Sportsman

Sportsman classes are open to four-stroke motorcycles, built by a recognized motorcycle manufacturer for street use up to December 31, 1972. Like-design models also are permitted. Classes are 350, 500 and 750cc. 10.5.1 Among the eligible Sportsman 350 motorcycles are: • BSA, all models up to 350cc • Ducati, all four-stroke models up to 350cc • Harley-Davidson, all four-stroke models up to 350cc • Honda, all four-stroke, maximum two-cylinder, street models up to 350cc built prior to December 31, 1972 • Norton, all street models up to 350cc • Triumph, all street models up to 350cc 10.5.2 Among the eligible Sportsman 500 motorcycles are: • BMW R50/5 • BSA, all 500cc models • Ducati singles to 500cc • Honda 450 up to December 31, 1972 • Moto Guzzi 500cc up to December 31, 1972 • Norton, all 500cc street models • Triumph, all 500cc models 10.5.3 Among the eligible Sportsman 750 motorcycles are: • BMW R75/5 • BSA, all 650/750 • Ducati 750 round case Sport or GT (no Desmos) • Honda CB750 SOHC, limited to 28mm non-smoothbore carburetors • Laverda (SFC must compete in Formula 750) • Moto Guzzi V-7 Sport or 750 S • Norton, all 650/750 models (except short-stroke) • Triumph, all 650/750 • Yamaha XS650, including 750-kitted 10.5.4 REQUIREMENTS AND MODIFICATIONS FOR SPORTSMAN a) The frame must be a pre-’73 production type (period tubing type). Frames by Trackmaster, Champion and Rickman are permitted; “Rob North” or Rickman roadrace types are not. b) The production street engine must be used. c) The piston stroke may not be changed. d) Weslake cylinder heads, or any other than stock, are not permitted. However, it is permissible to use a twin-carb head if it will interchange with no modifications (e.g., Triumph TR6 and T120). e) Exhaust pipes may be changed or moved for more ground clearance. TT pipes are allowed. f) Wheel rim diameter must be at least 18 inches and cannot exceed WM3 (2.15 inches) front and WM4 (2.5 inches) rear. WM4 (2.5 inches) front rims and WM5 (3.0 inches) rear rims are permitted on 750s only. g) Gearboxes may have up to five ratios. h) 350 and 500 Sportsman machines must use drum brakes. i) No fairings or streamlining allowed on Sportsman motorcycles.