Gavin Trippe

[1][7][8] Since 2007 Trippe worked to create a single cylinder racing class with low barriers to entry for amateur racers and young riders.

[2] Trippe introduced European-style 500 cc motocross racing to the US in the early 1970s,[4][11] creating an event at Carlsbad, California which grew into a major international venue.

[5] In 1973, his company, Trippe-Cox Associates, secured the sponsorship of leisure apparel maker Hang Ten International,[5] and the event became the Hang Ten Carlsbad United States Grand Prix (USGP), run under the auspices of the American Motorcyclist Association (AMA), and sanctioned as a Grand Prix event by the Fédération Internationale de Motocyclisme (FIM).

[5] For the race, Trippe-Cox Associates made improvements to the Carlsbad facility, including new water sprinklers, fencing, spectator bridges and billboards.

[18] The machines are motocross-style motorcycles, but with smoother, road race style tires, though in the beginning 750 cc Harley-Davidson flat trackers competed as well.

"[18] Trippe began thinking that, "The huge mass doesn't know the difference between dirt track, motocross and road racing."

[21] Trippe proposed the creation of a new US single cylinder road racing class based on repurposed 450 cc (27 cu in) motocross bikes.

Trippe had been lobbying for the creation of a Formula 450 class because it would be more affordable to rookie and under-21-year-old riders, compared to 600 cc supersport sport bike racing.

The frame, subframe, swing arm, motor and transmission are all stock, but the wheels, tires, suspension and bodywork have all been modified for on-track use and general skulduggery.

"[22] After a few years of development and testing, Formula 450s became motocross bikes which had been converted to road racing by installing 17-inch wheels, larger front brakes, clip on handlebars and aerodynamic fairings.