I'm continuing my search for a bike commuter. I'm looking for bikes near Amherst, MA in Western Mass Craigslist; anything $250 or below is feasible. So far, my finds include:

1. http://westernmass.craigslist.org/bik/3984070352.html

2. http://westernmass.craigslist.org/bik/4101140151.html

3. http://westernmass.craigslist.org/bik/4012380542.html

I like number 3 the best.

I'm going to go try out said bike in a few hours; if it fits, would it be possible to change the tires to ones capable of both paved road and dirt/slightly rocky paths? I'd also like to put some integrated shifters on it.