Introduced in 1948 as a sportier version of the Vincent Rapide, the Black Shadow became a legend almost instantaneously. The most serious characteristic of the hand-built Black Shadow was its speed, and it was advertised as: "The World's Fastest Standard Motorcycle. This is a Fact Not a Slogan."
The Rapide on which the Black Shadow was based already had a fine reputation and was an undeniably stellar performer in its own right, so it was a good starting point for the designers at Vincent HRD. They shortened the wheelbase, used a 50 degree 1.0-liter V-twin that made extensive use of aluminum, used a fairly low 6.8:1 compression ratio (fuel in postwar England was of poor quality), featured a beefier chain and was couple to a four-speed gearbox.
Other elements that added to performance included the use of the powerful 1.0-liter V-twin engine as a stressed member of the frame, the extensive utilization of aluminum alloy (including on the mud guards) and the application of four separate brake drums for incredible stopping power, at least by the standards of the day. The Black Shadow also featured a dual seat with a tool tray beneath it.
The Black Shadow weighed less than 500 pounds even with full equipment (453, to be exact), which was an incredible achievement for such a large and powerful motorcycle. It was still heavier than the designers had originally intended, but it tipped the scales at around 100 lb less than many of its contemporaries. Fuel economy, meanwhile, was anywhere from 50 to 60 mpg. The Black Shadow also utilized what Vincent called a “Girdraulic” fork, which was basically a girder fork with 3” of travel that used a hydraulic damper instead of a central spring, meaning it was sort of a hybrid between a girder fork and a full telescopic like that found on many other motorcycles.
The Series B Black Shadow gained increased compression as well as a few other engine tweaks to bring power up from 45 to 56. Other changes included cast iron brake drums and a 150 mph speedometer. 1948 Also saw Vincent introduce the incredible “Black Lightning” with 85 hp. It was a stripped down race-oriented version with larger Amal carburetors, lightened components and hotter cam. 20 of these sub-400-lb rockets were built.
Aside from being the iconic British bike of the postwar period, the Black Shadow is also considered the world's first superbike. The impressive top speed of 125 mph for the production version was not matched by any production motorcycle until long after its production ended. In fact, until the 1973 introduction of the Kawasaki Z1, Vincent's claim as the fastest thing on two wheels still held true. The Stevenage manufacturer stopped building motorcycles in 1955 due to insurmountable financial woes and turned to general engineering instead, but the Black Shadow's reputation has assured the company's and especially the Black Shadow’s place among the all-time greats. As such, the Vincent Black Shadow is highly collectible and has been for some time, so finding any example for sale is significant.