I plan to mostly us a backpack to carry gear and supplies. My commutes will be very short, since I go to school in a town of 12,000, only a few miles to where ever I would like to go. I just tried out the FASTBACK and enjoyed it quite a bit. It was the XL size since I am 6'5''. Plan on going for longer rides for fun and exercise. I will be weighing around 230 lbs in a few months; I'm less than that right now. Is this a sturdy enough bike for what I want? It is the 07 model and the LBS is asking $600 for it.