This has been a gray, wet, and cold autumn in the Midwest and Great Lakes, so riding days have been few. But the other day I managed to take my new fixed gear conversion out for a 20 mile ride on a paved MUP. I really enjoyed it! When I first became aware of fixed gears being used anywhere but the track I thought "why would anyone want to?" Now I see. Because the momentum of the bike actually assists your pedaling keeping a brisk speed and good cadence on the flat is, if anything, easier than on a freewheeled bike. You just sort of soft pedal along and hey presto, you're doing 18+mph without breaking a sweat.
I've yet to try it on hills, but on the mild grades of this MUP I either just put more oomph into the upstroke (I'm using Look clipless pedals), or on a bit steeper upgrade stand and mash. Once you have the hang of it it's pretty easy. And even on upgrades I think you have a bit of that momentum push helping you pedal; the same grades seemed easier than I remember on my road bike (I ride this path often). Getting started you can accelerate slowly in the seat without strain or stand and mash (and imagine yourself sprinting in the Tour).
This is all quite unexpected. Esepecially for a guy whose sole bike at the beginning of this season was a Trek hybrid. I really thought a fixie would be the bike equivalent of eating your spinach; something I'd have to make myself do for the sake of training and fitness instead of riding my geared bike for "fun". But they're both fun! You do not ride a fixie for raw speed (well, unless you're a track racer) but it is an enjoyable (unexpectedly so!) way to improve your pedaling technique and strength.
I really hope I get to try it out on a hilly course before winter clamps down.
The thrift shop 80s vintage Schwinn World Tour 4130 CroMo main tube frame might not be the lightest or have any "cachet" but it is a comfortable and fairly responsive ride. When I got the bike I overhauled the hubs, headset and BB and it's smooth and quiet.
But I have been coveteously visiting the IRO Website lately...
Give it a try! I think a fixed gear conversion would be an ideal winter project for you tinkerers and dump divers like Pastor Bob.
I'm probably going to sell the hybrid.