I believe that fixed gear road bikes are the most efficient machine for transport. Yes, you have to get up and muscle up the hills and spin down them. But the incredable efficiency of a fixed drivetrain has to be expericenced to be believed. I often let friends try mine and most immediately comment on it. The effort to produce 20 mph on my fixed would only produce 18 mph on my geared ride. Even with hills, which I have here, the efficiency is still high. While climbing, your power output must be high with a fix, but you get up the hill much faster as well; so the total amount of work done more or less equals out.

I ride my fix commuting every day and on long Saturday rides, including centuries. I love the "flow" of the ride on the fix. I would say the only downside is the lack of freewheeling on the longer rides, to allow one to take a butt break from the saddle. On longer rides, I always like to see some hills later in the ride so that I can get up off my butt!

Dave