Currently I'm running a 46x18 setup for hills, just because it's what I started with when I first started riding fixed 3yrs ago. It was ok at first but the weak 67.2 GI became annoying with how it tops out on flats (let alone downhill). I couldn't stand it so I picked up a cheap 15t take-off that I came across, but the 80.7 GI was too extreme for me on even moderate hills, so I went back to the 17. It's unbearable now, so trying to figure out what to do.
I'm gonna try out a 17t cog b/c it nearly doubles the skid patches, from 9-->17. I still need to be able to tackle moderate hills, but want to better keep up with friends on geared bikes on the flats/downhill.
Not sure if the 71.2 GI would be enough of a change for me? Or should I go with a 47t that makes it 72.7 GI or a 48t 74.3 GI?