Offroad cycling

Offroad cycling is a sport where bicycles (and unicycles!) are ridden outside of standard grounds, for example on narrow mountain trails.

For as long as there have been bicycles, people have been riding and racing them off-road. However, factory-produced off-road bicycles have been around only since 1981.

Most commonly known by the name "mountain bike", these bicycles differ from road bicycles in several ways. Mountain bikes have a smaller and stronger frame, knobby tires on wheels that are wider and smaller in diameter, a lower range of gears to facilitate climbing up hills and over obstacles, a wider flat handlebar that allows a more upright riding position, and usually some form of suspension system for either the front wheel or both wheels. The inherent comfort and flexibility of the modern mountain bike has led to an estimated 80% market share in countries like the United States, United Kingdom, Canada, Australia, and New Zealand.

While it is estimated that only 10-20% of mountain bikes are actually ridden off-road, the sport of mountain biking has seen an explosion in popularity and diversification.

Sub-categories of Mountain biking include:

Cross-country racing- Mass-start races over varied terrain for distances around 30 miles. Professional level races are longer in distance.
Downhilling - Gravity assisted racing on specialized mountain bikes with long travel suspension and powerful brakes. Many ski areas are converted into biking venues in the summer. Bikers ride trams or chair lifts to the starting point at the top of the mountains.
Epic Riding - All day or multiday adventures in remote wilderness areas.
Dual Slalom - Head to head racing along man-made courses.
Trials - Slow negotiation of obstacles (man-made and natural).
Urban Scuttling - Jump/trick riding through urban areas.
Night Riding - Using battery powered headlights to ride off-road during nighttime.

External Links:

http://www.vorb.org.nz
http://www.mtbr.com - reviews of equipment and chat boards