I finally took the plunge and converted my 24-speed CX bike to a single-speed last night. Thumbshifters, front der, cassette, big ring, granny - gone. I kept the rear der to use as a chain tensioner/aligner, although I'm only using the upper pulley and can grind off the lower cage. I wimped out and got Spot's spacer kit and pirated the 14T off my old XT cassette. I used the existing chain, 'cause the new one I bought kept skipping. The new stem is an engraved Pinarello by 3TTT that I found in my basement. Questions:

1. How good does my chainline have to be?
2. I can't get the chainring bolts to hold the chainring tightly onto the crank. There's just a hint of play. Should I use a couple of thin washers?
3. How uncool is it to use a chopped rear der as a chain tensioner? It's Suntour from the 80's...

The new stem dropped my straight bar about 3" from its old position, so I am much more aerodynamic and teh f4st4r! I rode it today, and it feels lighter and less sketchy than before. I'll post some pictures soon.