MUD SESSION MAINTENANCE
Dirt Jumping is the practice of riding bikes over shaped mounds of dirt or soil and becoming airborne. The goal is that after riding over the 'take off' the rider will become airborne, and aim to land on the 'landing'. Dirt jumping can be done on almost any bicycle, but the bikes chosen are generally smaller and more maneuverable hardtails so that tricks e.g. backflips, are easier to complete. The bikes are simpler so that when a crash occurs there are fewer components to break or cause the rider injury. Bikes are typically built from sturdier materials such as steel to handle repeated heavy impacts of crashes and bails.
At the time, the bicycle industry was not impressed with the mountain bike, which many regarded as a short-term fad. In particular, large manufacturers such as Schwinn and Fuji failed to see the significance of an all-terrain bicycle and the coming boom in 'adventure sports'. Instead, the first mass-produced mountain bikes were pioneered by new companies such as MountainBikes (later, Fisher Mountain Bikes), Ritchey, and Specialized. Specialized was an American startup company that arranged for production of mountain bike frames from factories in Japan and Taiwan. First marketed in 1981, Specialized's mountain bike largely followed Tom Ritchey's frame geometry, but used TiG welding to join the frame tubes instead of fillet-brazing, a process better suited to mass production and which helped to reduce labor and manufacturing cost. The bikes were configured with 15 gears using derailleurs, a triple chainring, and a cogset with five sprockets.