CZ Only Classes                                       CZ World Championship Classes

                                      Special Classes                                           Non CZ Classes


All classes will have a Novice, Intermediate and Expert designation, except the CZ World Championship Races;  

  • If there are not enough entries, Novices riders will line up behind the Intermediates and Experts and be turned lose roughly 30 seconds after first line of riders.
  • Any CZ racer may enter any class his/her bike(s) falls into depending on year and suspension travel
  • All 100’s will be included in the 125 class. All 175’s will race in the 250 class. Anything over 301cc will race with the 500’s 
  • Entries in the NorCal Vintage 100cc Challenge will be 100cc’s only 
  • Any racer may move up a class (ie: Class of 69 to Class of 74, Class of 78 to Class of 84) but not the reverse

The Don Matthews CZ World Championships is founded on the principles of honesty, generosity and good sportsmanship. We are ambassadors of our sport and emphasize cooperation with each other rather than arguing and therefore, there is no protest recourse for racers.


For questions or rules clarification, contact Jim Buckalew @ Facebook or email: gmkjimb@yahoo.com


CZ Only Classes

All CZ classes will have a Novice, Intermediate and Expert designation.


CZ Only Class of 70=7/4 travel   

  • Twinport and Sidepiper (Twinport/Sidepiper = all 250-360cc 7/4 suspension travel)   

Class of 74 = 7/4 travel   

  • CZ Only Class of 74  125cc 
  • CZ Only Class of 74  250cc 
  • CZ Only Class of 74  500cc 
  • CZ Only Class of 74  Women 
  • CZ Only Class of 74  Age+50 
  • CZ Only Class of 74  Age+60
  • CZ Only Class of 74  Age+70 

Class of 78= over 7/4 travel 

  • CZ Only Class of 78  125cc 
  • CZ Only Class of 78  250cc  
  • CZ Only Class of 78  500cc  
  • CZ Only Class of 78  Women  

CZ World Championship

All CZ World Championship classes  will have an  Intermediate and Expert designation only. (7/4 travel)  


  • CZ International Trans-Am 250cc Age  -50  
  • CZ International Trans-Am 250cc Age +50   
  • CZ International Trans-Am 500cc Age -50  
  • CZ International Trans-Am 500cc Age+50
  • CZ International Trans-Am Women's Expert    

Special Classes

  • LEGENDS 2 MOTOS  National level riders who raced prior to 1975, all engine sizes and bikes welcome. First race of the day


  •  ALL Hodakas in  one race-two motos  scored separately. 100cc, 125cc, 175cc 250cc. Nov/Int scored together and Exp by themselves. 1st moto follows CZ classes


  • CZ Northern vs Southern California Team Race.
    ONE MOTO, 7/4 travel, all engine sizes, 3 rider teams, lowest score wins. Perennial trophy. Race held at halftime.


  • NorCal Vintage Racing 100cc Challenge This includes any eligible (21” front and 18/19” rear wheels) 100cc motorcycle up to 1983. Drum brakes are highly encouraged (but not required), unlimited suspension travel, linkage, non-linkage mono shock and twin shock. This is an air cooled only class. Four strokes are welcome, but only air cooled, with a maximum over bore to 150cc’s with 21” front and 18/19 rear” wheels. Race held at halftime .

