Dropbears

Vincent Motorcycles - A Potted History


Legend has it that Australian engineer Phil Irving placed a tracing of the Vincent 500 motor on top of a drawing of the same motor in such a manner that it formed a 47° V twin. True or not, there was an excellent reason for the chosen angle in that tooling costs for the new motor could be kept to a minimum.

Prior to WWII, Phil Vincent bought the rights to the Howard R. Davies company, (founded in 1924?), and adopted the name Vincent-HRD for his entry into the British motorcycle market. Other than the name, there was little similarity between the HRD and the new model, a J.A.P. powered single released in 1929.

The new Rapide was announced to the world in 1937. One statement in the press read:  'The idea behind the design, is the production of an exceptionally lively, high-performance mount with the same superb handling as the smaller models in the range. Not only this, but the makers have aimed at providing a 100 mph machine that is docile and does not rely on supertuning for its out-of-the-ordinary capabilities or require an ultra-high compression ratio.'

The Series A Rapide had many innovations, not least of which was the cantilever rear springing system already proven on the single-cylinder Vincent HRDs. Decades later Yamaha introduced their monoshock system - for all intents and purposes a straight copy of the Vincent system. The Rapide's other features included a stainless steel tank, twin brakes on both wheels, and a duplex primary chain connecting the powerful V twin engine to the Burman four speed gearbox.

These machines proved fast and reliable, and sold reasonably well up until the onset of war in 1939. The Series B Rapide was announced in 1945, very shortly after the war's end. The new machine had many refinements and changes including a 50° cylinder angle and internal oil galleries. This basic layout was retained for the C and D models, the last of which was built in 1955.

A factory-prepared, unfaired Black Lightning achieved 150mph at Bonneville Salt Flats in 1948, ridden by Rollie Free who had stripped to a swimsuit in search of extra speed.

In 1948 the Indian factory sent a Chief to the Vincent factory to have a Rapide engine fitted. Examples were successfully tested on both sides of the Atlantic but the machine did not go into production. A photograph of a very fine Australian restoration is available at IndianChiefMotorcycles.com.

In 1998 an Australian company, RTV, was formed to build replica Vincent motors which were inserted in a modern high-performance chassis. Very few motors were built, and the company folded the following year.

VINCENT HRD - Series A Rapide

Vincent HRD

Specifications

Make: Vincent HRD
Model: Series A Rapide
Engine: 998 cc (84 x 90 mm bore and stroke) 47° OHV V Twin
Tyres: 3 x 20 in front, 3 x 19 in rear
Frame: Brazed lug duplex tubular cradle. Cantilever rear springing
Front forks: Girder forks
Brakes: Twin drums, 7 in diameter in front and rear
Weight: 400 lb
Wheelbase: 58.5 in
Manufacturer: The Vincent-HRD Co. Ltd., Great North Road, Stevenage, Herts

VINCENT HRD - Series C Black Shadow

Specifications

Make: Vincent HRD
Model: Series C Black Shadow
Engine: 998 cc (84 x 90 mm bore and stroke) 50° OHV V Twin, 7.3:1 CR, polished conrods
Carburetor: 2 x 1.125 inch type 29 Amals
Ignition: Lucas Magneto ('55 models had Kettering ignition)
Electrics: 6v 45w dynamo
Lubrication: Dry sump, 3 US quarts
Gearbox: Burman 4 speed, triplex chain primary, wet multiplate clutch
Final Drive: 530 chain, 46/21 sprockets
Tyres: 3 x 20 in front, 3.50 x 19 in rear
Wheels Front: 1.65 x 20 in.steel rim; Rear: 1.65 x 19 in.steel rim.
Frame: Brazed lug duplex tubular cradle. Cantilever rear springing
Front forks: Vincent Girdraulic forks, 3" travel
Brakes: Twin drums, 7 in diameter in front and rear, single leading shoe 7/8" wide.
Weight: 455 lb - 206 kg [Wet - 500 lb (227kg)]
Wheelbase: 56.5 in. (1435mm)
Seat height: 32.5 in. (826mm)
Performance: 125 mph / 201 km/h - 55 bhp at 5500 rpm
Fuel Capacity 3.5 gallons / 16 litres (Other sources suggest 5 gal - 19litres)
Manufacturer: The Vincent-HRD Co. Ltd., Great North Road, Stevenage, Herts

The Black Lightning had different cams, higher strength connecting rods, larger inlet ports, polished rocker gear, steel idler gears, racing carburetors, a manual-advance magneto and was available with compression ratios between 6.8:1 and 12.5:1.

For Sale: Philip Vincent Collection

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