1975 Ducati 864cc 900SS

• Early and rare variant
• Believed four owners from new
• Replacement frame (see text)

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.

(The 750SS continued in this new 'square case' guise, though almost all of these smaller, second-generation models were destined for the Italian market). 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 gear change 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 carburettors, 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.

This beautiful 900SS has been stored within the vendor's collection since acquisition. A frame change occurred at some point in its life, a genuine replacement frame being fitted but with the number prefix stamped on one side of the frame gusset and the serial number on the other ('DM750SS' is the correct prefix for a 1975 900SS). Not much history is known but the Ducati is believed to have had only four owners from new. The machine is offered with a file of documents to include an old V5, V5C, purchase receipt, SORN paperwork, etc. Offered with key.