Just 40 years ago, Ducati was known for its outdated desmodromic singles and little else. On April 23, 1972, Paul Smart and Bruno Spaggiari debuted Ducati's new desmodromic 750 v-twin with a 1-2 victory at the Imola 200 Mile Race.

They beat Giacomo Agostini's MV Agusta, plus the best that Honda, Kawasaki, Suzuki, Triumph, BSA, Laverda and Moto Guzzi could offer.

The famous victory set Ducati on a course that saw its big desmo V-twins dominating superbike racing for four decades. The official factory reserve bike from that day is coming up for auction, with bidding expected to finish beyond EUR150,000.

This is a significant example of the first of a new breed of Ducati and its desmodromic valve system.

Horsepower has a direct relationship with the revolutions per minute that an engine can turn. There are many factors which conspire to limit the rpm an engine can reliably achieve, but valve gear has had the greatest influence over the last century.

The inlet and exhaust valves in an internal combustion engine are usually opened mechanically, and closed with a spring. Springs worked well at low and medium rpm, but at high revolutions, the spring has trouble pushing the valve down fast enough.

Hence the desmodromic system, which mechanically closes the valve, was tried by many companies with varying degrees of success in numerous racing cars from the 1920s onwards.

The most famous vehicle to have ever used this system, which both opens and closes the inlet and exhaust valves mechanically, was the Mercedes Benz Silver Arrow which won two world Formula One championships and countless other races in the hands of the likes of Fangio and Stirling Moss.

As with Formula One racing these days, top flight car racing was a testbed of some remarkable future technologies and the V8 W196 which debuted in 1954 featured desmodromic valve gear and fuel injection.

The car's 100 mph average at the Mille Miglia (held on public roads in Italy in ) is still one of motorsport's favorite bedtime stories.

Enzo Ferrari, whose cars were being beaten by the Silver Arrows, is reported to have discussed the advantages of demodromic valve gear at length with Ducati's designer Fabio Taglioni during the mid-fifties, and it's hence not surprising that Taglioni decided to give the system a try in Ducati's 125 single cylinder racing engines.

The engines were fast, and they could rev several thousand rpm faster than their counterparts but they were brittle. In the late fifties Ducati desmodromic singles won four Grands Prix - three in 1957 when the bike could easily have won the 125 title, and once in 1958, in the hands of an up-and-coming British rider named Mike Hailwood.

In the subsequent few years the multi-cylinder 125cc race machinery of MV Agusta and Honda rendered the 125cc single uncompetitive of paved race tracks and the project was shelved. Ducati's Fabio Taglioni learned a lot about metallurgy and even more about the reliability and perfromance of the desmodromic system though the continued production of Ducati's road bikes.

He also knew for certain by then that the mechanical valve system enabled the desmo motor to rev far harder than engines with conventional valve trains, which were limited in their ability to rev by valve bounce (the springs could not close the valves fast enough).

There's a downloadable PDF booklet (9.3 MB) on the Ducati website which plots the history of Doctor Taglioni and the evolution of the Ducati desmodromic valve system and its racing bikes and it's well worth a read - on the cover of the book is Taglioni with Smart and Spaggiari. This was Taglioni's finest moment, and despite more than 50 world titles, probably Ducati's finest as well.

The bike to be auctioned is identical in ever way to the bikes which went one-two that day, and had there been reliability issues with any of the works machines, this bike would have been substituted.

It is being auctioned as part of the disbursement of the Saltarelli Ducati Collection which represents one of the largest private collections of Ducati motorcycles ever to be offered at auction.

Spanning the marque's full history from road to racing machines, the 100-bike collection was carefully selected over the past 30 years by lifelong enthusiast Carlo Saltarelli, an ex-Ducati factory test rider, racer and owner of a Ducati dealership.

The catalogue describes the bike as an "immensely-desirable works 1972 Ducati 750SS 200 Miles Imola Racer" - it is actually also the first Ducati v-twin as we know it.

There had been a 500cc v-twin race bike used the previous year, but this was one of the original eight Ducati 750s prepared for the first race - it produces 80 bhp (60 kW) at 8,500 rpm. This bike would undoubtedly have felt the hands of Taglioni himself.

Which makes the estimated price of EUR150,000 to EUR200,000 seem extraordinarily cheap. It will be offered without a reserve price on May 11 next year by RM auctions.

Editor's note: This 1972 Ducati 750 200 Miglia Imola Corsa Replica sold for EUR €70.200 (US$100,135 based on the exchange rate of 1.426 on the day of sale - May 11, 2012).

To be auctioned on Friday, May 11, 2012

Sold for €70.200

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