cage length is determined by your crank and cassette. you take the difference of crank teeth and add those to the difference of cassette teeth to come up with a total capacity. different caged deraillers have different capacities. the medium cage X-0 has a capacity of 37 teeth, while the long cage has a capacity of 45 teeth. so if you have a 22-32-44 crank and 11-32 cassette, that is a capacity of (44-22) 22 + (32-11) 21 = 43 teeth, thus you would need the long cage derailler, as that combination of crank and cassette would exceed the capacity of the medium cage RD.danK said:Which do I need?
I'm running an xt compact crankset and an xt cassette, but forget which on:
If it's the 34, I want the long?
If it's the 32, I want the medium?
Or am I mistaken?
I'm at work and can't remember which I have, hence the general inquiry.