• Velocette wins its only dirt track National (George Matheson at Hohukus half mile event)

• Introduction of “Class C” (production-based) racing, replacing the former “Class A” (purpose-built racing engines/chassis).
  
  
• Three professional divisions: Novice, Amateur, Expert.
  
  
• All divisions use 500cc overhead valve or 750cc pocket-valve engines on all tracks. Minor modifications are allowed; fuel is limited to pump gas only. Overhead valve engines will be subjected to this displacement disadvantage until 1970.
  
  
• All divisions use black numbers with district letters on white number plates. The district letter (designating the rider’s home state), is located in the lower right-hand corner of the number plate.
  
  
• No National Champion is recognized until 1935.

• Junior TT: 350cc (21.35ci) overhead-valve or 500cc (30.50ci) side-valve engines
  
  
• Senior TT: 500cc (30.50ci) overhead valve or 750cc (45.70ci) side-valve engines
  
  
• Unlimited TT: 0-1310cc (0-80ci) engines.

• JAP wins its first dirt track National (Andrew Hader at Syracuse, NY mile event)

• AMA crowns its first “Class C National Champion” in Woodsie Castonguay, winner of the “championship” event held on the mile oval at Langhorne, Pennsylvania.

• The AMA moves the “Class C National Championship” event to the mile oval at the Illinois State fairgrounds in Springfield, Illinois, where it stays until 1954, when the Grand National Championship is created.

• AMA permits the winner of the previous year’s Class C National Championship to wear the #1 plate for the first time.

• Norton wins its first dirt track National (Robert Sparks at Langhorne, PA mile event).

• All divisions limited to 500cc overhead valve engines or 750cc side-valve engines (replacing 750cc pocket-valve engines). Overhead valve engines will be subjected to this 250cc displacement disadvantage until 1970.

New TT Rules:
• Junior TT: 350cc (21.35ci) overhead-valve or 500cc (30.50ci) side-valve engines
• Senior TT: 500cc (30.50ci) overhead valve or 750cc (45.70ci) side-valve engines
• Unlimited TT: 1000cc-1310cc (61ci-80ci) engines.

• AMA issues "National Numbers" for the first time to the top riders in the nation. Numbers 1-14, 16-17, 21-27, 29, 32-33, 35, 38, 55, and 72 are issued.

• No racing due to WWII

• No racing due to WWII

• No racing due to WWII

• No racing due to WWII

• Harley-Davidson introduces the WR750

• JAP wins its last dirt track National (Cordy Milne at Los Angeles, CA short track event).

• Novice and Amateur division riders begin using yellow number plates with black numbers and district letters (previously had used white number plates with black numbers and district letters since 1933).

• Triumph wins its first dirt track National (Jimmy Phillips at Peoria, IL TT event).

• Harley-Davidson introduces the KR750
  
  
• BSA wins its first dirt track National (Al Gunter at Shreveport, LA half mile event).

• Indian wins its last dirt track National (Ernie Beckman at Williams Grove, PA half mile event).
  
  
• Indian Motorcycle Company goes out of business

• Novice division riders begin using green number plates with white numbers and district letters (previously had used yellow number plates with black numbers and district letters since 1948).

• AMA creates the Grand National Championship to award the National Championship to the rider who earns the most points at a series of events involving five disciplines: short track, half mile, mile, "TT", and road courses.
  
  
• Joe Leonard establishes new records for most consecutive GNC wins (4) and most wins in a season (8).

• Rookie Expert Brad Andres wins the first GNC event he enters - the Daytona 200.



• Brad Andres sets the record for wins during a rookie season with 5. This record is unbroken through 2008.



• Rookie Brad Andres wins the Grand National Championship.

• Class C 45 (TT): 500cc (30.50ci) overhead valve or 750cc (45.70ci) side-valve engines
• Class C 80 (TT): 1213cc (74ci) overhead valve or 1310cc (80ci) side-valve engines.

• AMA eliminates the Novice, Amateur, and Expert divisions in favor of Class B and Class A divisions.
• Novices and Amateurs are combined into the new Class B division, using yellow number plates with black numbers and district letters.
• Experts are redesignated as Class A riders, using white number plates with black numbers and district letters.
• For continuity, the AMA continues using the Amateur and Expert designations at Grand National Championship events.

