo levers for R4000. I left it. They would still send it to me if I changed my mind.

 

I take it from the posts then that the long cage isn't the most suitable for a road bike cassette running off a double chain ring, and I should therefore stick with the short cage?