Formula 1
Chassis: Street or Dirt
Two-stroke engine: Air-cooled up to 60cc, water-cooled up to 50cc
Four-stroke engine: Up to 100cc
Engine mods: Must use stock head configuration, cannot exceed
max displacement
Chassis mods: Unlimited
Bump-up class: Formula 2
Examples: Honda XR or CRF-50, NSF-100, Yamaha TTR-90

 

Formula 2
Chassis: Street or Dirt
Two-stroke engine: Up to 65cc Four-stroke engine: Up to 125cc
Wheels: Any size
Engine mods: Must use stock head configuration, cannot exceed
max displacement
Chassis mods: Unlimited
Bump-up class: Thumper (for 4 strokes)
Bump-up class: GP (for 2 strokes)
Examples: Yamaha TTR-125, Honda CRF-100, Kawasaki KX-65

 

Thumper
Chassis: Street or Dirt
Two-stroke engine: Not allowed
Four-stroke engine: Up to 156cc air cooled
Engine mods: Must use stock head configuration, cannot exceed
max displacement
Chassis mods: Unlimited
Bump-up class: GP
Examples: Honda CRF-150F, Yamaha TTR-125 with 150 kit
installed

 

GP
Chassis: Street or Dirt
Two-stroke engine: Up to 85cc Four-stroke engine: Up to 156cc
Engine mods: Must use stock head configuration, cannot exceed
max displacement
Chassis mods: Unlimited
Bump-up class: None
Examples: Kawasaki KX-85, Honda CR-85, Yamaha YZ-85
Honda CRF150R

Super Lites
Chassis: Dirt only
Two-stroke engine: Up to 125cc
Four-stroke engine: Up to 250cc
Engine mods: Must use stock head configuration, cannot exceed
max displacement
Chassis mods: Unlimited
Examples: Honda CRF-250, Kawasaki-KX-100, KTM 125-SX

SuperMotard
Chassis: Dirt only
Two-stroke engine: Up to 500cc
Four-stroke engine: Up to 650cc
Engine mods: Unlimited, cannot exceed max displacement
Chassis mods: Unlimited
Examples: Honda CRF-450, Yamaha YZ-450F, KTM 450-SMR