I just bought a new trek 4300 and I really enjoy biking, however I can only get to trails on weekends. I realize I would have to work a lot harder than I would on a mtb than I would on a road bike if I was to ride on the street, but if I am really itching to ride, is there any damage that would be done to my trek if i were to ride say 15 miles on pavement? I am busy during the week and have no time to drive to trails (although I wish I did).