Hi, I'm new here. I am hopefully moving to Austin within the next few weeks, at least by June, and I want to get into cycling (I am currently still in College Station). Right now all I have is a mountain bike that I ride to work and back which takes me about 25 min. to get there and 25 to come home. It's just starting to feel really heavy I guess is the word because it's like 30 lbs. Though it's still fun to ride it! Anyway, I'm kind of interested in perhaps getting a road bike, however I'm not sure that I can afford a brand new one. My question is, what should I look for in a used bike to make sure that I'm getting something that is decent? I've never owned or used a road bike before. I also feel like I'm going to have a hard time finding one used because I'm fairly tall (5'10). My mountain bike is a 20inch, I'm assuming I'll need a 54 cm or so road bike? Thanks!