The AMA Motocross Championship is an American motorcycle racing series. The motocross race series was founded and sanctioned by the American Motorcyclist Association (AMA) in 1972. The series is the major outdoor motocross series in the United States and is managed by MX Sports Pro Racing.
The series began in 1972 with the introduction of two classes based on 500 cc and 250 cc engine formulas. A 125 cc class was added in 1974. As motocross technology developed, 500 cc two-stroke motocross bikes became too powerful for the average rider and, faced with diminishing numbers of competitors, the A.M.A. discontinued the 500 cc class after the 1993 season. A women's national championship series was introduced in 1996.
Facing tightening emissions regulations, in 1997, the A.M.A. increased the allowable displacement capacity for four-stroke engines, in an effort to encourage manufacturers to develop environmentally friendlier four-stroke machines. In 2006, the 250 cc division was renamed the MX Class, with an engine formula allowing for 150–250 cc two-stroke or 250–450 cc four-stroke machines. The 125 cc class was renamed the MX Lites Class, allowing 0–125 cc two-stroke or 150–250 cc four-stroke engines. In 2009, the MX class was renamed the 450 Class and the MX Lites class was renamed the 250 Class, to reflect the fact that all the competing manufacturers had adopted four-stroke machinery.
AMA Motocross Championship Wikipedia
Most Overall Wins
In the 1970's promoters such as Bill France started bringing motocross races in from the country to stadiums within cities. Instead of being built upon natural terrain, dirt was imported into the stadiums where promoters tried to emulate the motocross tracks. In 1972 Mike Goodwin and Terry Tiernan, the President of the AMA, put on one of these stadium races in the Los Angeles Coliseum. The race was dubbed as the Super Bowl of Motocross. Eventually this form of racing evolved into it's own sport and series with the name Supercross which was a shortening of the original "Super Bowl of Motocross." American Motocross racing distinguished itself from European Motocross by having 2 different season championships run each year for each class both sanctioned by the AMA. Currently the AMA runs their 17 round Supercross championship from the first weekend in January to the first weekend in May and then the 12 round outdoor Motocross championship from mid May through late August.
Whereas AMA Motocross is 2 30 minute plus 2 lap motos per each round with the winner being the rider with the highest combined points total for the 2 motos, in Supercross their is only one points paying race per round. Around 40 riders qualify for each Supercross round. Heat races and LCQ's are used to bring the field down to 22 riders for a points paying main event for each round. A main event is 20 minutes plus 1 lap for the 450 class and 15 minutes plus 1 lap for the 250 class. There is no 250 Supercross national champion like there is for motocross. The 250 class in Supercross is split into East and West divisional rounds with an All Star race combining the top riders of each division at the final round in Las Vegas.
See AMA Supercross Championship