Bike Prep Rules

From Section 4 of the Rules. Please note that these are provided as a convenience; the PDF rulebook is considered authoritative in the event of a discrepancy.

Technical Requirements

Every motorcycle must be certified for racing by the race day technical inspector before being allowed on the track. The tech inspector will mark each motorcycle as approved after examination or will tell the racer how to make their motorcycle ready to race.

If a motorcycle cannot be made ready to race prior to the start of racing, it will not be allowed on the track and the racers will be refunded their entry fees for that day.

The Race Director has final say on whether a motorcycle meets technical requirements and is safe to race.  Disputes between competitors on the legality of a specific motorcycle, application of a class rule or technical requirement, class protests, or concerns about the condition of a competing motorcycle should be taken to the technical inspector or Race Director. Arguing with the technical inspector is not allowed, and may result in other penalties, up to or including ejection from the event, at the discretion of race direction.

Technical Requirements for Racing Motorcycles

Motorcycles must meet the following technical requirements to be allowed on the track. The technical inspector may, at their discretion, allow a temporary fix for a particular race weekend. The rider or crew bringing the motorcycle to inspection must point out any known or potential problems with the machine.

4.2.1 Required safety modifications

    a) Safety wiring requirements (see below) must be met.

    b) Fuel and crankcase vent lines must be routed to one or more catch cans. Catch cans must be made of metal or plastic, no glass or paper catch cans are permitted. Total volume of all catch bottles must be 6 fl oz or greater. Only a case vent catch can is required for EFI-equipped machines. Coolant catch cans are not required.

    c) For motorcycles with clip-on style handlebars, bars must have rounded end plugs at least 1/2” tall. Handlebar ends must not be hollow or ground to a sharp end.

    d) For motorcycles with full handlebars, aluminum handguards/bark busters or lever guards that protect the bar end and attach at two or more points must be installed. Exceptions are street-legal Formula 125 entrants with OEM bars and bar ends and scooters.

    e) For all motard-style motorcycles with folding pegs, hard plastic protective footpeg sliders are required. Sliders must not be made of metal, or have any parts that are made of metal that contact the asphalt. Thin sliders or sliders with protruding/flush bolts will not pass inspection. If it makes sparks, it’s illegal.

    f) For Open-class motard-style motorcycles, front and rear axle sliders with hard plastic caps are required.

    g) For liquid-cooled motorcycles, only water and Water Wetter, Silkolene Pro CCA, VP Stay Frosty, or Evans Trackwater are allowed as coolant. No glycol-based coolants of any kind are permitted, including Evans NPG and Engine Ice.

IMPORTANT: Motorcycles must maintain adequate slider thickness throughout the race and after crashing. Bring extra sliders, especially for motards.

The following equipment must be removed from all motorcycles:


4.2.2 Safety wiring and securement

The following must be secured with safety wire. “R”-clips or cotter pins are acceptable only as noted.

    • Oil drain bolts

    • Oil filter cover bolts

    • Oil fill plugs (wired R-clips are acceptable)

    • External oil filters (using a hose clamp around the filter wired to a hard point).


The following must be clamped or safety wired:

    • Any non-bolted & flexible fluid-carrying lines.


4.2.3 Overall motorcycle condition and preparation

    a) General:

        ◦ Frame, swingarm, and wheels must be true and free of cracks or unsound welds.

        ◦ Spoked wheels must have no missing, broken, bent, or loose spokes.

        ◦ Tires must be in good condition as judged by the technical inspector.

        ◦ Any lights other than a single rear rain light must be taped over completely.

        ◦ All motorcycles must be in a safe, ready-to-race condition as determined by the technical inspector. This means no loose bolts, broken parts, worn chains, or any part or defect on the motorcycle that the inspector believes may present a safety hazard.

    b) Controls:

        ◦ Operational front and rear brakes (Exception: front-brake only classes).

        ◦ Clutch and brake levers must have at least a ½” ball on the end.

        ◦ The throttle must operate smoothly with a positive return to idle when released, meaning the throttle snaps back to idle immediately.

        ◦ The motorcycle must have an operating kill switch.

    c) Fluids:

        ◦ No visible oil or fluid leaks.

        ◦ Only water and Water Wetter, Silkolene Pro CCA, VP Stay Frosty, or Evans Trackwater are allowed as coolant. No glycol-based coolants of any kind are permitted, including Evans NPG and Engine Ice.

        ◦ Vent and overflow lines for oil, crankcase breathers, and fuel must be routed to a catch can or cans. See the safety modifications section for details. Coolant catch cans are not required.

    d) Sound reduction:

        ◦ All internal combustion motorcycles must have a working exhaust muffler that is securely mounted to the exhaust pipe and/or frame.

        ◦ Any motorcycle that is determined to be too loud by race direction will be retired until the sound can be adequately mitigated. A maximum of 95db at 30 meters behind the motorcycle should be used as a guideline.

4.2.4 Equipment variances

Machine-specific variances may be permitted in some cases if equipment is difficult to remove or integral to the machine and it does not compromise safety. Riders or teams wanting a variance must contact race direction prior to the event via email or phone to request one – waiting until race day may result in penalties or being denied entry to the race.

Numbering and transponders

4.3.1 Race number selection/assignment

Race numbers will be selected during the annual member registration process – endurance motorcycles will use the team captain’s race number. Race numbers for  members during race registration on a first-come, first-served basis.

Race numbers may be any number between 6 and 999. Numbers 1-5 are reserved for the previous years’ overall top-5 finishers, if desired. Competition numbers are numeric characters only, alphabetical characters are not permitted.

4.3.2 Race number placement and visibility

All motorcycles must have race numbers, and numbers must be clearly visible from both sides and the front from a distance of 50 feet. 5” high numbers on the sides and 4” high numbers on the front are recommended though not required. Please try to have numbers as clear and legible as possible. If a number cannot be read by scoring during the race, the motorcycle may not be scored or the rider/team will be given an identifying jersey to wear.

4.3.3 Transponders

All races will be scored using Westhold G3 transponders. Riders without transponders may rent them on a first-come first-served basis. 

Any Westhold G3 transponder may be used - MX, Kart, or Car transponders are all compatible with the NWMM timing system.

Westhold G3 MX transponders, mounts, and chargers are available for purchase  directly from Westhold at https://shop.westhold.com/g3-mx-rechargeable-transponder-package/.