Whether you ride for sport or as a hobby, mountain biking fits into several different categories.  Each category has it own unique styles and requirements.  Below are 9 of the cateorgies for mountain biking:

1.  BMX
BMX biking is a style using bikes with 20 inch wheels. You will often find BMX bikes being used at skate parks or with dirt jumps.  It is easier to perform tricks and stunts with BMX bikes because of their smaller wheels and wheel bases.
and shorter wheel bases, BMX bikes are much easier
to perform tricks and stunts with.

2.  Cross country
Cross country biking is the least rigorous form of mountain biking.  This type of mountain biking involves riding your bike up and down hills.  While it is the least rigorous style of mountain biking, cross country bikers are generally very fit because of the long distances they ride up and down hills.

3.  Cyclo cross
This is a cross between road and mountain biking. In cyclo cross biking, bikers ride over obstacles, through rivers, and off course.

4.  Dirt jumping
Dirt jumping involves jumping the bike over large man-made dirt jumps and doing tricks while in the air.  These jumps are normally close together so riders can go over six or more jumps in one run, gaining momentum to give them more to create greater speed for bigger jumps.

5.  Downhill
In downhill mountain biking, riders race downhill as fast as possible.  This style of riding is very intense and offers riders the chance for ultimate thrills and excitement.

6.  Freeride
In free riding the bikers finds the perfect line down the mountain using all of the terrain to express themsleves.  These competitions are very popular, as riders choose their own styles of expression

7.  Single speed
No to be confused with fixed gears, single speed is a form of cross country biking that’s done using a bike with only one gear and fewer components.  The focus with single speed riding is simplicity.  The straight chain line will provide efficient pedaling, and the lack of components mean less mechanical problems and a lighter bike.

8.  Street and urban
Street and urban riding incorporates riding in urban areas, along ledges, and other types of man made obstacles. Riders of street and urban biking will do tricks such as stalls and grinds while riding.

9.  Trails
Trials are considered a form of mountain biking, although the bikes that are used look nothing like mountain bikes.  They use 20 or 26 inch wheels and sport small, low frames.  Trail riders will hop and jump their bikes over obstacles, which requires an extreme amount of balance and concentration.