So I'm soon to undergo my first and second SS conversions (Mine and My girlfriends). First question is gear ratio. As I know not much of anything about bikes and I'm just jumping in headfirst I am not sure what gear ratio to use. I pretty much stay in one gear on my 10 speed now and I think the ratio is 40 to 13. However the conversion kit I ordered only comes with a 16, 18, and 20 tooth cog. Forte conversion kit is what I went with. It was kind of on a whim and seemed like a cheap option and I figured I could use 2 of the cogs and save some $. So after looking at some chart on the interweb I found that 40 to 13 is about the same as 48 to 16. Is this correct?

Also, I am having trouble deciding on just running a front brake or using both. I like the idea of only using a front brake just because it looks much cleaner and make the bike a tad lighter. But I'm still not convinced.

Well anyways my Schwinn Traveler is about to undergo an overhaul, be it good or bad depends on me not screwing this up. Any suggestions? I've tried doing as much research as I can but I've found that the only true way to learn something is to experience it. Any advice is much appreciated and try to take it easy on me as I'm just an impatient kid who gets bored too quickly for his limited resources.