I am getting parts together to build a Spider 29r. Question about the rear D? What is the determining factor on whether to get a small, medium or large cage? Is it just preference, clearance? :?:
how many rings you run up front, and how much the chain grows, for a fs, 3 rings large. 2 rings medium, 1 ring short
This is the simple answer. Technically its based on capacity. To determine you determine difference in teeth for font biggest ring and smallest ring. Then same thing for the cassette, then add those two numbers together (biggest ring - smallest ring) + (biggest cassette cog - smallest cassette cog). You need a RD with a total capacity greater then this number.
