The Desmodue 1100 Evoluzione
The lightweight, L-Twin stands at the pinnacle of more than three decades of Desmo air-cooled development and its torquey power delivery has excited riders worldwide. Its latest evolution combined with the Monster’s airbox capacity and new exhaust configuration marks a milestone for Ducati’s two-valve engine as the first to reach 100 hp. The 1100cc Desmodue Evoluzione power unit continues to use a bore and stroke of 98 x 71.5mm, but its long list of refinements have boosted its power to 100 hp (73.5 kW) at 7500 rpm with 76 lb-ft (10.5 kgm) of torque at 6000 rpm giving it smooth power delivery from city-like low rpm to exhilarating open road performance at redline. The 1100's crankcases are vacuum cast using the same Vacural® technology employed for the Superbike engines, a process that achieves significant weight saving and ensures consistent wall thickness and increased strength.
But the crankcases are only one part of the evolution. In addition to the new magnesium alternator cover, the 1100 now has a lighter crankshaft assembly, using an 848-style Superbike flywheel and the search for further weight reduction even went as far as using lightweight rare-earth magnets for the generator assembly. Power gains have come not only from the new lightweight crankshaft assembly, but also from an evolution of the top-end of the Desmodue power unit. The cylinder head, which now has improved lubrication and cooling performance, also has a redesigned inlet port shape for optimum flow and a modified combustion chamber shape for improved burn efficiency. This improved efficiency is the result of increasing the compression ratio from 10.7 to 11.3:1 and the change to a single spark per cylinder ignition now managed by high-speed Siemens electronics. Ensuring a sufficient feed and maximum volumetric efficiency to the higher compression set-up is a 5% increase in inlet valve lift and 4% for the exhaust, safely enabled by Ducati's unique Desmodromic system, where valve closure is activated mechanically. At high rpm it would be almost impossible for the valves to follow the steep closure profiles of the cam lobes if they were relying upon normal valve springs. With the Desmo system, the valves are closed mechanically with the same accuracy as they are opened, enabling steep cam profiles and radical cam timings. This system is used on every single Ducati power unit including the race-winning Superbike and Desmosedici MotoGP engines.
The Monster 1100EVO uses a new style of slipper clutch specially designed for the “wet” clutches of larger capacity engines. It features an oil bath system with ‘slipper’ function and super-light feel at the lever. Its design uses a progressive self-servo mechanism that presses the plates together when under drive from the engine, enabling the reduction of the clutch spring rates. This results in a much lighter clutch lever at the handlebar, ideal in traffic or long journeys. When the drive force is reversed (over-run), the same mechanism reduces the pressure on the clutch plates, enabling them to provide a race-like ‘slipper’ action which reduces the destabilizing effect of the rear-end under aggressive down-shifting and provides a much smoother feeling when closing the throttle or down-shifting under normal riding conditions. An additional cush-drive damper mechanism also smoothes the repeated transition from drive to over-run during stopstart traffic. The clutch and alternator covers are finished in a sophisticated looking carbon grey.
With more experience in twin-cylinder high performance engines than any other manufacturer, the air cooled L-Twin remains central to Ducati's philosophy of motorcycling. This experience, plus constant investment in quality by design, advanced materials and engineering techniques has enabled a distance between service intervals of 7,500 miles (12,000 km) making Ducati ownership even more enjoyable.