information:extraction
Protective gear

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. Protection becomes more important where these factors may be considered to increase the possibility or severity of a crash.

A helmet and gloves are usually regarded as sufficient for the majority of non-technical riding. Full-face helmets, goggles and armored suits or jackets are frequently used in downhill mountain biking, where the extra bulk and weight may help mitigate the risks of bigger and more frequent crashes.

Protective gear cannot provide immunity against injuries. For example, concussions can still occur despite the use of helmets, and spinal injuries can still occur with the use of spinal padding and neck braces. The use of high-tech protective gear can result in a revenge effect, whereupon some cyclists feel safe taking dangerous risks.

Because the key determinant of injury risk is kinetic energy, and because kinetic energy increases with the square of the speed, effectively each doubling of speed can quadruple the injury risk. Similarly, each tripling of speed can be expected to bring a nine-fold increase in risk, and each quadrupling of speed means that a sixteen-fold risk increase must be anticipated.

Higher speeds of travel also add danger due to reaction time. Because higher speeds mean that the rider travels further during their reaction time, this leaves less travel distance within which to react safely. This, in turn, further multiplies the risk of an injurious crash.

In general, although protective gear cannot always prevent the occurrence of injuries, the use of such equipment is appropriate, as is maintaining it in serviceable condition. Because mountain biking takes place outdoors, ultraviolet radiation from sunlight is present, and UV rays are known to degrade plastic components. Accordingly, and as a rule of thumb, a bicycle helmet should be replaced every five years, or sooner if it appears damaged. Additionally, if the helmet has been involved in an accident or has otherwise incurred impact-type damage, then it should be replaced promptly, even if it does not appear to be visibly damaged.