• AMA eliminates the Class A and Class B designations and returns to the Novice, Amateur and Expert divisions as they existed in 1955.
• AMA introduces Probationary Novice as a subdivision within the Novice division.
• Probationary Novices (i.e. first-year Novices) use red number plates with white numbers and district letters.
• Novices continue to use green number plates with white numbers and district letters.
• In the interests of safety, Santa Fe Speedway (Hinsdale IL) puts all riders on 250cc machines for their short track events (previously all competitors had raced 500cc overhead valve or 750c side-valve engines on the short tracks). The move is supported by Harley-Davidson, even though they do not have a competitive bike. Most riders compete on BSA, Triumph, and NSUs.

• Joe Leonard wins his last career GNC event, and retires with the record for most career wins (23).



• Carroll Resweber ties Joe Leonard's record of winning four consecutive GNC events (set in 1954).



• Carroll Resweber wins an unprecedented fourth Grand National Championship.



• Santa Fe Speedway (Hinsdale, IL) hosts the first AMA short track National. No GNC points would be awarded for Short Track Nationals until 1964, however.

• Following Santa Fe Speedway's lead (see 1959), all short track equipment is limited to 250cc displacement (previously had been 500cc overhead valve or 750cc side-valve since 1933
• Midway through the season, Ascot Park and AMA District 27 put all novices on 250cc machines for safety.

New TT Rules:
• Formula C 45 TT: 500cc (30.50ci) overhead valve or 750cc (45.70ci) side-valve engines
• Formula C 80 TT: 1213cc (74ci) overhead valve or 1310cc (80ci) side-valve engines.

• Dick Mann becomes the first privateer rider to win the Grand National Championship.



• Matchless wins its first dirt track National (Dick Mann at Gardena, CA TT event).

• All Novice division equipment limited to 250cc displacement (previously had been allowed 500cc overhead valve or 750cc side-valve on half miles).
• AMA begins testing the use of brakes on Novice bikes at Ascot Park.


New TT Rules:
• Class C 250 TT: 0-250cc engines.
• Class C Heavyweight TT: 251-900cc engines.

• AMA continues testing use of brakes on Novice bikes at Ascot Park.

• Yamaha scores its first Grand National win (Dick Mann at Nelson Ledges, OH road race event).



• Matchless scores it last Grand National win (Dick Mann in Carpentersville, IL road race event).

• Class C Lightweight TT: 0-250cc engines.
• Class C Heavyweight TT: 251-900cc engines.

• Bart Markel completes the career "Hit For The Cycle" by winning the Hinsdale, IL short track event.

• Triumph scores its last short track National win (Gary Nixon at Houston, TX)



• Bart Markel scores his 24th GNC win, taking over the record for most career wins from Joe Leonard.

• Bultaco scores its first dirt track National (Ronnie Rall at Houston, TX short track event).
  
  
• Ossa scores its first dirt track National win (Dick Mann at Hinsdale, IL short track event).

• AMA rulebook permits brakes for the first time, stating that "brakes may be used".

• Harley-Davidson introduces the "iron" XR750.
  
  
• Yamaha scores its first dirt track National (Chuck Palmgren at Nazareth, PA mile event).



• Honda scores its first Grand National event (Dick Mann at Daytona, FL road race event).



• BSA scores its last half mile National (Dave Aldana at Terre Haute, IN)



• Triumph scores its last road race National (Gary Nixon at Loudon, NH).



• Mert Lawwill completes the career "Hit For The Cycle" by winning the Houston, TX short track event.

• Junior & Expert equipment limited to maximum 750cc displacement of any configuration or valve arrangement (since 1933, overhead valve engines were limited to 500cc while side-valve engines could displace 750cc).
• Competition Committee notes from 1969 show that speed concerns led to an original proposal to limit all engine displacement to 350cc. This was eventually raised to 650cc, then finally to 750cc.

• Dick Mann wins his second Grand National Championship eight years after winning his first, a new record.


