After looking at the many photos sent in by all who own a fixed or single speed bike, I now want to build one of my own. I have a Gary Fisher hybrid now with a front shock, gears: 21 spd, and very heavy. I know I can use most of the parts with a little improvision, but should I dump the frame and fork and buy a new one, replace the fork only, buy the frame with one with horizontal drops? I will have to spend $$ on a single ring crank and replace the cluster with a flip-flop or single on back, but what is the best option? I will use this as an all-around fun bike, beater, and when the weather is the nastiest in northern California; ya know, fenders, rack, mustache bars. Want to save my others: Cannondale Cyclocross and Trek 520 for nicer, non-destructive weather. Thanks for your insight.