1955 Vincent 998cc Black Prince, Frame no. D12508F Engine no. F10AB/2B/10608

1955 Vincent 998cc Black Prince
Frame no. D12508F
Engine no. F10AB/2B/10608
Crankcase mating no. E74V.

• One of only some 200 enclosed models produced
• Matching numbers
• Supplied by Harper Engines Ltd
• Runs and rides 'like new'

Ever since the Series-A's arrival in 1937, the Vincent v-twin had been synonymous with design innovation, engineering excellence and superlative high performance. So in September 1955 when it was revealed that production of the Stevenage-built machines would cease, the news stunned the motorcycling world. It had been decided that the firm's future lay in more profitable lines of manufacture, and just 100 more of the fabulous v-twins would be completed. By the time its demise was announced, Vincent's final twin - the Series-D - had been in production for just six months.

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' and to reflect this change of emphasis the enclosed Rapide and Black Shadow were known as Black Knight and Black Prince respectively. In actuality, 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.

Other Series-D innovations included a new frame and 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. In place of the integral oil reservoir there was a separate tank beneath the seat. The user-friendly hand-operated centre stand was a welcome addition, and there were many improvements to the peerless v-twin engine including coil ignition for easier starting and Amal Monobloc carburettors. Sadly though, the Shadow's magnificent 5"-diameter Smiths speedometer had been replaced by a standard 3" unit.

Notwithstanding the fact that, as far as Philip Vincent was concerned, the Series-D was his finest design, the motorcycle-buying public greeted the innovative new models with suspicion, as is so often the case. 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. This was a time when the average family saloon was barely capable of reaching 70mph, and not until the advent of Jaguar's XK120 was there a production sports car that could live with the thundering v-twins from Stevenage. Its creator's vision of the Series-D as a two-wheeled Grande Routière 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 only 460 Series-D v-twins had been built, some 200 of which were enclosed models like the example offered here.

This Black Prince was imported by Gene Aucott from Harper Engines Ltd, which had acquired the defunct Vincent Engineers (Stevenage) Ltd in 1958. Harper's continued to produce Vincent spares and offered repairs and servicing, and even sold fully refurbished machines for a time during the 1960s. According to a previous owner, a VOC member for many years, the Black Prince was purchased in Cambridge, Massachusetts circa 1989, and we are advised that only some 840 miles have been covered since it was supplied 'as new' by Harpers. The windscreen has crack from age but a new-old-stock screen is included in the sale. Displaying some paintwork blemishes from age and storage, this is nevertheless a very presentable and original low-mileage example of one of Vincent's rarest models.