Ducati’s second-generation v-twin engine – the 900cc ‘square case’ (actual capacity 864cc) – debuted in the 860GT of 1974 and the following year was used to power the new 900SS superbike. The latter was styled like the original 750SS that had been developed from Paul Smart’s 1972 Imola winner. More than just a simple over-bore, the ‘square case’ engine incorporated a new camshaft drive arrangement, improved oil pump, cartridge-type oil filter and electronic ignition. In addition, the gearchange was moved to the left-hand side and the frame altered to provide chain adjustment at the swinging arm pivot. As had been the case with the original 750SS, desmodromic valve gear distinguished the new sports roadster from its tourer counterpart. ‘Like the tamer valve spring version of the engine in the 900GTS it is uncannily smooth, while possessing a much more dramatically punchy power output than the soft touring motor,’ reported Bike magazine in October 1977. Breathing through gaping 40mm Dell’Orto carburetors, the 900SS engine produced 70bhp at 7,500rpm, an output good enough for a top speed of 135mph. The 900SS’s competition heritage was obvious on the road: ‘While other flash Italian bikes are basically roadsters dressed up and pretending to be racers, this is the real thing,’ declared Bike.
Engine design improvements pioneered on the Darmah model were incorporated for 1978 together with a left-side gearchange, while Speedline alloy wheels were adopted part way through the year. For 1981 the 900SS underwent more extensive updating, gaining improved cylinder heads, Bosch ignition and – later on – a revised gearbox. Production ceased during 1982 after a little over 6,000 had been produced and today this classic Ducati bevel-drive twin is highly sought after.
This 1981 Ducati 900SS has been in single ownership from new until mid 2022. Noteworthy features include stainless Conti-type (Keihan) silencers; Boyer electronic ignition; and Koni shock absorbers (original Marzocchis included in the sale). The bike was recently the subject of a comprehensive re-commissioning including all fluids, spark and charging systems. The result is a bike that starts easily and rides superbly, transforming any rider in to a budding Paul Smart.
Frame no. DM860SS 090574
Engine no. 091895 DM860