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Monday, 24 September 2007

Neil McMahon’s story in today’s Sydney Morning Herald (‘Ever in a hurry, Casey conquers the world’) ignores a salient point: it’s Ducati’s first MotoGP win in 34 years. Of course, Mick Doohan’s comment that it’s “like a 21-year-old Aussie kid beating Tiger Woods at golf or Roger Federer at tennis”, is apt.

Nevertheless, to blithely ignore team Ducati’s engineers and their achievement with a truly marquee brand, is obtuse in the extreme.

The Desmosedici engine responsible for the win is unique in the motorcycle world, and is based on the legendary Desmodromic, two-cylinder, two-valve-per-cylinder unit that powered my 900 Dharma (pic) in the mid-80s.

Even then, the technology was outdated and although the Ducati offered an unparalleled riding sensation, with torque allowing a virtually flat curve even when accelerating from below 1000rpm, it couldn’t compete with a zippy, Japanese four-cylinder powerhouse for sheer acceleration.

The new, liquid-cooled, 90-degree, V4, four-stroke unit Stoner is mounted on uses a Desmodromic DOHC valve action system, which has a belt running from the drive shaft to the valve cam at the top of each cylinder pair.


In the Desmodromic system, there is a valve cam but no spring. Each valve is lifted up and down ("positive action") by a special arrangement that includes a cam and that is activated by a rapidly-spinning rod. The rod runs from a gear located at the end of the drive shaft to the top of each cylinder which, as with the cylinder configuration of the modern exponent, is oriented at an angle of 90 degrees to its twin.

The rods are mounted on the other side of the bike from that shown in the pic. The engine is air-cooled using fins.

Ducati’s cachet is only equalled among bike enthusiasts by the Hog, the preferred vehicle of motorcycle gangs. Aspirational bike freaks want a Ducati because of its elegant European styling, minimal decal action, and superb exhaust sound.

The fruity roar of a classic Ducati as it rumbles down the street is without parallel, especially when fitted with premier after-market tubes. Because the current models use a four-cylinder unit, the effect is not quite the same. But it’s still considered a ‘good’ sound when compared to the peaky scream produced by comparable Japanese models.

If you go to the Ducati website, you can open a sound file to play the tone of a modern Ducati going full-bore.

Ducati has built bike engines in Bologna since 1946. The company had made radio components since the 1920s. The first ‘sport’ motorcycles appeared in 1956. In 1958 the first Desmodromic engine was marketed.

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