Grand Prix: Classes, Eligibility

12.1.7 POST VINTAGE 100cc: 88-100cc two-stroke and 88-125cc four-stroke motorcycles manufactured as up to 1984 model-year machines, and like-design. All two-stroke motorcycles in this class must have been manufactured 100cc orsmaller displacement bikes. And four-strokes manufactured as 125cc or smaller displacement bikes. Maximum engine displacement for two-strokes is 100cc, plus allowable overbore. Maximum engine displacement for four-strokes is 125cc, plus allowable overbore. Electronic ignitions and reed-valves are allowed. Hubs and forks from any Post Vintage eligible machine are permitted. Suspension travel is not limited. Disc brakes are not allowed. Eligible Machines to include: • Suzuki TM & RM to 1981 • Yamaha DT, MX & YZ to 1983 • Hodakas all 100cc models • Honda XR 100 & XL 125 to 1985 and like design • Kawasaki KE 100

12.2 GRAND PRIX - CLASSES AND ELIGIBILITY

The Grand Prix classes are intended to represent the motorcycles that made up the “second generation” long-travel motorcycles generally available in the 1977-81 period (or like design). During this period innovation came rapidly and motorcycles changed dramatically in a fairly short time. For this reason, the Grand Prix Classes follow a formula rather than a specific year cutoff. 12.2.1 TECHNICAL SPECIFICATIONS: Gran Prix-class motorcycles feature technology later than that found in Historic, but do not include linkage-type rear suspensions, liquid-cooling, or disc brakes. There are no suspension-travel limitations, but upside-down forks are not allowed (see the Ultima classes). Aftermarket frames and forks are permitted, and many were available during the intended time frame of the classes. If there is a question regarding the eligibility of any component, please submit a Request for Eligibility Form found near the back of this Handbook. 12.2.2 GRAND PRIX 125: Certain post-1977 motorcycles 88-125cc. The year of manufacture is not important, as long as the motorcycle meets the class formula. • 1978-’83 Husqvarna 125s are allowed • 1978-’80 Yamaha, Honda, Suzuki, Can-Am and KTM 125cc motocrossers are allowed • 1981-model Honda, Suzuki, Yamaha, KTM and Kawasaki models are prohibited. See the Ultima class 12.2.3 GRAND PRIX 250: Certain 126-250cc post-1977 motorcycles. The year of manufacture is not important, as long as the motorcycle meets the class formula. • 1978-’81 Can-Am Qualifier and MX, up to MX6, are allowed • 1987-’89 CZ 250 is allowed • 1978-’83 Husqvarnas are allowed • 1978-’81 Maico 250s are allowed • 1978-’80 Suzuki, Yamaha, Honda motocross and enduro models are allowed • 1981 Yamaha YZ250 is allowed • 1980 and later Kawasakis are prohibited. See Ultima class • 1981-model Honda and Suzuki are prohibited. See Ultima class