I am presently riding a hybrid bicycle. It is far too heavy and slow. 49 year old man. Good shape. I would really like to begin riding. My hours are good for low traffic rides as I am up daily at 4:30 am. I am thinking I need a road bike, but I have not earned the right to get something that is a top quality bike. If I could be a 30 mile per week guy for a few months I would be happy. What kind of bike should I get? Please help!!