huh? that doesn't make sense...did you mean to say that it IS your favorite bike? Elaborate.

Also, folding bike, really? I have never ridden one but I can imagine that they wouldn't be nearly as good of a ride as a regular road bike. I wouldn't feel too bad about locking up a kilo/old road bike outside 24/7.

OP- your chainline will change when you do something w/ your crank. It might be hard to get a perfect chainline w/ your existing BB and crank. If you really want a good chainline, you should just get a new crankset and BB. You can get a cheap Pake one and Shimano UN54 BB for like $70. When I did a conversion, I got lucky w/ the crank. I used an old road triple with the chainring in the middle. I used a 107mm BB and it gave a near perfect chainline. 1/8" off chainline isn't TOO bad, but it might bother you. BUT, I would wait until you put your track wheelset on to see how the chainline is. Most track wheelsets necessitate a chainline of ~42mm