Adult Classes

Any manufacturer asking to have a bike homologated for the following year must submit an actual bike and spec to MMSX/Dirt Rider offices no later than December 31st.
It is the promoter's sole discretion to cancel or combine classes or re direct riders in other classes!

ALL CLASSES ARE "4-STROKES BIKES, AIR COOLED ONLY"

MM8 - TBParts.com Vintage Z50 vs. CRF50 88cc
8” Rear/ Front Wheel Amateur Class - No current AMA Pro license holders allowed. Must be 18 years of age or older as of race date. You must run an 8” Rear Wheel. All bikes must use Air-cooled, 4-stroke engines (maximum 88cc) with Open Cradle Frames.(no Aluminum frame), 2 shocks (or hard tail) on the frame 8” front wheels (maximum) are allowed. Manual Clutches are allowed. Maximum Wheel Base is 42 inches. Both wheels must be solid. NO regular spokes! Practice & qualifying - time TBD
Vintage Z50 88cc –one addition: No 4 valve heads
XR/CRF50 88cc – All must use Air-cooled, 4-stroke 88cc engines (no 49cc engines and no engines larger than 88cc) with Open Cradle Frames. 10” Rear wheel and 12” front wheels (maximum) are allowed. Manual Clutches are allowed. Engine Modifications are allowed except no 4 valve cylinder heads. Maximum Wheel Base is 45 inches.

MM10A –
10” Rear Wheel Amateur Class - No current AMA Pro license holders allowed. Must be 18 years of age or older as of race date. You must run a 10” Rear Wheel. All bikes must use Air-cooled, 4-stroke engines with Open Cradle Frames. 12” front wheels (maximum) are allowed. Manual Clutches are allowed. Engine Modifications are allowed. Maximum Wheel Base is 45 inches. Practice & qualifying - time TBD

MM10E- Premier Money Class
10” Rear Wheel Expert Class - Must be 18 years of age or older as of race date or possess an AMA Pro License. You must run a 10” Rear Wheel. All bikes must use Air-cooled, 4-stroke engines with Open Cradle Frames. 12” front wheels (maximum) are allowed. Manual Clutches are allowed. Engine Modifications are allowed. Maximum Wheel Base is 45 inches. Practice & qualifying - time TBD

MM12A-
12” Rear Wheel Amateur Class - No current AMA Pro license holders allowed. Must be 18 years of age or older as of race date. You must run a 12” Rear Wheel. All bikes must use Air-cooled, 4-stroke engines with Open Cradle Frames. 14” front wheels (maximum) are allowed. Manual Clutches are allowed. Engine Modifications are allowed. Maximum Wheel Base is 49 inches. Practice & qualifying - time TBD

MM12E-Premier Money Class
12” Rear Wheel Expert Class - Must be 18 years of age or older as of race date or possess an AMA Pro License. You must run a 12” Rear Wheel. All bikes must use Air-cooled, 4-stroke engines with Open Cradle Frames. 14” front wheels (maximum) are allowed. Manual Clutches are allowed. Engine Modifications are allowed. Maximum Wheel Base is 49 inches. Practice & qualifying - time TBD

MM35+
12” or 10” Rear Wheel Vet Class - You must be 35 years of age as of race date. You must run a 12 or 10” Rear Wheel. All bikes must use Air-cooled, 4-stroke engines with Open Cradle Frames. 14”/ 12” front wheels (maximum) are allowed. Manual Clutches are allowed. Engine Modifications are allowed. Maximum Wheel Base is 49 inches. For more details see MM10A/E or MM12A/E rules. Practice & qualifying - time TBD

MMW- Women's Class
Must be 14 years of age or older as of Race date. May race any bike that adheres to the MM10A/E and MM12A/E rules. Manual Clutches are allowed. Practice & qualifying - time TBD

MM10 Stock/Mod-
XR/CRF50, TT-R50, DRZ 70, Pitster XJR 90 SS and BRAAAP 88cc Motorcycles Only. – Must be 18 years of age or older as of race date. The following items must remain “Bone Stock”: Engine cases, Engine head and cylinder (No AFTERMARKET aluminum heads allowed, no cylinder spacers allowed), carburetor (re-jetting is allowed. Choke must remain on carb), carburetor manifold, engine appearance (do not paint or coat cases), frame, swingarm, forks, wheels hubs (10” only front and rear), brakes, fuel tank. (Stock cylinder can be bored/ ONLY stock cylinders allowed!)

