The AMA Motocross Championship is the major motocross series of the United States, held since 1972. It is sanctioned by the American Motorcyclist Association and 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.[1] 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.[2]
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.[3] In 2006, the 250 cc division was renamed the MX Class, with an engine formula allowing for 150–250 cc two-stroke or 251–450 cc four-stroke machines.[4] 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.
Contents |
| Year | 500cc | 250cc | 125cc |
|---|---|---|---|
| 1972 | Brad Lackey (Kawasaki) | Gary Jones (Yamaha) | |
| 1973 | Pierre Karsmakers (Yamaha) | Gary Jones (Honda) | |
| 1974 | Jimmy Weinert (Kawasaki) | Gary Jones (Can-Am) | Marty Smith (Honda) |
| 1975 | Jimmy Weinert (Yamaha) | Tony DiStefano (Suzuki) | Marty Smith (Honda) |
| 1976 | Kent Howerton (Husqvarna) | Tony DiStefano (Suzuki) | Bob Hannah (Yamaha) |
| 1977 | Marty Smith (Honda) | Tony DiStefano (Suzuki) | Broc Glover (Yamaha) |
| 1978 | Rick Burgett (Yamaha) | Bob Hannah (Yamaha) | Broc Glover (Yamaha) |
| 1979 | Danny LaPorte (Suzuki) | Bob Hannah (Yamaha) | Broc Glover (Yamaha) |
| 1980 | Chuck Sun (Honda) | Kent Howerton (Suzuki) | Mark Barnett (Suzuki) |
| 1981 | Broc Glover (Yamaha) | Kent Howerton (Suzuki) | Mark Barnett (Suzuki) |
| 1982 | Darrell Schultz (Honda) | Donnie Hansen (Honda) | Mark Barnett (Suzuki) |
| 1983 | Broc Glover (Yamaha) | David Bailey (Honda) | Johnny O'Mara (Honda) |
| 1984 | David Bailey (Honda) | Rick Johnson (Yamaha) | Jeff Ward (Kawasaki) |
| 1985 | Broc Glover (Yamaha) | Jeff Ward (Kawasaki) | Ron Lechien (Honda) |
| 1986 | David Bailey (Honda) | Rick Johnson (Honda) | Micky Dymond (Honda) |
| 1987 | Rick Johnson (Honda) | Rick Johnson (Honda) | Micky Dymond (Honda) |
| 1988 | Rick Johnson (Honda) | Jeff Ward (Kawasaki) | George Holland (Honda) |
| 1989 | Jeff Ward (Kawasaki) | Jeff Stanton (Honda) | Mike Kiedrowski (Honda) |
| 1990 | Jeff Ward (Kawasaki) | Jeff Stanton (Honda) | Guy Cooper (Suzuki) |
| 1991 | Jean-Michel Bayle (Honda) | Jean-Michel Bayle (Honda) | Mike Kiedrowski (Kawasaki) |
| 1992 | Mike Kiedrowski (Kawasaki) | Jeff Stanton (Honda) | Jeff Emig (Yamaha) |
| 1993 | Mike LaRocco (Kawasaki) | Mike Kiedrowski (Kawasaki) | Doug Henry (Honda) |
| Year | 250cc | 125cc | Women's MX |
|---|---|---|---|
| 1994 | Mike LaRocco (Kawasaki) | Doug Henry (Honda) | |
| 1995 | Jeremy McGrath (Honda) | Steve Lamson (Honda) | |
| 1996 | Jeff Emig (Kawasaki) | Steve Lamson (Honda) | Shelly Kann |
| 1997 | Jeff Emig (Kawasaki) | Ricky Carmichael (Kawasaki) | Tracy Fleming |
| 1998 | Doug Henry (Yamaha) | Ricky Carmichael (Kawasaki) | Dee Wood |
| 1999 | Greg Albertyn (Suzuki) | Ricky Carmichael (Kawasaki) | Stefy Bau |
| 2000 | Ricky Carmichael (Kawasaki) | Travis Pastrana (Suzuki) | Jessica Patterson |
| 2001 | Ricky Carmichael (Kawasaki) | Mike Brown (Kawasaki) | Tania Satchwell |
| 2002 | Ricky Carmichael (Honda) | James Stewart Jr. (Kawasaki) | Stefy Bau |
| 2003 | Ricky Carmichael (Honda) | Grant Langston (KTM) | Steffi Laier |
| 2004 | Ricky Carmichael (Honda) | James Stewart Jr. (Kawasaki) | Jessica Patterson |
| 2005 | Ricky Carmichael (Suzuki) | Ivan Tedesco (Kawasaki) | Jessica Patterson |
| Year | MX Class | MX Lites Class | Women's MX |
| 2006 | Ricky Carmichael (Suzuki) | Ryan Villopoto (Kawasaki) | Jessica Patterson |
| 2007 | Grant Langston (Yamaha) | Ryan Villopoto (Kawasaki) | Jessica Patterson |
| 2008 | James Stewart Jr. (Kawasaki) | Ryan Villopoto (Kawasaki) | Ashley Fiolek |
| Year | 450 Class | 250 Class | Women's MX |
| 2009 | Chad Reed (Suzuki) | Ryan Dungey (Suzuki) | Ashley Fiolek |
| 2010 | Ryan Dungey (Suzuki) | Trey Canard (Honda) | Jessica Patterson |
| 2011 | Ryan Villopoto (Kawasaki) | Dean Wilson (Kawasaki) | Ashley Fiolek (Honda) |