Non - CZ Classes

Non- CZ Classes

  • Class of 69 ​125cc   This is the Premier Motocross Class.  These bikes started life as street bikes but were converted to off-road use. Triumph, Norton, Royal Enfield, BSA and other twins and single 4-strokes and pre-1969 2-strokes. 1920-1969
  • Class of 69 250cc This is the Premier Motocross Class. These bikes started life as street bikes but were converted to off-road use. Triumph, Norton, Royal Enfield, BSA and other twins and single 4-strokes and pre-1969 2-strokes. 1920-1969
  • Class of 69 500cc This is the Premier Motocross Class. These bikes started life as street bikes but were converted to off-road use. Triumph, Norton, Royal Enfield, BSA and other twins and single 4-strokes and pre-1969 2-strokes. 1920-1969
  • Class of 74 125cc  125 powered air-cooled, reed valve or piston port; twin shocks with 7 inches of travel in the front and 4 inches of travel in the rear. These bikes are equipped with single leading drum brakes, front and rear. Any bike from 1970-1974, but this class also includes some newer machines like 1974.5 Maico 125’s GP’s, 1975 XL125 1975-76 KX125 
  • Class of 74 250cc  250 powered air-cooled, reed valve or piston port; twin shock with 7 inches of travel in the front and 4 inches of travel in the rear. These bikes are equipped with single leading drum brakes, front and rear. Any bike from 1970-1974, but this class also includes some newer machines like 1974.5 Maico 250 GP’s, 1975 XL250 and 1975-76 KX250.
  • Class of 74 500cc  500 powered air-cooled, reed valve or piston port; twin shock with 7 inches of travel in the front and 4 inches of travel in the rear. These bikes are equipped with single leading drum brakes, front and rear. Any bike from 1970-1974, but this class also includes some newer machines like 1974.5 Maico 400/440GP’s, 1975 XL350’s, and 1975-76 KX400’s.

Non- CZ Classes

  • Class of 78​   125cc  125cc air-cooled with up to 9 inches of suspension travel, front and rear. These bikes have leading axle front forks and drum brakes, front and rear; no dual leading shoe brakes. (Yamaha early mono shock is OK, but only up to 9” of travel) Any bike from 1975-1978 
  • Class of 78​  250  250cc air-cooled with up to 9 inches of suspension travel, front and rear. These bikes have leading axle front forks and stop with drum brakes, front and rear; no dual leading shoe brakes. (Yamaha early mono shock is OK, but only up to 9” of travel) 1978-1/2 C2 RM250)  Any bike from 1975-1978 
  • Class of 78​   500  500cc air-cooled with up to 9 inches of suspension travel, front and rear. These bikes have leading axle front forks and stop with drum brakes, front and rear; no dual leading shoe brakes. (Yamaha early mono shock is OK, but only up to 9” of suspension travel) 1975-80 TT500’s in stock condition 1978-1/2 RM400 are OK) Any bike from 1975-1978 


Non -CZ Classes

  • Class of 84 ​125  125cc air- or liquid-cooled with an unlimited amount of travel, front and rear. This includes linkage rear suspension and Single Disc Front Brake. Any bike from 1979-1984
  • Class of 84 ​250 250cc air- or liquid-cooled with an unlimited amount of travel, front and rear. This includes linkage rear suspension and Single Disc Front Brake. Any bike from 1979-1984
  • Class of 84 ​500 500cc air- or liquid-cooled with an unlimited amount of travel, front and rear. This includes linkage rear suspension and Single Disc Front Brake. Any bike from 1979-1984
  • Pre Modern 125 up to 1996  Air or liquid-cooled with an unlimited amount of travel, front and rear disc brakes. This class applies the “Like Design” rule, if later bikes are effectively the same. No Aluminum Frames.
  • Pre Modern 250 up to 1996  Air or liquid-cooled with an unlimited amount of travel, front and rear disc brakes. This class applies the “Like Design” rule, if later bikes are effectively the same (ATK air cooled or LCQ250’s). No Aluminum Frames. 
  • Pre Modern 500  up to 1996  Air or liquid-cooled with an unlimited amount of travel, front and rear disc brakes. This class applies the “Like Design” rule, if later bikes are effectively the same (ATK air cooled, XR600/XL650’s CR500’s / KX500’s until the end of production and Service Honda’s/Kawasaki’s CR500AF or KX500AF). No Aluminum Frames 


All Adult Mini Classes

You will need to choose one of the classes as they will run simultaneously.


  • Adult Mini Air Cooled  100cc-150cc  Air Cooled Stock Chassis and suspension. XRs, CRFs, TTRs, KLXs, DRZs Air cooled 4-stroke only 2 Valve heads (No 2-strokes)
  • Open Adult Mini   CRF150Fs Any Chassis / Suspension / Engine or Carb changes. Up to 100cc 2-strokes and liquid cooled 4-strokes (ie: CRF150Rs) This class also includes 4 stroke 2 valved engines with 21” front and 18” rear wheels. XR125/200’s (XR200’s up to 1984) and CRF230’s DR125/200’s XT125/200’s.