Desmodromic Valves (Desmo)

In a normal engine a cam opens the valve and a spring closes it. In a desmodromic system a second cam lobe and a closing rocker pull the valve shut mechanically. Because no spring can “float” at high revs, valve control stays precise.

Ducati did not invent the idea – it appeared in early 20th-century engines and in Mercedes-Benz racing cars of the 1950s – but engineer Fabio Taglioni brought it to Ducati racing bikes, and Ducati has used “Desmo” on its road bikes for decades.

Desmo valve clearances must be checked for both opening and closing rockers, so a valve service is more labour-intensive than on a spring-valve engine. Follow the interval in your service manual; modern Ducatis have much longer intervals than older models.