BSA scores its last road race National win (John Cooper at Ontario, CA)


• Yamaha scores its first half mile dirt track National (Jim Odom at Corona, CA).



• Bart Markel wins his last GNC event, setting the record for most career wins (28).

• Probationary Novice division is eliminated.
  
  
• All Novice division riders use white number plates with red numbers and district letters (previously Probationary Novices used this color scheme; full Novices used green number plates)
  
  
• National Number assignments are changed. All National Numbers are assigned based on the final 1970 Grand National Championship point standings.

• Dick Mann becomes the first to complete the career "Grand Slam" (winning at least one short track, one TT, one half mile, one mile, and one road race GNC event) by winning the Homewood, IL mile event.



• BSA scores its last mile National win (Dick Mann in Homewood, IL)



• Ossa scores its last dirt track National win (Mike Gerald at Hinsdale, IL short track event).



• Harley-Davidson introduces the "alloy" XR750.

• National Number assignments changed.
• National Number 1 reserved for the defending Grand National Champion
• National Numbers 2 through 9 reserved for former Grand National Champions
• National Numbers 10 through 99 assigned on an annual basis, with most riders choosing to keep the same number year after year.
  
  
• Amateur division renamed to "Junior" division. Junior division continues to use yellow (or orange) number plates with black numbers and district letter.
• Junior division no longer competes at every Grand National Championship event.
• Select Grand National Championship events begin running a "Junior Invitational" for Junior division riders.

• Eighteen different riders score GNC wins, breaking the previous record of 16 (set in 1972).



• A record of 1.50 events-to-winners-ratio (18 winners in 24 events) breaks the previous record (1.43 EPWR set in 1958).



• Triumph scores its last Mile dirt track National (Gene Romero at San Jose, CA).



• BSA goes out of business

• Novice division (all tracks) and Junior & Expert (short track) equipment changed to permit 360cc engines, except for multi-cylinder two-stroke engines, which are limited to 250cc (previously had been 250cc displacement since 1961).
• Junior & Expert TT equipment limited to 750cc maximum.

• Kenny Roberts is the second rider to complete the career "Grand Slam" by winning the Peoria, IL TT event.



• Triumph goes out of business
  
  
• Triumph wins its last half mile dirt track National (Mike Kidd in Columbus, OH)
  
  
• Honda wins its first dirt track National (Mike Gerald at Houston, TX short track event)

• AMA revamps the Pro Numbering system.
  • District letter assignments are reconfigured. For example:
  • Wisconsin changes from "G" to "K"
  • Michigan changes from "E" to "X"
  • Oklahoma changes from "M" to "G"
  • California loses "X", gains "E", and retains "R", "Y", and "Z".
  • Illinois loses "S", but retains "P"
  • Most Novices change to triple-digit numbers followed by their new district letter. Few Novices hold two-digit numbers lower than 70.
    
    
  • Juniors and Experts continue to use single-digit and two-digit numbers followed by their new district letter.

• Kenny Roberts scores the first-ever "Grand Slam" in a single calendar year
  
  
• Kenny Robert wins the Indy Mile on the four-cylinder two-stroke TZ700, the only-four-cylinder DT win in history.

• Bultaco wins its last dirt track National (Terry Poovey at Talladega, AL short track event)



• Yamaha scores its last half mile dirt track National (Kenny Roberts at Terre Haute, IN).



• Goodyear introduces the DT-II tire specially designed for dirt track use.

• Junior & Expert divisions (non-short tracks) limited to maximum two cylinder engines.

• Jay Springsteen completes the career "Hit For The Cycle" by winning the Hinsdale, IL TT event.

• Novice division (all tracks) and Junior & Expert (short track) equipment limited to 250cc single-cylinder two-stroke engines (previously had been 360cc engines or 250cc two-stroke multi-cylinder engines since 1973).
• AMA Pro Rulebook requires the use of brakes for the first time, stating that "brakes must be used".

• Hank Scott records the first qualifying lap over 100mph (DuQuoin, IL, 7/30/1978)
  
  
• BSA scores its last TT National win (Alex Jorgensen in Gardena, CA)
  
  
• Norton scores its last dirt track National (Alex Jorgensen in Gardena, CA half mile event)

• Steve Eklund becomes the first privateer racer since Dick mann (1963) to win the Grand National Championship.



