Vincent Black Prince

Vincent Black Prince

Philip Vincent aimed high. His motorcycle would be 'a two-wheeled Bentley Continental in which the comfort of the rider rated as highly as any aspect of sheer performance.' That aspiration led to a range of remarkable machines which, even if utterly unattainable to the average classic bike enthusiast, remain intriguing to this day.

Vincent built his first bike in 1927, funded by his father. He scooped up the HRD marque and used that to sell his innovative but intimidating expensive and unusual machines when Howard R Davies' business concern failed. The well-respected racer's name was intended to 'overcome motorcyclists' natural reluctance to buy an untried new model.'

Vincent Black Prince

Collaborating with engineer Phil Irving, Vincent launched a range of litre-class V-twins which became famous for their engineering excellence and superlative high performance. The initial Series A big twin, built from 1937, was genuinely capable of sustaining 100mph and would peak at close to 110mph.

After the war came a proliferation of models which developed Vincent's theme: the Rapide which could maintain 100mph at just 3500rpm; then the Black Shadow with a 10bhp power boost to 55bhp which justly claimed to be the world's fastest production motorcycle with a 120mph-plus potential. The Series C machines were launched in 1949 complete with Girdraulic forks and a smaller, single-cylinder 500cc sibling, the Comet.

However the Vincent business was under-funded throughout its lifespan, and profit from sales did not provide significant capital for development or expansion. A new range of Series D machines was launched at the end of 1954 but they were the company's last hurrah. One of the prototypes, the 500cc Victor, didn't even get into production. Vincent stopped building motorcycles altogether shortly thereafter.

It had been Philip Vincent's belief that provision of ample weather protection combined with enclosure of engine and gearbox, would make the Vincent Series-D the ultimate 'gentleman's motorcycle'. However, delayed delivery of the glassfibre panels -- plus continuing demand for traditionally-styled models -- resulted in over half the production leaving the Stevenage factory in un-enclosed form.

The enclosed versions of the Rapide and Black Shadow were known as the Black Knight and Black Prince. In contemporary road tests the enclosed models were found to handle just as well as their un-faired counterparts, despite initial scepticism from the riders, and provided better fuel economy thanks in part to the streamlined profile.

1955 Vincent Black Prince

Other Series-D innovations included a new frame and Armstrong rear suspension; a steel tube replaced the original fabricated upper member/oil tank while the paired spring boxes gave way to a single hydraulic coil-spring/damper unit offering a generous seven inches of suspension travel. The magneto was dropped in favour of coil ignition, while the electrical system was uprated to include a 60-Watt dynamo with components from Lucas instead of Miller. In place of the integral oil reservoir there was a separate tank beneath the seat. The user-friendly hand-operated centrestand was a welcome addition, and there were many improvements to the 998cc V-twin engine including Amal Monobloc carburettors which helped both starting and fuel economy.

1955 Vincent Black Prince - Exploded view of the bodywork

The biggest change was external, however, and the new Vincents incorporated a full front mudguard and rear enclosure which hinged upwards to facilitate rear wheel removal.

Legshields with integral crash bars formed part of the sidepanels; these were carefully designed to maximise air-flow to the engine although you'd be a brave rider to test their efficiency in modern urban traffic. The half-fairing and screen housed a smaller three-inch Smiths' speedometer; the magnificent 150mph five-inch speedo was gone for good.

Although Philip Vincent felt that the Series-D was his finest design, the motorcycle-buying public greeted the innovative new models with suspicion. The appeal of the Vincent, and the Black Shadow in particular, lay in its ability to out-perform just about every other vehicle on the road, and in the early post-war years there was nothing to compare with it.

Its creator's vision of the Series-D as a luxury touring machine just did not conform to the public's perception of the Vincent as the ultimate sports motorcycle.

The firm lost money on every machine made, and when production ceased in December 1955 just 460 Series-D V-twins had been built, some 200 of which were enclosed models.

This scarcity means that although opinions about the Black Knight and Prince were mixed when they were launched - not helped by poor quality panelling on the show bikes - their values have risen steadily in the half century since their production. Clean examples of whole bikes now sell for around £35,000 to £45,000 ($65,000 in the USA March 2010).


Vincent Black Prince
Vincent Black Prince
Manufacturer Vincent Motorcycles
Production 1954 - 1955
Predecessor Vincent Black Shadow
Engine 998cc V twin
Power 55 bhp at 5,750 rpm
Suspension 'Girdraulic' oil damped (front) cantilever monoshock (rear)
Tyres Front tyre 3.50 x 19in., Rear tyre 4.0 x 18in.
Wheelbase 56.5 inches (1,440 mm)
Weight 460 pounds (210 kg) (dry)

Vincent Black Prince

The Vincent Black Prince was a British motorcycle made between 1954 and 1955 by Vincent Motorcycles. A year before the factory closed in 1955, Vincent produced the enclosed range of Vincent Black Knight and Black Prince. Phil Vincent described it as a 'two-wheeled Bentley' and the enclosed Vincents got a lot of attention at the 1955 Earls Court show. Problems with production of the glass fibre mouldings eventually led to financial difficulties and the last Black Prince left the Vincent production line on Friday, 16 December 1955.

Vincent Black Prince


Falling sales of the Series C Vincent motorcycles during 1952 and 1953 was partly attributed to dated styling, so Phil Vincent sought to update the range and development began what were to become the Series D machines. The main change was innovative full enclosure and weather protection, with glass fibre panels that included leg shields and a handlebar fairing. This was not about streamlining for speed, as the Vincent was already powerful enough for riders of the day - it was instead about the idea that the rider could travel to work in a suit rather than full motorcycle kit. Care was taken to ensure that the engines were still easily accessible for general maintenance and the rear enclosure was hinged providing access to the rear wheel and drive chain.

Vincent also tried to make it easier for the rider to get the motorcycle on to its stand by adding a huge lever on the left of the machine that could be operated from the saddle. The frame was also modified with a single tubular strut bolted to the steering head and a single damper replaced the twin rear shocks.


The Black Prince was launched at the 1954 Earls Court motorcycle show, together with the 998cc Vincent Black Knight and the 500cc Vincent Victor (which never went into production as only the prototype was ever built). There was a lot of interest but much of it was critical, and the Black Prince was termed the motorcycle you either love or hate. The Motor Cycle road tested a Black Prince and concluded that it handled as well as the Vincent Black Shadow with improved fuel consumption.


Production of the Black Prince began in the spring of 1955. Lucas components replaced the less reliable Miller electrical system and ignition was upgraded to coil and distributor. The rear enclosure, which incorporated the oil tank, was hinged allowing access to the rear wheel and final drive chain. Amal Monobloc carburettors improved starting. The centre stand was operated by a lever accessible from the saddle and the lower front mudguard stay served as an emergency front stand to facilitate the removal of the front wheel. Delay in delivery of the fibre glass components from subcontractors held back the availability of the first production bikes until spring 1955. Approximately 200 of the enclosed models were built.

Financial collapse

Increasingly affluent customers may have encouraged Vincent to go for a 'high end' luxury touring model, but at the same time high volume and very affordable small cars were flooding the market. Vincent's accountants suddenly realised that they were losing money on every Black Prince sold, so the last example of both the model and the marque left the production line on Friday, 16 December 1955.