Vincent HRD Black Shadow
The first model from Vincent was the Rapide. However, due to demand for a more "sports oriented model," the Black Shadow was introduced.
The Black Shadow traced its roots to an early-model Rapide that had been specially tuned by factory tester and racer George Brown, his brother Cliff and legendary Vincent designer Phil Irving. With relatively minor modifications, such as enlarged ports, bigger carburetors and increased compression, the test model, known as "Gunga Din" was soon making 55 bhp (41 kW), creating the specification that would become the Black Shadow.
The model became so popular that the production of the Black Shadow exceeded the production numbers of the Rapide. The inspiration for the Black Shadow was Royal Air Force pilots flying over the factory, and soldiers serving in the war. The designers created a motorcycle that could be operated and maintained by men who had been injured in combat. The clutch could be operated with just two fingers, and maintenance was made far easier than anything previously available.
The reason for its name "Black" Shadow was that the entire bike (including the engine) was painted black including baked enamel on crank-case and covers. The reason for the black on the crankcases is still disputed to this day. Some claim that the black color was for looks, others claim that it had something to do with heat transfer and dissipation. Whatever the original reason behind the painting of the engine, it was very different from anything else at a time when everything was polished and chromed.
Fewer than 1,700 Vincent Black Shadows were made, all hand-assembled.
Source: Mecum Auctions as part of the Houston auction in April, 2014