A dirt bike is a special type of motorcycle that has been designed specifically for riding on unpaved ground. Dirt bikes are generally more lightweight than standard motorcycles. They're also outfitted with more rugged tires and better suspension so they can travel off-road and handle the ordeals of cross-country racing.

The sport of cross-country racing officially began in 1924. The first race was held in England and was supposed to determine which Englishmen were the better riders, those from the North or those from the South. The Auto Cycle Union required the organizers of the event to give it an official name and the term 'scramble' was chosen.

The race didn't determine who the better riders were, but it did give birth to a sport that would ultimately become an international success. The French modified scrambling by adding laps and jumps. The French also changed the name of the sport to motocross, which was a combination of the words motorcycle and cross-country.

The courses used in motocross racing evolved over time with several manmade obstacles being added, and eventually these manmade courses made their way indoors. The inside races were given the name supercross. Today supercross events are held in venues like football and baseball stadiums.

Not only did the racing courses evolve over time, so did the bikes. In 1973 Honda introduced its first two-stroke motorcycle, the Honda CR 250M, which quickly became a favorite with motocross racers. Just two years later, Yamaha revolutionized racing even further with the Yamaha YZ.