Bikes can be modified by changing or adding the following parts: Upper triple clamps, handlebars, grips, brake cable, throttle cable, kill-switch, throttle assembly, sprockets, graphics, tires, piston, rings, exhaust system, clutch springs and plates (clutch must remain fully automatic, NO manual clutches allowed), dual action clutch allowed, however clutch lever must be removed, CDI box, air filter, fork springs, rear shock, chain, sprockets, foot pegs/mounts, skid plates, rims and spokes, shifter and brake lever, seat covers and foam, plastic (i.e.: fenders, shrouds, number plates can be replaced in color only- must have white backgrounds). Practice & qualifying - time TBD

MM12 Stock/Mod-
This Class is for KLX/DRZ110, CRF70, TT-R90 /110, Pitster MX110SS Motorcycles Only. – Must be 18 years of age or older as of race date. The following items must remain “Bone Stock”: Engine cases, Engine head and cylinder (No AFTERMARKET aluminum heads allowed, no cylinder spacers allowed), carburetor (re-jetting is allowed. Choke must remain on carb), carburetor manifold, engine appearance (do not paint or coat cases), frame, swingarm, forks, wheels hubs (10” only front and rear), brakes, fuel tank. (Stock cylinder can be bored/ ONLY stock cylinders allowed!)

Bikes can be modified by changing or adding the following parts: Upper triple clamps, handlebars, grips, brake cable, throttle cable, kill-switch, throttle assembly, sprockets, graphics, tires, piston, rings, exhaust system, clutch springs and plates (clutch must remain fully automatic, NO manual clutches allowed), dual action clutch allowed, however clutch lever must be removed, CDI box, air filter, fork springs, rear shock, chain, sprockets, foot pegs/mounts, skid plates, rims and spokes, shifter and brake lever, seat covers and foam, plastic (i.e.: fenders, shrouds, number plates can be replaced in color only- must have white backgrounds). Practice & qualifying - time TBD

MM16A Stock/Mod - PLAY BIKES CLASS! Plus ELECTRIC BIKES (QUANTYA AND ZERO ONLY, other brands will have to be approved by MMSX)
This Class is for KLX140/ DRZ125/ CRF100F/ XR 100/ CRF150F (air cooled), XTR 150 SC and TT-R125 Motorcycles Only (NO liquid cooled CRF150Rs allowed) Versions of bikes above with 14-inche rear wheels and 17-inch front wheels are acceptable in this class. All bikes are closed cradle frame and manual clutches! – Must be 18 years of age or older as of race date. The following items must remain “Bone Stock”: Engine cases, Engine head and cylinder (No AFTERMARKET aluminum heads allowed, no cylinder spacers allowed), carburetor (re-jetting is allowed. Choke must remain on carb), carburetor manifold, engine appearance (do not paint or coat cases), frame, swing arm, forks, wheels hubs (wheel size must remain stock), brakes, fuel tank. (Stock cylinder can be bored/ ONLY stock cylinders allowed!)

Bikes can be modified by changing or adding the following parts: Upper triple clamps, handlebars, grips, brake cable, throttle cable, kill-switch, throttle assembly, sprockets, graphics, tires, piston, rings, exhaust system, clutch springs and plates CDI box, air filter, fork springs, rear shock, chain, sprockets, mounts/mounts, skid plates, rims and spokes, shifter and brake lever, seat covers and foam, plastic (i.e.: fenders, shrouds, number plates can be replaced in color only- must have white backgrounds). Practice & qualifying - time TBD. Gas & Electric will be scored separately in main event.


WORLD FINAL CLASS
TOP 3 YOUTH 10 AND 12. TOP 3 EXPERT 10 AND 12. TOP MMWoman = 13 RIDERS (riders not replaced if selected twice)+ top 10 international riders to be selected!

May race any bike that adheres to the MM10A/E and MM12A/E rules, riders qualified with a 10 inch class can race the World Final with a 12 inch bike!

Special Note: All riders will be allowed to compete in multiple classes; however any rider who finishes on the podium of an Amateur Class (1st, 2nd or 3rd) will not be allowed to finish on the podium of an Expert Class (1st, 2nd or 3rd). If this happens, the Expert Class #1 Plate & Prize Money will be awarded to the next place rider in the respective Expert Class.

TOP 10 RIDERS OF BOTH EXPERT CLASSES OF PREVIOUS YEAR ARE NOT ALLOWED IN ANY OTHER CLASSES BUT EXPERT CLASSES. SAME GOES FOR PREVIOUS MMSX CHAMPIONS AND MX/SX/AX NATIONAL CHAMPIONS!

2011 - 10E & 12E Top 10