Mountain biking
Mountain biking is a sport which consists of riding bicycles off-road, often over rough terrain, using specially adapted mountain bikes or hybrid/cross road bikes. Mountain bikes share similarities with other bikes, but incorporate features designed to enhance durability and performance in rough terrain.
Mountain biking is growing but can generally be broken down into multiple categories for example: XC cross country, DH downhill, FR freeride, AM All Mountain, Urban trials/street riding and DJ Dirt Jumping. Each has differing levels of safety-consciousness and varrying types of mountain bikes and riding gear. A combination sport named mountain bike orienteering adds the skill of map navigation to mountain biking. (source: wikipedia)