Different strokes

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This year MotoGP has some new Technical rules written to encourage smaller engineering outits to create cheaper machines. The idea of these CRT bikes (for claiming rule Team) is to help free MotoGP from the stranglehold of the major manufacturers. Cosworth already has engineers looking into the possibility of creating a CRT engine.

If the renowned British firm does get back into bikes, let’s hope it’s learned from its previous adventures on two wheels about the perils of attempting to translate car technology to motorcycles.

Forty years ago Cosworth had a rather grim episode with Norton. The already struggling British marque was desperate for a new engine to replace its ageing commando twin that had its origins way back in the 1940s. Norton owner Dennis Poore – a WWII RAF pilot and sometime racing driver who drove an ex-Nuvolari Alfa Romeo – thought he had found the answer in Cosworth’s hugely successful DFV Formula 1 engine.

This was the plan: take two cylinders from the 3-litre V8 to create a 115-horsepower 750cc parallel twin that would give the booming Japanese industry what for. easy, in theory at least.

The four-valve top end might have been a winner but the rest of the engine was not. Norton christened its Cosworth 750 the challenge, and it was certainly that. Despite personal input from DFV designer Keith Duckworth the engine turned out to be too big and too heavy and was beset with all manner of problems.

The project began in 1971 but it was autumn 1975 before the challenge made its race debut, at the season-ending Brands Hatch international. Dave Croxford – who had campaigned the commando-powered John Player Norton with some success – had a horrible time on the lardy contraption (above).

“It was just a bloody nightmare, one and a half seconds slower than the old bike,” recalls Crox, a loquacious londoner and one of bike racing’s greatest characters. “It was rideable out of the box and quick in a straight line, but then you got to the corners… when you shut it off, the thing would lock the back wheel. It nearly had me off a couple of times, so when we went testing at Snetterton I went out in the wet and said to the guys, look, I’ll go past the start/finish, come up to the first corner and I’ll roll it off and you’ll see what happens. So I roll it off, it locks the back wheel and I go down the road. Told you!”

Norton went bust in November 1975, the challenge struggling into the following season funded by little more than contributions from patriotic enthusiasts. But after three more disastrous outings at Imola, Brands and the Isle of Man TT, the venture was over.

Twenty six years later cosworth was back in bikes, at the dawn of the four-stroke MotoGP era. This time the firm’s expertise had been sought by Italian factory Aprilia, best known for its successful Grand Prix two-strokes. Aprilia wanted Cosworth to create a three-cylinder 990cc engine – to set it apart from the Japanese fours – packed with F1 technology. And that is exactly what it got.

Aprilia’s RS3 cube was the first MotoGP engine to feature pneumatic valves, ride-by-wire throttle, dry-sump lubrication and a tiny F1-style carbon clutch. like the challenge, the cube was fast in a straight line – at the 2002 Italian GP it became the irst MotoGP bike to crack 200mph – but was otherwise hard to handle. Good part-throttle performance is vital in bike racing and this is what the somewhat brutal engine lacked. Texan colin edwards, who raced the cube in 2003, gave this graphic description of what it was like to ride. “You take a bull, you cut off its balls, dangle them in front of its face, then you climb on its back…”

During its three seasons in MotoGP the aprilia never even got close to the podium. a new bike was tested in 2004 but, as with Norton before, aprilia was struggling financially and when the company was bought by the vast Piaggio concern the MotoGP project was shut down.

Mat Oxley