Derailleur Size ?

[R&R]

Hi, can anyone tell me how does one know what size derailleur to purchase : long, mid, or short.

Tks.

 

[daveornee]

Hi, can anyone tell me how does one know what size derailleur to purchase : long, mid, or short.

Tks.

You must make sure it matches the range of cogs and chain wheels you use.
Max Sprocket ?T
Min Sprocket ?T
Front Difference ?T max.
Total Capacity ?T

T is the number of teeth on cogs and chain rings.
Longer increases everthing except Min Sprocket.
It is usually better to error on the side of too long than too short.