probably not worth converting. Vertical dropouts means you'll need to find the magic gear ratio, as others pointed out, and your rear triangle is almost certainly not spaced 120mm (I'm guessing the bike is a 24 or 27 speed), which will make getting your chainline straight a pain in the ass. It could be done, but you would probably need to spend a bit of money to do it. If you really want a fixed on the cheap the best thing to do is to find an old 10 speed frame with vertical, I mean horizontal, dropouts, 120mm rear triangle and replace the rear wheel, bb, crankset, and chain.
Last edited by egbert; 09-10-06 at 07:15 PM.