The reason I started to ride SS/fixed was many moons ago I was on my MTB and somehow my rear derailleur got sucked up into my wheel and pretty much crapped the bed. Luckily this happened at the tail end of the ride just before it started getting dark. A friend called me later that night and asked if I wanted to do an early morning ride the next day. Of course I said yes. But being young and having very limited funds and wanting to ride the next morning I picked a set of gears, shortened my chain and crossed my fingers.

That early morning ride was the best ride I'd had since I started biking. I climbed hills that I've never gotten all the way up before. I navigated the rocky trails like a bloodhound who has "cought the scent". Granted it wasn't a true fixed gear. I could still coast if I wanted to but I don't think that I did that much. Having the freedom of just looking at your surrounding concentrating on the course and not being concerned about what gear to be in and becoming "one" with the bike.

Eventually I bought a new derailleur form my bike, but that was long after I built myself a real FG bike.