450 Super Single Project

Roadracing Revolution?


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Could a new roadracing series based around converted 450cc dirtbikes be the tonic to invigorate entry-level roadracing in this country? A couple of famous names in the industry think so.

This project is the brainchild of Gavin Trippe, the guy who came up with the exciting race series Superbikers that aired on ABC-TV from 1979-1985. Using a course consisting of both dirt and pavement, Superbikers is the progenitor of the recent supermoto movement.

The number of 450cc four-stroke dirtbikes sold in America over the past several years is pushing 100,000, and Trippe believes that the deep pool of bikes can be the basis for affordable roadracing machines, eventually spawning a new class in a national race series.

The concept is to take contemporary single-cylinder 450cc dirtbikes and, with the addition of a roadracing front end, streetbike brakes and wheels and 250GP-style skin, create a new spec class for entry-level roadracers. We think “MonoGP” has a nice ring to it.

 Roland Sands Design converted a couple of dirtbikes into roadrace machines to explore the concept of creating a new entry-level racing class.

Helping realize Trippe’s idea is famous custom bike builder Roland Sands. Now helming his eponymous company Roland Sands Designs (RSD), Sands is also a former AMA 250GP class champion who has extensive roadracing experience. He’s brought Trippe’s concept to life by converting a few 450cc dirtbikes to lightweight roadracing machines that are about the size of a two-stroke 250cc roadracer.

In Trippe’s grand scheme, the bikes in this class would use the guts of the dirtbikes, including the stock frame, swingarm, subframe and engine mounts. Aftermarket wheels would be used (3.5-inch front, 4.5-inch rear), with only a single disc brake at both ends. Replaceable items include the rear shock and rear-set footpegs. Spec bodywork would give it the proper roadracing shape, and Trippe envisions the bikes should be painted in factory color schemes (red for Honda, blue for Yamaha, etc.) so that race fans can easily tell them apart. In the engine compartment would reside the 450cc dirtbike motor that can be tuned to produce nearly 60 hp with about $1000 worth of work.

Sands has at this point built a few versions of this new breed of roadracers. He built one example out of a Kawasaki KXF450F, adding a ZX-6R fork and triple clamps and RSD wheels. A custom exhaust exits out of the top of the tailsection.

Sands says the result is chassis geometry nearly identical to a 250cc GP bike, with a 22.9-degree rake angle, 98mm of trail and a 54-inch wheelbase. Expect a very modest 250-pound dry weight.

Thus far, these bikes have been tested at Streets of Willow and, more recently, at the season-ending AMA Superbike race at Laguna Seca. As you’ll see in the accompanying video, riders who have ridden these machines include 1993 500cc World Champion Kevin Schwantz and 15-year-old teen sensation Elena Myers.

 

So, could this be the next big thing in roadracing? Trippe says that a competitive bike could be built for less than $10,000. He also anticipates using spec fuel, exhaust systems with sound limits and a bike/rider combined weight limit to ensure parity.

Trippe plans to host a 10-race series in WERA competition in 2008, perhaps joining the AMA Superbike series as a feeder class in ’09. More information about the project can be found at 450moto.com.

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Are converted 450cc dirtbikes like this concept a glimpse of roadracing’s future?

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