• Steve Eklund completes the career "Hit For The Cycle" by winning the San Jose, CA mile event.



• Rick Hocking completes the career "Hit For The Cycle" by winning the Hinsdale, IL short track event.



• Honda builds the first NS750
  
  



• Triumph wins its 68th and last dirt track National (Brad Hurst at Castle Rock, WA TT event).

• Junior division twin-cylinder engines must use 28mm intake restrictors (had been unrestricted previously).

• Kenny Roberts wins his 29th GNC event, taking over the record for most career wins from Bart Markel.



• Ricky Graham scores the first GNC dirt track win at an average speed over 100mph (Indianapolis, IN mile event 8/24/80).

• Junior division twin-cylinder engines must use 27mm intake restrictors (had been 28mm since 1979).

• Yamaha introduces the XV750 "Virago"-based flat tracker.
• 
  
  
• Can-Am wins its first dirt track National (Alex Jorgensen at Hinsdale, IL short track event).



• Alex Jorgensen completes the career "Hit For The Cycle" by winning the Hinsdale, IL short track event.



• The Yamaha XS650/750 wins its 23rd and final GNC event (Scott Pearson at Peoria, IL TT event).

• AMA introduces the "Battle Of The Brands", an additional competition class at AMA pro racing events for Novice and Junior competitors on 500cc single-cylinder engines.

• Jay Springsteen win his 30th GNC event, taking the record for most career wins from Kenny Roberts (29).



• The Rotax four-stroke single cylinder engine which will eventually record 52 GNC wins under various names (ATK, Can-Am, Rotax, Wood-Rotax, and Harley-Davidson) scores its first GNC win (Alex Jorgensen at Gardena, CA TT event)

• A record 35 events comprise the Grand National Championship calendar



• Honda introduces the RS750



• Yamaha ceases its factory effort



• Can-Am scores its final National win (Alex Jorgensen at San Jose, CA short track event).

• Randy Goss completes the career "Hit For The Cycle" by winning the St. Louis, MO short track event.

• Novice division (all events) and Junior & Expert (short track) equipment changed to allow 500cc four-stroke single cylinder engines (previously had been 250cc two-stroke single cylinder equipment since 1977).



• AMA eliminates the "Battle Of The Brands" division (in existence since 1981) due to the change to 500cc.



• AMA changes the number plate layout to locate the district letter in the lower left-hand corner of the number plate (letter had been in the lower right-hand corner since 1933).



• All Grand National Championship events include a Junior National Championship division for Junior division riders.

• Jay Springsteen wins his unprecedented 40th GNC event



• Scott Parker completes the career "Hit For The Cycle" by winning the Houston, TX TT event.

• Novice division changes to red number plates with white numbers and district letters (had used white number plates with red numbers and district letter since 1971).



• AMA changes the number plate layout to return the district letter to the lower right hand corner (where is had been from 1933 until 1983).



• AMA introduces the Pro-Am sanction, which enables riders to accumulate advancement points towards Junior and Expert while competing in amateur events.

• Bubba Shobert completes the career "Grand Slam" by winning the Phoenix, AZ half mile event.



• Doug Chandler completes the career "Hit For The Cycle" by winning the Gardena, CA half mile event.



• Bubba Shobert sets a new record for GNC wins in a season with 9 (besting Joe Leonard's 1954 record of 8)

• Grand National Championship loses a "leg" as Road Racing splits off into its own National Championship following the 1986 season. The Grand National Championship continues to feature short track, TT, half mile, and mile events.



• Novice division eliminated after the 1985 season.



• Pro-Am division introduced to replace the Novice division, allowing riders to maintain amateur standing in their home districts.



• Pro-Am division used red number plates with white numbers, but instead of the traditional district letter, riders use the first letter of their last name instead.



• Junior division twin-cylinder engines must use 28.5mm restrictors (up from 27mm since 1980).

• Expert division twin-cylinder engines at all Pro Racing events must use 33mm restrictors (previously unrestricted).



