There are the 4 License classes in the International Roll Racing Association.
The C1 License includes 2 motorcycle racing classes.
Class 1 (C1) License – 156mph or faster
Any 4 Wheeled Vehicle that is all motor or uses forced induction.
ALL MOTOR – C1MA
Any Motorcycle That Doesnt Utilize a Turbo Charger, Super Charger or Nitrous Oxide.
UNLIMITED – C1MU
Any Motorcycle Utilizes a Turbo Charger, Super Charger or Nitrous Oxide.
Class 2 (C2) License – 155.99mph to 140mph
Class 3 (C3) License – 139.99mph to 120mph
Class 4 (C4) License – 119.99 mph or slower