This page is taken directly from the rule book – read the entire rulebook here.

Finding a class to ride in

Cascadia Supermoto wants you to race! If you bring a motorcycle that meets the minimum restrictions listed, we will find at least two classes for you to ride in.

The class structure has been designed to make sure that every rider has at least two classes available for them, and most should have three. If you cannot find two classes to ride in, please talk to registration or the race directory and they will make exceptions as needed to find you a second class to ride.

Restrictions for all classes

All classes have the following restrictions:

  • No sportbike-style motorcycles (i.e. fairings and clip-ons) except in the minibike and scooter classes.
    Sorry, this is a restriction imposed by one of our venues, and means that no Ninja 250s are allowed.
  • No twin-cylinder engines over 580cc unless riding in the Heavyweight class.
  • No engines with more than two cylinders unless riding in the Heavyweight class.

New class proposals

Cascadia Supermoto is open to new classes! If five or more riders wish to create a new class and are prepared to run in it, as long as it meets the general restrictions above, we will add the new class into the schedule immediately. New classes may not grid separately, but they will be scored separately and have their own championship awarded.

Sprint/Supermoto Classes

Open Supermoto

This class is for experienced racers on unlimited machinery.

You do not have to be a pro to ride this class! This is the class for the club #1 plate, and any supermoto rider who has some race experience should be comfortable riding in this class and competing for club #1. This is an amateur race series, not a pro series, and Open Supermoto is not a money class.

  • Unlimited displacement
  • Unlimited modifications
  • Novice riders are prohibited from entering this class.


This class is for slower riders on any machinery.

  • Unlimited displacement.
  • Unlimited modifications.
  • Open to Novice-level riders only. Riders cannot enter this class if entered in Open SM.
  • Riders with previous racing experience should not enter this class. Race direction may move riders out of this class to Open Pro at their discretion. Don’t be a sandbagger.

450 Supermoto

  • Unlimited modifications.
  • Displacement limits of
    • 450cc or less for water cooled four-stroke engines
    • 300cc or less for two-stroke engines.
    • Unlimited displacement air or air-oil cooled four stroke engines

250/400 Supermoto

  • Unlimited modifications.
  • Displacement limits of
    • 250cc or less for four-stroke water-cooled engines, any modifications
    • 400cc or less for four-stroke water-cooled engines with 100% OEM rims and brakes (AKA: DRZ-400S)
    • 220cc or less for two-stroke engines.
    • 480cc or less for air-cooled engines


This class is for lower-performance Supermoto or dual-sport bikes, or motocross bikes running OEM wheel sizes and brakes.

  • Unlimited displacement.
  • Restricted This class is for motorcycles running stock (OEM) wheels and brakes with lower-power engines. This class is intended for motorcycles such as:
    • Motocross bikes with street tires on the OEM 21” front and 18”/19” rear rims.
    • Street-legal supermoto bikes such as the Suzuki DRZ400SM and Yamaha WR250X.
    • Dual-sport motorcycles such as the Kawasaki KLR650 or Honda XR600L.
    • Any other street-legal dual sport motorcycle that meets the minimum requirements for all race bikes.
  • NO KNOBBIES. Sorry, they destroy the dirt sections. If unclear on whether a tire would be considered a knobby, please contact tech before the race. As a rough guide, nothing chunkier than a Pirelli MT-60 will be allowed.
  • This class EXCLUDES high-performance factory supermotos such as KTM SMRs, Aprilia 450/550 SXVs, KTM 690s, etc. even if they are street-legal in Washington or Oregon. This class is intended to be competitive for motorcycles that are not heavily modified or specifically manufactured for Supermoto racing. Race direction may exclude models from this class at its discretion, or allow excluded motorcycles and riders to participate on a case-by-case basis, depending on the skill and experience of the rider.


  • Unlimited displacement.
  • Unlimited modifications.
  • This class will run ONLY the asphalt portion of the course.
  • Special rules apply for Heavyweight bikes that exceed general displacement maximums – see the Heavyweight class rules for details.


NOTE: For mini endurance classes, please see the mini endurance rulebook!

  • 230cc or less for air cooled four-stroke motorcycles
  • 165cc or less for water-cooled four-stroke motorcycles
  • 85cc or less for two-stroke motorcycles
  • Unlimited frame/chassis modifications

Junior Supermoto / Junior Minibikes

  • Legal for all scooters, four-stroke motorcycles with 230cc or less displacement, two-stroke motorcycles with 85cc or less displacement.
  • Riders must be 15 years old or younger to enter this class.


This class is for big-bore Supermotos such as the KTM 690 SMC, Husquvarna 701, and also for ultra-heavyweight motorcycles such as the Ducati Hypermotard, Aprilia Dosoduro, Honda Africa Twin, or large-displacement flat track bikes such as XR750s, TZ750 two-strokes, etc that exceed the maximum displacement listed in Section 5.1 of the rulebook.

  • Unlimited cylinder count & displacement – Motorcycles with 2+ cylinders and greater than 580cc displacement are OK in this class; this is an exception to the maximums listed above in “Restrictions for all classes”.
  • No clip-ons, no fairings. Motorcycles must use an offroad style handlebar.
  • Unlimited chassis, suspension, and engine modifications.
  • Entrants in the Heavyweight class may also ride Asphalt Only if their motorcycle exceeds displacement/cylinder limits for the class, but they must finish their Heavyweight heat race to be allowed into the Asphalt Only heat/main. Only ultra-heavyweight motorcycles like the Ducati Hypermotard are affected by this rule.