• Junior division twin-cylinder engines must use 29mm restrictors (up from 28.5mm since 1986).



• Junior & Expert division equipment rules concerning single-cylinder engine displacement changed to allow up to 600cc displacement (previously had been limited 500cc since 1984).
• Pro-Am division remains at 500cc four-stroke single-cylinder displacement limit.



• Pro-Am division begins using white number plates with red numbers and the first letter of the rider's last name (had used red plates with white numbers since 1985).

• AMA introduces the 600cc National Series for Junior & Expert competitors on 600cc four-stroke single-cylinder engines.



• Pro-Am equipment changed to 600cc four-stroke single-cylinder engines (previously was 500cc four-stroke single-cylinder engines; Junior/Expert single-cylinder equipment had been 600cc since 1987).

• Honda ceases its factory effort after the 1988 season

• Grand National Championship half mile and mile events are limited to 750cc twin-cylinder four-stroke engines.
  
  

• Scott Parker wins his fourth Grand National Championship, tying Carroll Reswebers's record set in 1961.



• Scott Parker wins his 41st GNC event, taking the career win total lead away from Jay Springsteen.

• Scott Parker wins his unprecedented 50th career GNC event.



• Chris Carr completes the career "Hit For The Cycle" by winning the Daytona Beach, FL short track event.

• Expert riders who have not scored Grand National Championship points the previous year are permitted to return to the Junior division.



• Pro-Am riders stop using the first letter of their last name on their number plates (as they had done since 1986) and return to the common practice of using their district letter.

• Ricky Graham wins his third Grand National Championship, nine years after winning his second. breaking for former record of eight years between titles set by Dick Mann in 1971.



• Ricky Graham wins six consecutive GNC events, smashing the record of four originally set by Joe Leonard in 1954, tied by Carroll Resweber in 1961, and tied by Scott Parker in 1989.



• Ricky Graham sets a new record for GNC wins in a season with 12 (besting Scott Parker's 1989 record of 10).

• Junior division is eliminated after the 1992 season.



• Expert division is renamed "Grand National Expert".



• Basic Expert division is introduced to replace the eliminated Junior division. Basic Experts are not permitted to compete at Grand National Championship half mile or mile events without special permission.



• Basic Experts use white number plates with black numbers and district letters, just like their Grand National Expert counterparts.



• Harley-Davidson 883 Sportster division is introduced, featuring essentially stock 883cc DOT-legal Sportsters with minimal modifications.

• Scott Parker wins an unprecedented fifth Grand National Championship.



• Scott Parker wins his unprecedented 60th career GNC event.

• Scott Parker wins an unprecedented sixth Grand National Championship.



• Scott Parker wins his unprecedented 70th career GNC event.

• Scott Parker wins an unprecedented seventh Grand National Championship.



• ATK wins its first dirt track national (Will Davis at Daytona Beach short track event).

• Scott Parker wins an unprecedented eighth Grand National Championship.



• Scott Parker wins his unprecedented 80th career GNC event.

• AMA introduces the Hot Shoe National Series as a "feeder" series to the Grand National Championship series.
  
  
• 600cc National Series eliminated after the 1996 season.
  
  
• Pro Regional Series eliminated after the 1996 season.
  
  
• Pro-Am division is renamed Pro-Sport.
  
  
• District letter assignments are reconfigured, in some cases introducing a different letter for Pro-Sport riders than Expert riders form the same district. Previously all pro riders from a district shared the same district letter. Some examples include Wisconsin, Michigan, and Washington, where Pro-Sport riders begin using L, J, and M, respectively, while their Expert counterparts continue using K, X, and W.
  
  

• Scott Parker wins an unprecedented ninth Grand National Championship and equally unprecedented fifth consecutive Grand National Championship.



• Scott Parker wins his unprecedented 90th career GNC event.



• The Honda RS750 scores its 79th and final GNC win (Rich King, Joliet, IL half mile event.

• AMA introduces the Supertracker division for Grand National Experts, open to all DOT-approved four-stroke twin-cylinder engines displacing up to 1000cc (water-cooled) or 1250cc (air-cooled pushrod).
  
