Originally Posted by
AngryScientist
if it is in fact fairly flat where you live, you may surprise yourself and be happy with one gear ratio. i am always pleasantly surprised at just how much i can push one gear. it may take you a few iterations to find your ideal gear ratio, but its cheap and easy to swap cogs. add to that, you can get a fixed/fixed rear wheel and be able to quickly swap between gears with the same wheel.
just something to consider before you over complicate your purchase.
Well, my current lowest gearing is 36/25, which gives me ~38 gear inches, and there are a couple places around town where I have to stand on the pedals just to keep moving forward in that gearing. The places I normally ride to don't otherwise require any serious climbing, except for the overpasses over the interstates. (I cross one twice a week due to band practice) My current highest gearing is a 48/12, which gives me about 105 gear inches, and there are only a couple places I can head downhill and really spin in that gearing. Given all that, and a slightly wonky left knee, I either need more than one gear, or a very moderate gearing and careful route planning. (the overpass, however, is unavoidable unless I want to go many miles out of the way to go around it.)