Vincent History
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.
Vincent Black Prince
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.
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
Source:Realclassic Uk
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