Novice Historic Production

j) Sportsman 750 machines may use one front disc brake; period-type fixed steel disc, maximum diameter 12 inches, two-piston caliper. Sportsman 750 machines may use a period-type rear drum brake or period-type rear disc with a two-piston caliper. k) Front fork stanchions must be no larger than 38mm unless supplied as OEM on that motorcycle. Forks with external adjusters are prohibited. All forks must be of the period, or like design. l) Note: See requirements of all road racing motorcycles in Section 9.

10.6 NOVICE HISTORIC PRODUCTION

Novice Historic Production is open to production street machines built up to 1978-model-year, as determined by the frame and major component parts, and like design. Machines must use original unmodified, OEM frame, swingarm, fork and handlebar mounts. Unnecessary tabs and brackets may be removed, but gusseting (no strengthening) can be added; no geometry may be altered. Gas tank, seat pan and fender must be OEM, equivalent, or replica replacements. Fenders must be untrimmed. Engines must be original OEM bore and stroke, regardless of displacement (plus allowable overbore, as described in rule 9.7.2.c). All engine and transmission components and assemblies must maintain OEM dimensions and limits. Aftermarket parts are allowed only if they are a direct replacement for the originals. Modifications for reliability (e.g., starter removal or ignition replacement) or to resolve non-performance issues (e.g., cam chain tension or oil pressure) are permitted. Classes are Lightweight (four-strokes up to 500cc, 250cc two-strokes and specific 350cc two-strokes listed with an asterisk (*) below) and Heavyweight (four-strokes up to 750cc and 350-500cc twostrokes); three- or four-cylinder DOHC machines are not allowed. 10.6.1 RIDER ELIGIBILITY This class is intended for novice and returning non-professional veterans, not seasoned racers. At the referee’s discretion, riders who are obviously too fast for the Novice Historic Production class may be moved to a more appropriate class, such as Sportsman. This does not exclude Historic Production riders from racing another bike eligible for any other class. See section 3.4. 10.6.2 Eligible Novice Historic Production Lightweight motorcycles include: • Aermacchi/Harley-Davidson 350 • BMW R50 • Bridgestone 350cc twin* • BSAA50, B50 • Bultaco 250 Metralla • Ducati 450 • Honda 350 two- and four-cylinder • Honda 400 four-cylinder • Honda 450 two-cylinder, must use OEM CV carbs or replacements no larger than 28mm • Kawasaki A1 250cc, A7 338cc twin* • Moto Guzzi 500 • Suzuki T250, X-6 and T305 twin* • Triumph 500 • Yamaha 250 (up to RD250)

10.6.3 Eligible Novice Historic Production Heavyweight motorcycles include: • BMW R75/5 • BSA, all 650/750, two- or three-cylinder • Ducati 750 round-case Sport or GT (no Desmos) • Honda 750 four-cylinder • Honda 500T two-cylinder • Kawasaki 500 two-stroke • Laverda SF750 (SFC must compete in Formula 750) • Moto Guzzi 750 (V7 Sport must compete in Formula 750 or Sportsman 750) • Norton, all 650/750 (except short stroke) • Suzuki 500 two-stroke • Triumph, all 650/750 with two-valve head; two- or three-cylinder • Yamaha R5 and RD350/400 air-cooled two-stroke

10.6.4 REQUIREMENTS AND MODIFICATIONS FOR HISTORIC PRODUCTION a) CARBURETORS: Must be OEM and same type (i.e., if originally CV, must use CV), no larger than the original OEM bore size. (Restrictors may be introduced to ensure parity of performance.)Air intake:Airboxes and/or air filters may be removed. No performance-increasing devices may be added (velocity stack, scoops, etc.)Aftermarket foam or mesh-type air filter(s) may be added. b) EXHAUST SYSTEMS: Four-stroke engines must have the same number of pipes as provided on that motorcycle, (i.e., two-into-two, four-into-four, or three-into-two for three-cylinder engines). Exhaust pipes may be aftermarket, may be tucked or raised for ground clearance, and must have effective silencers. Two-stroke engines may use production street exhausts from the time period, any manufacturer. Expansion chambers are allowed provided they are constructed in keeping with the vintage design scheme shown as illustrated. The system will be constructed with a constant diameter chamber then tapering to constant diameter head and tail pipes of OEM dimensions. The attached silencer will limit sound to 103dB.

c) BRAKES: Front and rear may be upgraded to Sportsman 750 specifications in the Heavyweight class only. Lightweight-class machines must use OEM brakes as fitted on that make and model year. d) RIM SIZES: Replacement rims must be the same diameter and material as

OEM. Maximum allowable rim widths are WM3 (2.15 inches) front and WM4 (2.5 inches) rear. e) Sidestands and centerstands must be removed. f) CONTROLS AND FOOTRESTS: Controls: Handlebars must bolt to the stock locations. Clubman bars are allowed. Footrests may be trimmed down or raised for ground clearance; rearsets may be used. g) Lighting equipment must be removed or taped over to the tech inspector’s requirements. h) FAIRINGS AND BODYWORK: Fairings of any type are not allowed. Gas tank, seat and fenders must be OEM equipment or period replacements. No modern

“GSXR-style” bodywork will be allowed.