One question no one is asking, what shifters do you have? Are you planning on buying new shifters as well? If you have shimano shifters the SRAM won't work.
Oh yeah, I'm for SRAM all the way. After riding Shimano for years and riding SRAM for one year I have no intentions of ever buying another Shimano shifter or derailleur. I just like SRAM better. It's all personal preference though.
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I may be fat but I'm slow enough to make up for it.