Hey people, I'm just wondering why many pro riders and most amatuers as well have their seatpost cut off to a certain limit, have their seat lowered, and why some bikes only run on back brakes. I noticed that bikes made for dirt jumping and street only have front brakes, while skatepark/park bikes or freestyle have both brakes. What's the difference? Yes I did lower my seatpost and everything, and I find it really useful since my seat doesnt get in my way when I'm jumping onto a rail or manualing acros my driveway. I was just wondering if anyone knows....Thanks people!