Ducati Desmosedici is a four-stroke V4 engine racing motorcycle made by Ducati for Moto GP racing. The series nomenclature is GP with the two-digit year appended, such as Desmosedici GP10 for 2010. In 2006 Ducati made a short production run of 1,500 street-legal variants, the Desmodeci RR.
Ducati abandoned the Grand Prix racing scene at the start of the 1970s. For many years the 500 class was essentially a class for two-stroke motorcycles, an engineering technology that was far removed from the four-stroke road-going machines sold by Ducati. Technical rules changed in 2002, giving priority to four-stroke machinery and turning the 500 class of World Road Racing into the Moto GP Championship. This convinced Ducati to make a much-awaited return to the track in the new Moto GP class.
Ducati history is classically based on 90° V-twinn (or L-twin) engines, using desmodromic valve technology. Initially, Ducati considered the possibility of creating a Moto GP 'super-twin', taking advantage of the Moto GP regulations that give twin-cylinder machines a considerable weight reduction over four, five or six-cylinder bikes. However, analysis indicated that a twin-cylinder engine would not have been able to produce the required amount of power, more than 230hp (170kW), without excessively increasing the number of revs. A twin would have had to rev at over 17,000 rpm, but this would require a very short stroke and a very large bore, as a result producing possible combustion problems.
The basis of the design of the Desmosedici engine therefore is two classical Ducati L-twins next to each other, making a Double L-twin with two-cylinder Stroking at the same time (also called Twin Pulse). With four valves per cylinder, the total number of valves is sixteen ? Desmosedici means desmodromic distribution with sixteen valves shortened in Italian.
Design had started in 2001, the bike was unveiled at the 2002 Italian GP at Mugello, for use in the following seasons Moto GP World Championship. Vittoriano Guareschi, the Ducati Corse test-rider, followed every phase of the Desmosedici's development process from early testing to track debut and the project's evolution. In 2007, Ducati's pilot Casey Stoner, riding a Desmosedici, obtained Ducati's first Moto GP World Championship title.