Manufacturer Ducati Successor Ducati 888 | Production 1987-1992 Class Sport bike | |
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Engine 851 cc (52 cu in), 90° V-twin, fuel injected Power 93.00 hp (67.9 kW)) @ 9,600 rpm | ||
The Ducati 851 is a 90° V-twin fully faired sport bike with liquid cooling and four valve heads. It was produced by Ducati between 1987 and 1992, when it was succeeded by the Ducati 888.
Contents
Development
The Ducati 851 was the successor to the air-cooled two-valve 900SS. Development had lagged with the continued use of two valve engines, but new investment funded the technological advance that Ducati desperately needed. After buying Ducati, Cagiva invested in the development of another V-twin, but with liquid cooling, and four-valve desmodromic heads. Massimo Bordi had designed a 4V Desmo in 1973 for his thesis at the University of Bologna, and with Cagiva in 1985, saw his updated ideas come into production as the Desmoquattro. Based on the Pantah motor, but with liquid cooling, fuel injection, and desmodromic four valve heads (with an included valve angle of 40°), the 851 made Ducati once again competitive in motorcycle racing.
The original Desmo Quattro was an experimental 748 cc 4 valve racer (seen at the Bol d'Or in 1986) and used 750 F1 Pantah crankcases. Bordi collaborated with Cosworth to develop the heads, but in the time they had, they were only able to reduce the included valve angle of the desmodromic engine to 40°, while less than 30° was possible with valve springs. Ducati stuck with the desmodromics. The subsequent 851 road bike had stronger crankcases, while the heads and valves remained the same; designed to fit above the 88 mm bore of a 748 cc version.
The 1987 – 1988 Ducati 851 Strada used the signature steel tube trellis frame, adorned with Marvic wheels, Brembo brakes and Marzocchi suspension. That first release was criticised for its handling, so the front wheel was enlarged from a 16-inch to a 17-inch (41 to 43 cm) wheel. In addition, upgraded suspension components were fitted.
In 1992 the bore was enlarged, thus creating the Ducati 888. Three 1992 Ducati superbike models were available: the 851 Strada (851 cc), the 888 SP4 (888 cc) and the 888 SP4S (888 cc).