Alright..I joined this forum because of this thread. My fixed gear road bike has been my favorite since I built it several years ago. It's always the bike I consider first before a ride. For some reason, I like it better than my geared bikes when I'm out of shape and getting back on the saddle...and I love it even more when my legs are back and I can get the tires singing.
It's just a beat up old C-dale frame with some discarded components, and cheapo schrader-valve rims.
So..on to my latest bike. I originally built this up as a single speed, but after looking at the name "Fixation" for a few years, I decided to spin off the freewheel and spin on a cheapo track cog (with a healthy dose of red loctite). Wow, is this bike fun now. I can actually do hipster skids (in the dirt) without blowing out my knees and crashing. The only downside is the occasional pedal strike going over rocks. Oh well, pedals are replaceable.