1955 Vincent 998cc Black Prince Frame no. RD 12937B/F Engine no. F10AB/2B/11037

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Lot 57
1955 Vincent 998cc Black Prince
Frame no. RD 12937B/F Engine no. F10AB/2B/11037

US$ 120,000 - 160,000
£ 88,000 - 120,000
1955 Vincent 998cc Black Prince
Frame no. RD 12937B/F
Engine no. F10AB/2B/11037
Rear Frame no. RD 12937B/F

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', though delayed delivery of the fiberglass panels - plus continuing demand for traditionally-styled models - resulted in over half the production leaving the Stevenage factory in un-enclosed form. The enclosed Rapide and Black Shadow were known as Black Knight and Black Prince respectively. Other Series-D innovations included a new frame and rear suspension, a user-friendly center stand, plus many improvements to the peerless v-twin engine. When production ceased in December 1955, around 460 Series-D v-twins had been built, some 200 of which were enclosed models.

Supplied new via Conway Motors, this Black Prince was first registered on November 1st, 1955 and bought by the immediately preceding owner (since deceased) in January 1956. Last licensed for the road in 1957, 'RYU 283' displayed a total of only 13,000 miles on the odometer when it was offered for sale at Bonhams' Stafford auction in April 2010 (Lot 288) and purchased there by the current owner. The Vincent had been dismantled and was offered for restoration in incomplete condition, the front enclosure, exhaust system and speedometer being among the parts missing. Interestingly, it boasted twin-plug cylinder heads, a fuel tank that had been increased in capacity, and was painted blue rather than black, which might well have been the original factory colour (there is mention in Know Thy Beast of 15 machines given a blue finish).

Since acquisition the machine was been rebuilt to 'as new' condition retaining as many of the original parts as possible and keeping the bike to factory specification, including 6-volt electrics, original Armstrong suspension and Lucas ignition/electrical components, all of which were in excellent condition and clearly stamped '1955'. Most of the fastenings have been replaced with stainless steel; painted parts bead-blasted back to bare metal and then repainted with primer and 'two-pack'; and the bare aluminum parts treated to restore the factory finish. Examination revealed that the engine bottom-end was in sound condition. New parts fitted were as follows: Omega 8.0:1 pistons; valves and springs (the valve guides, etc were found to be excellent) and Amal Monobloc carburetors. Both wheels have been rebuilt with high-quality chromium-plated 19" rims, with black painted and red lined centers, shod with Dunlop T.T. 100 (K81) Tires. The forks have been overhauled with all new spindles and bushes. Missing fibreglass enclosures were sourced and fitted, together with a new Perspex screen, which was moulded using original formers. Photographs showing various stages of the rebuild are on file. Offered with its original old-style logbook and UK Swansea V5/V5C registration documents, 'RYU 283' represents a rare opportunity to acquire a freshly restored example of the ultimate expression of Philip Vincent's vision.


  • Please note, this lot is applicable to an import duty calculated at 2.5% of the import value. This duty will be invoiced to the purchaser but may be refunded if the lot is exported within certain criteria.
1955 Vincent 998cc Black Prince Frame no. RD 12937B/F Engine no. F10AB/2B/11037
1955 Vincent 998cc Black Prince Frame no. RD 12937B/F Engine no. F10AB/2B/11037
1955 Vincent 998cc Black Prince Frame no. RD 12937B/F Engine no. F10AB/2B/11037
1955 Vincent 998cc Black Prince Frame no. RD 12937B/F Engine no. F10AB/2B/11037
1955 Vincent 998cc Black Prince Frame no. RD 12937B/F Engine no. F10AB/2B/11037
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