DH

Downhill mountain biking (DH) is a genre of mountain biking practiced on steep, rough terrain that often features jumps, drops, rock gardens and other obstacles. Super Redbull video Downhill bikes are heavier and stronger than other mountain bikes and feature front and rear suspension with over 8 inches (20 cm) of travel, to glide quickly over rocks and tree roots. In competitive races, a continuous coursg the tape they must return to the course at the point of exit, unless they do not gain a time advantage from crossing the tape, in which case they can continue with their run.[citation needed] Riders start at intervals, often seeded from slowest to fastest, and courses typically take two to five minutes to complete with winning margins being often less than a second. Riders are timed with equipment similar to that used in downhill skiing.[1]

Racing history

The 1st downhill time-trial race took place in Fairfax, California on October 21, 1976 on a fireroad now referred to as Repack Road,[2][3][4] due to the need to repack the hub brake after each descent.[5] The bikes used were based on cruiser bicycles that had a drum or coaster brake that worked by pedalling backwards. The mechanism operated with a conical brake shoe being wound on a thread in a metal hub. To prevent the brake from seizing it was kept filled with grease. Heavy use during the descent would cause the brake to over heat, softening the grease and causing it to drain from the hub, requiring frequent repacking. Ten riders descended 1,300 feet (400 m) of Repack road in about 5 minutes.[6] The first bikes used for descending were known as "klunkers" olly[5] and Gary Fisher founded the company which named the sport, MountainBikes.[8] As mountain biking grew during the 80s, downhill riders continued to use either rigid or limited-travel (under 2 inches (5 cm)) suspension bicycles. Purpose-made downhill bikes started to appear in the 90s, with innovations such as dual crown forks and disc brakes, as well as more elaborate suspension designs. Later, riders from other disciplines began focusing on downhill, such as BMX racers Daniel Solano (Team Tomac Bikes), and Brian Lopes. Their influence is seen in the increased difficulty of many courses, with bigger jumps and drops added. The coming of age for downhill biking was its inclusion at the first UCI Mountain Bike Championship, held in 1990 in Durango, Colorado.