Buy your first road bike used. My road bike that I do serious rides on offed me 1500 bucks. My first road bike cost me around 100 bucks and, and another 200 I sunk into the bike for tune ups, modifications and repairs. I still ride my first bike, I converted it to a fixed gear bicycle, useful for training since you can never coast on a fixed gear.
Talk to someone at your local independent bike shop. They usually don't carry used bikes, but most people who work there love bikes and will help you track down a good used bike. Since they are hoping you will remember them when you need to buy shit and do tune ups. Make sure you ask them about the proper size of the bike. This is crucial for mountain and road bikes. You want the bike prefect for your leg length and arm length.
Cycling is great cardio, a good portion of my training is dedicated to different levels of heart rates. You might want to rethink the gears you ride in if you aren't getting the range of aerobic and anaerobic exercise. Also fight some tougher climbs to ride.
I like to throw in some triathlon training with some rides on Saturdays. I ride to this lake near my place, lock up the bike, swim across a section, pop off and run to my bike. It's really fun, give it a try sometime.
Last edited by Cyclist; 07-30-2007 at 12:36 PM.