1. BMX is a style where the bikes offer 20 inch wheels. These bikes are commonly used at skate parks or with dirt jumps.  Because of their smaller wheels and shorter wheel bases, BMX bikes are much easier to perform tricks and stunts with. 2.  Cross country This type of mountain biking involves riding your bike up and down hills.  Although it’s the least extreme form of mountain biking, most cross country riders are very fit and go on long [...]