Downhill biking (DH) will normally consist of using gravity to build up speed and the rider will be against the clock. 30 seconds intervals(seeded from slowest to fastest), on short courses are the norm. Riders are timed with equipment similar to that used in Downhill skiing, inluding large heavy duty pads and protective clothing. The placing is determined by the fastest times to complete the course; races are often won by margins of under a second. Downhill races are held on steep, downhill terrain with no climbing sections, resulting in high speed descents with many jumps and obstacles.

The 2009 Downhill World Champion is Steve Peat from UK. The 2009 Women's Downhill World Champion is Emeline Ragot of France.

Downhill Bikes are heavier than XC mountain bikes as they obviously use gravity to maintain speed. DH bikes are normally full suspension, lean back frame geometries, large diameter disc brakes included. Some compare downhill bikes to freeride bikes. However, freeride have steeper geometry and higher bottom bracket so that they are more suited to tricks and jumps, where as dowhill bikes are designed to be more stable around corners.

Downhill mountain bikers will be wearing body armour and full face helmets due to the risk involved in the fastest of all mountain biking hobbies!