Originally Posted by
spectastic
I have a short commute of 3 miles, and my town is relatively flat, and I basically never change gears unless it's really windy or really hot. I was wondering what it would be like to ride with a singlespeed. After some intense gear counting, I determined that I typically use the ratios 52:15 (for 700c) and 52:18 (for 27"). But I also realize that ss cranks are a lot smaller, so I'm hoping to get some suggestions for the gear ratio.
This is what I don't get: the diameter difference between a 27" and a 700C wheel is much smaller than the gear ratio difference between a 52:15 vs. 52:18.
That said, as a longtime SS cyclist (feel free to call me a singlespeed fanboi), I think that the lower gear ratio of the two, 52:18, would perhaps suit you better for riding across town, because of the frequent stop-start situations. You'll appreciate the better acceleration. If your commute where 10+ miles with little to no traffic (or traffic signs), I'd suggest the higher.
Regarding cranks: I've always used 172.5 cm or 175 cm cranks on my SS bikes. You'd need shorter cranks (I assume) if you were riding fixed gear, for safer cornering. An experienced fixed gear cyclist might correct me, if I'm wrong.