just stick with 48:16 'til you get out here and see what you think. i ran that same ratio for years here in the springs, with never a need to go up or down. if i had to live to boulder, i'd probably run 48:16 there too. i do have 40:15 on my conversion, which i use more for cruising around. i sometimes ride my race ratio of 50:15 around town, but it can be a workout in the hillier parts of town... unless of course you're a MAN and live in "breck" and ride your 49:15 fixie to starbucks and back to look cool and wait for the next fad.