The title says it all. I've always retrofitted old bikes as commuters. I figure if it can take fattish tires and a fender, the bike will work fine as a commuter. My all time favorite was a Peugeot UO-8 that had a lot of great old European parts and 700 by 38c tires; loved the bike but it got ripped off to feed some drug users habit.

I like steel because I like steel and it also makes it easier to mount a generator light. So I'm deciding which bike out of my collection to turn into a commuter. I had been using my Trek 720 set up as a 1 speed but the frame is no longer very straight (never crashed the bike but it has seen a lot of miles and it does not track as well as it used to) and it can't take larger than a 700 by 28 c with fenders. I'll eventually straighten out the frame but I figure it's time to move to something that can take fatter tires. I'm deciding between a rigid mountain bike (an old stumpjumper comp that I picked up on a craigslist find) or a bridgestone xo-2 frame that I have lying around. I'm leaning towards the mountain bike because it's pretty bomb proof but I figure it has short chain stays that will make using panniers a pain. The XO-2 is more of a road bike and will do better with a rack and panniers. Both are in good shape but don't look so great that I would hesitate to lock them up.

So if you were fixing up a new old bike, what would you absolutely do and what would you absolutely avoid? If you have pics of any great (or even not so great, ) new old commuters that you've built up, I'd love to see them. I'm just trying to get some ideas on how best to build up my commuter. Thanks!