47x17 would put you closer to 75 GI. it's what i run, currently.
48 x 18
But i'm thinking that 47 x 17 is probably round about right - puts you at 72 gear inches. i find that i cant get as much speed on flats as id like, and i could handle a bit more on tough hills............
47x17 would put you closer to 75 GI. it's what i run, currently.