Out of all bikes, the most popular form of biking would be mountain biking. Mountain biking takes many forms, but the most popular subcategory is trail riding. Trail bikes can come in the form of a hardtail or full suspension bike and are do-it-all machines that are confident in almost any terrain. A trail bike usually has between 120 and 140mm of travel and their frames are most commonly aluminum alloy or carbon fiber. Trail bikes are versatile machines that can handle all types of terrains and can get away with riding all types of trails.