Medium or Large Cage Rear Derailleur?

[jimithng23]

Huh, that's odd. The Specialized specs show a 3x9 setup with a long cage. Again, not sure what your gearing is so if you're not a 3x9 you're prolly ok.

A medium cage has a 37T capacity whereas a long cage can handle 45T. Let's say you're a 2x9 with 11-34 rear and 22-32 front. You got 23T spread on the rear and 10T spread on the front for 33T total spread, so a medium will work. A typical 3x9 with 22-32-44 front will have 22T front (added to the 23T rear) for 45T total, so you need a long cage. A 3x9 could only shift up to the 15 tooth cog with a medium cage derailluer which would make the big ring pretty much unusable IMHO.

Rg.

that's an awful lot of math on a Sunday morning...sheesh