Also called a "dirt-jumper," a type of BMX or mountain bike built tough for jumping and stunt riding.
Cool It! - When temperatures soar, insulated bottles and hydration systems keep drinks cooler. And drinking cool liquid helps keep your body temperature lower. You can also freeze water in your bottles the night before the ride. But, fill only half way so you can top off with drink before the ride. The ice in the bottom will chill the liquid for a while. You can stuff ice in your hydration reservoir, too, to cool drinks and your back!