Thanks for the info. I ride the only bike I have, a Trek 4300 with knobby tires, to work and back. I am wondering how much easier it would be on a road bike with skinny tires. I have never ridden one before as I primarily enjoyed offroad stuff in the past.

Sub 7 mile trips up and down Atlanta hills on the mountain bike can be a bit of a workout. Plus my right knee has started to give me trouble. Do you long distance commuters think a road bike would be worth the purchase? If so, could you throw out suggestions? I don't plan on doing 80 mile rides on the weekend; just 13ish miles a day back and forth from work.

Thanks.