  
• Supertracker division use black number plates with white numbers and district letters.
  
  
• Harley-Davidson 883 Sportster division begin using yellow number plates with black numbers and district letters.
  
  

• Scott Parker wins his last GNC event, setting the record for career GNC wins with 94.



• ATK wins its last dirt track national (Will Davis at Daytona Beach short track event).

• Short track events are now defined as courses less than 1,800 feet in length when measured 18" from the pole (previously had been 2,250 feet).
  
  

• Single-cylinder equipment in all divisions for short track and TT use limited to 505cc four-stroke engines (had een 600cc since 1987).
  
  
• Expert division twin-cylinder equipment expanded to include the previous Supertracker division: up to 1000cc DOT-approved twins-cylinder four-stroke engines (with water-cooling) or up to 1250cc DOT-approved twin-cylinder four-stroke engines (air-cooled push-rod engines).
  
  

• KTM wins its first dirt track National (Chris Carr at San Francisco, CA short track event).



• The Rotax four-stroke single cylinder engine which recorded wins under various names (ATK, Can-Am, Rotax, Wood-Rotax, and Harley-Davidson) scores its 52nd and final GNC win (Chris Carr at Oak Ridge, TN short track event).

• Chris Carr wins his fifth consecutive Grand National Championship (seventh overall), tying Scott Parker's record for consecutive titles set in 1998.

• Single-cylinder equipment in all divisions (Pro-Sport all; Basic Expert & Grand National Expert Short Track & TT) limited to 450cc four-stroke engines (had been 505cc since 2002).
  
  
• Grand National Championship is split into two separate series: Grand National Championship Singles (for short track and TT events) and Grand National Championship Twins (for half mile and mile events).
  
  
• Harley-Davidson 883 Sportster Division is eliminated after the 2005 season.
  
  
• Twin cylinder engines used at Grand National Half Mile events are unrestricted for the first time since 1987 (previously had been restricted to 33mm).
  
  
• Short track events are now defined as courses less than 1,750 feet in length when measured 18" from the pole (previously had been 1,800 feet).
  
  

• Basic Expert Twins division introduced for competition at Grand National half mile and mile events.
• Equipment will focus on 650cc twins, with purpose-built race engines (XR750 & RS750) restricted to 29mm
• Basic Expert Twins will use black number plates with white numbers and district letters.
• Basic Expert Singles will continue to use white number plates with black numbers and district letters.

• Kawasaki wins its first dirt track National (Henry Wiles at Peoria, IL TT event).

• Basic Expert Twins restrictor size lowered to 27mm (was 29mm) for purpose-built race engines (XR750 & RS750).



• Pro-Sport riders with sufficient single-cylinder experience are permitted to participate in the Basic Expert Twins division at Grand National Championship events

• Joe Kopp completes the career "Hit For The Cycle" by winning the Daytona, FL short track event.
• Jake Johnson completes the career "Hit For The Cycle" by winning the Springfield, IL mile event.

• Pro-Sport division renamed "Pro"
• Grand National Expert division renamed "Expert".
• Basic Expert Division eliminated. Basic Experts can choose whether to move into the new Pro or Expert divisions.
• Single cylinder equipment used at Grand National or Hot Shoe events must use OEM frames.
• Expert twin-cylinder engines are unrestricted for engines 750cc and less; restricted to 33mm for purpose-built race engines (XR750 & RS750), restricted to 38mm for other engines larger than 750cc.
• Pro division (singles only) participate at the Grand National Championship event.
• Pro division riders can compete in a Twin-cylinder class at Hot Shoe events

• Harley-Davidson XR750 and Honda RS750 engines to be restricted to 32mm.
• Twin-cylinder engines above 750cc to be restricted to 38mm.
• Single-cylinder engines must maintain the original valve size and valve angle as on the OEM product.
• The top 10 from the 2009 Pro Singles National Championship are granted provisional licenses to compete in the Grand National division at three events - Lake Odessa, MI, Castiloga, CA, and . Defending Pro Singles Champ Brad Baker makes the Grand National Main Event at Lake Odessa.

AMA PRO RACING
NUMBER PLATE DESIGNATIONS
1933-2009