Engine: 50-degree OHV V-twin
Bore and Stroke: 84mm x 90mm
Power Rating: 52hp at 5,700rpm
Ignition: Lucas coil ignition, Miller dynamo
Suspension: Girdraulics front fork, hydraulic single-spring rear suspension
In 1950 Vincent reintroduced 500cc singles. The final versions of the big twin were the 1955 enclosed Series D Black Knight (Rapide equivalent) and Black Prince (Black Shadow equivalent). The luxury market was in decline, and Vincent soon ceased production.
Although unloved at its launch, the Black Prince is now one of the most valuable of all Vincent. Few, however, were imported into the USA. "The Black Prince, developed from the famous Black shadow, combines racing performance and roadholding with the most luxurious touring equipment and docility for road work." So read the sales brochure for this all-weather Series D machine. There were three "Knights," the other two being the Black Knight (based on the Rapide) and the Victor (based on the 500 Comet single). You can readily appreciate from the names alone that Philip Vincent was nothing if not a romantic.