Many riders carry a backpack, including water, food, tools for trailside repairs, and a first aid kit in case of injury.

By 1979 he had developed a custom-built lightweight bicycle which was uniquely suited to the wet and muddy off-road conditions found in the south-east of England.

[9] There were several groups of riders in different areas of the U.S.A. who can make valid claims to playing a part in the birth of the sport.

Riders in Marin County, California and Crested Butte, Colorado, tinkered with bikes and adapted them to the rigors of off-road riding.

These early bikes were eventually modified with multi-speed gearing, drum or rim brakes, and motocross or BMX-style handlebars, creating "klunkers".

The first person known to fit multiple speeds and drum brakes to a klunker is Russ Mahon of Cupertino, California, who used the resulting bike in cyclo-cross racing.

By the mid-first decade of the 21st century, even some department stores began selling inexpensive mountain bikes with full-suspension and disc brakes.

A commonly cited reason for making the change to a rigid fork is the enhancement of the rider's ability to transmit force to the ground, which is important for performing tricks.

Often, they are similar to or in the same complex as a ski resort or they retrofit the concrete steps and platforms of an abandoned factory as an obstacle course, as with Ray's MTB Indoor Park.

[17][18][19] The level of protection worn by individual riders varies greatly and is affected by speed, trail conditions, the weather, and numerous other factors, including personal choice.

Because mountain biking takes place outdoors, ultraviolet radiation from sunlight is present, and UV rays are known to degrade plastic components.

Cross country mountain biking focuses on physical strength and endurance more than the other forms, which require greater technical skill.

Freeride / Big Hit / Hucking, as the name suggests, is a 'do anything' discipline that encompasses everything from downhill racing without the clock to jumping, riding 'North Shore' style (elevated trails made of interconnecting bridges and logs), and generally riding trails and/or stunts that require more skill and aggressive techniques than XC.

"Slopestyle" type riding is an increasingly popular genre that combines big-air, stunt-ridden freeride with BMX style tricks.

Slopestyle courses are usually constructed at already established mountain bike parks and include jumps, large drops, quarter-pipes, and other wooden obstacles.

Dirt jumping can be done on almost any bicycle, but the bikes chosen are generally smaller and more maneuverable hardtails so that tricks such as backflips, whips, and tabletops, are easier to complete.

Bikes are typically built from sturdier materials such as steel to handle repeated heavy impacts of crashes and bails.

The emphasis is placed on techniques of effectively overcoming the obstacles, although street-trials (as opposed to competition-oriented trials) is much like Street and DJ, where doing tricks with style is the essence.

Trail difficulty typically varies from gentle 'family' trails (green) through routes with increasingly technical features (blue and red) to those requiring high levels of fitness and skill (black) incorporating demanding ascents with steep technical descents comparable to less extreme downhill routes.

[35] Mountain biking is proven to improve mental health and well-being relating to coping abilities and reducing stress.

[37][38] Another risk factor is that mountain biking often takes place in wilderness or remote areas so emergency response can be delayed in the event of sustained injury.

Jumps and impacts can crack the frame or damage components or the tire rims, and steep, fast descents can quickly wear out brake pads.

The IMBA is a non-profit advocacy group whose mission is to create, enhance and preserve trail opportunities for mountain bikers worldwide.

[39] Mountain biking can result in both soil and vegetation damage, which can be caused by skidding, but also by the construction of unauthorised features such as jumps and bridges, and trails themselves.

[40] Several studies have reported that a mountain bike's impact on a given length of trail surface is comparable to that of a hiker, and substantially less than that of an equestrian or motorized off-road vehicle.

Mountain bikes are not bound to any specific type of infrastructure and can therefore move freely between ecological environments acting as a connecting dispersal vector between habitats.

[47] In an effort to understand and assess the socio-ecological consequences of mountain bikes as a vector for seed dispersal Fabio Weiss, Tyler J. Brummer, and Gesine Pufal conducted an environmental impact study on forest trails in Freiburg, Germany.

To mitigate the accidental dispersal of an unwanted invasive species, the authors of the study proposed the following measures to support conservation:[47] a) Clean the bike between rides in different habitats, before traveling and especially before entering sensitive natural areas and regions.

c) Educate mountain bike riders about the potential dispersal of different species (good stewardship begets riding privileges).

d) Encourage cooperation between mountain bikers and managing authorities (avoid condescending regulations, establishment of monitored designated riding areas).