Phillip Island Challenge

d) All racebikes shall have a plainly-marked, easily-accessed emergency disconnect switch on the handlebar (within reach of the rider with his/her hands on controls), plus a tether fastened to the rider that disconnects all sources of power should the rider become separated from the bike. A documented software/hardware function that disables motive power when the bike is horizontal can replace the tether. e) Racebikes shall have an audible horn operated by a handlebar-mounted button. f) All racebikes must conform to Handbook Sections 9.3, 9.4 and 9.8.

10.20 PHILLIP ISLAND CHALLENGE

Mission Statement: To allow entrants of Team USA to have a place to race and exhibit the machinery in preparation for the International Challenge held annually at the Phillip Island Classic, in Phillip Island, Australia. To provide machinery of large displacement vintage era engines to have an organization to race with that currently does not exist anywhere else. **All rules stated below pertain to all motorcycles including 4-stroke and 2-stroke machines**

a) PERIOD: The period of machinery eligible includes all motorcycles engines up to and including the year 1984. Frames may be production, aftermarket, or custom, all built in a safe and workmanlike manner. b) ENGINE CAPACITY: The following displacements are approved: 1. 2-valve engines: 700cc to 1300cc 2. 4-valve engines: 700cc to 1300cc 3. Two-cylinder engines: 700cc to 1400cc c) WHEEL SIZE: The following rim widths apply: 1. Front wheel maximum rim width of 3.5 inch 2. Rear wheel maximum rim width of 5.5 inch d) BRAKES: The following restrictions apply: 1. Two and four pot calipers are allowed 2. Maximum brake rotor size of 340mm 3. Wave rotors are NOT permitted 4. Radial brake master cylinders are NOT permitted e) CARBURETORS: 1. Both round and flatslide carburetors are allowed 2. Maximum carburetor bore size of 40mm f) FORKS: 1. Maximum tube diameter of 43mm 2. Upside down forks are NOT permitted g) COOLING: 1. 4-stroke engines must be air cooled only 2. 2-stroke engines can be either air or water cooled h) TIRES: The use of the following is approved: 1. DOT tires 2. Slick tires 3. Wet tires 4. Tire warmers i) ELECTRONIC AIDS: Electronic aids are NOT permitted other than ignition, i.e., no quick shifters or traction control. j) NUMBERS: At least 7-inch-high numbers, block style, clearly visible and legible.