Mini Classes


Mini classes are for endurance events only. For Supermoto/sprint races, there is only one minibike class at this time.

All mini classes will start together for endurance events.

For the full set of mini endurance rules, please see the mini endurance rulebook.

Class Overview

  • Formula 100
  • Mini Sportsman / Grom
  • Mini Superbike
  • Open

Formula 100

This class is intended as a fun and inexpensive endurance class for small, four-stroke off-road motorcycles with minimal additional modifications, typified by the Honda XR100. Attempts to violate the spirit of the class by rules-lawyering will result in the team being bumped to the Open class by race direction.

  • Frames are limited to small-framed four stroke motorcycles originally sold as off-road motorcycles. Examples

    • Honda XR100
    • Yamaha TT-R 125 (small wheel drum brake model only)
    • Kawasaki KLX-110
    • Suzuki DR-Z 125
  • ONE OEM wheel may be changed for a non-OEM wheel. No other modifications to wheels (disc brakes, etc)
    are permitted. 17” wheels and GP tires are not permitted. 12” scooter wheels are not permitted.
  • Front aftermarket springs may be installed and fork oil weights may be changed, but no other front
    suspension modifications are permitted.
  • Rear aftermarket springs may be installed, but no other rear suspension modifications are permitted.
  • Engine modifications are limited to:
    • Displacement increases up to the class limit
    • Aftermarket replacements for OEM parts that are less expensive than the OEM parts they replace.
    • Aftermarket air filter and exhaust systems.
  • Compression ratios must remain the same as OEM.
  • Chassis modifications that will improve performance (braces, etc) are not permitted.
  • Displacement limit of 125cc for all motorcycles. Two-stroke motorcycles are not permitted in this class.
  • Motorcycles and models not listed or that don’t exactly fit will be considered for inclusion on a case-by-case basis by race technical direction. Encouraging close, fair, and cheap racing is the goal of the class.

Mini Sportsman

A class for street-legal minis such as Honda Groms and similar bikes, including the Kawasaki Z125, SSR 125, etc.

  • Max 125cc air-cooled engine.
  • 12” rear, 12” or 14” front wheel.
  • Must be sold as street legal, or approved as equivalent to such by registration and technical direction. The
    SSR-125 is approved for this class.

Mini Superbike

This class is for small-framed motorcycles that have been heavily modified. Examples include the Yamaha YSR50, Honda NSR50, Metrakit, Kayo MR125, modified XR100/TTR-125 motorcycles, Suzuki DR-Z 125L, Honda CRF150, and Kawasaki KLX-140. It is roughly equivalent to Texas Mini GP Formula 6.

  • 2 stroke air cooled: 60cc max, any other modifications ok.
  • 2 stroke water cooled: 50cc max, any other modifications ok.
  • 4 stroke air cooled: 150cc max, any other modifications ok.
  • 4 stroke water cooled: 100cc max, any other modifications ok.


  • Unlimited modifications.
  • Displacement limits:
    • 230cc or less for air-cooled four-stroke engines
    • 165cc or less for water-cooled four-stroke engines
    • 85cc or less for two-stroke engines

Addition of classes will depend on rider turnout and interest. If you’d like to add a class, please email Cascadia Supermoto and let us know, and come out to the first race.