I read here with interest the different posts about mtn bike vs. road bike. I am into riding for the exercise. Not to go fast. I seem to get a better workout with the mtn bike. I can also go off road with it and it is more comfortable. A winner all around for me. I wouldn't beat anyone on a road bike so speed doesn't bother me. I need the exercise and to burn the calories and get more of both with the mtn bike. I burn more calories in 1 hour of riding the mtn bike then I do riding the road bike for the same time.