Douglas was a British
motorcycle
A motorcycle (motorbike, bike; uni (if one-wheeled); trike (if three-wheeled); quad (if four-wheeled)) is a lightweight private 1-to-2 passenger personal motor vehicle Steering, steered by a Motorcycle handlebar, handlebar from a saddle-style ...
manufacturer from 1907 to 1957 based in
Kingswood,
Bristol
Bristol () is a City status in the United Kingdom, cathedral city, unitary authority area and ceremonial county in South West England, the most populous city in the region. Built around the River Avon, Bristol, River Avon, it is bordered by t ...
, owned by the Douglas family, and especially known for its
horizontally opposed twin cylinder engined motorcycles and as manufacturers of
speedway
Speedway may refer to:
Racing Race tracks
*Daytona International Speedway, a race track in Daytona Beach, Florida.
*Edmonton International Speedway, also known as Speedway Park, a former motor raceway in Edmonton, Alberta.
*Indianapolis Motor Spe ...
machines. The company also built a range of cars between 1913 and 1922.
History

The brothers William and Edwin Douglas founded the Douglas Engineering Company in Bristol in 1882. Initially doing
blacksmith
A blacksmith is a metalsmith who creates objects primarily from wrought iron or steel, but sometimes from #Other metals, other metals, by forging the metal, using tools to hammer, bend, and cut (cf. tinsmith). Blacksmiths produce objects such ...
work, they progressed to
foundry
A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal into a mold, and removing the mold material after the metal has solidified as it cools. The most common metals pr ...
work.
Joseph F. Barter's Light Motors Ltd. was one of Douglas's customers.
Barter built a
single-cylinder bicycle engine between 1902 and 1904; he then developed the Fée bicycle engine system. The Fée's 200 cc
flat-twin engine
A flat-twin engine is a two-cylinder internal combustion engine with the cylinders on opposite sides of the crankshaft. The most common type of flat-twin engine is the boxer-twin engine, where both pistons move inwards and outwards at the same ti ...
[ was mounted in-line with the frame, using chain drive to a countershaft beneath (with clutch); this then used a drive belt to power the bicycle's rear wheel.][ Barter founded Light Motors Ltd. to build the Fée system.] Production began in 1905, and the Fée's name was anglicized to Fairy shortly afterward.[ In 1916 '' The Motor Cycle'' magazine claimed that the 1904 Fée was the earliest flat-twin motorcycle engine, of which there had since been many copies. Douglas made castings for Light Motors][ and took over the manufacturing rights when Light Motors went out of business in 1907.][
From 1907 a 350 cc Douglas version was on sale, similar to the Fairy with the engine in-line mounted high in the frame, but without the chain driven countershaft beneath, and with belt final drive. At the 1907 Stanley Show they attracted a lot of attention with a V4 engined motorcycle, with automatic inlet valves, and two-speed drive. The V4 did not go into production, and by the 1908 show it was only the updated in-line twin that was on show, now lighter and with a lower engine position. Around 1911 the frame was modified to make the engine still lower, and in 1912 the automatic inlet valves were replaced by mechanically operated valves.
During World War I Douglas was a major motorcycle supplier, making around 70,000 motorcycles for military use. In a 1916 review of flat-twin engines in ''The Motor Cycle'' magazine] two models of Douglas engine are listed. The 2.75 hp (350cc) with 60.5mm bore and 60mm stroke, with the valves placed side-by-side on the side of the engine. The other engine was the 4 hp (544cc) flat twin of 72mm bore and 68mm stroke. One of the significant differences with this larger engine was the oil was carried in the sump and supplied by pump to bearings and cylinders. The sump had a glass window to inspect the oil level. The valves were placed side by side above the cylinders. A third engine was the Williamson Flat Twin made by Douglas with cyclecars in mind, but produced for the Williamson Motor Company to use in its motor cycles since 1912. This was an 8 hp engine of 964cc, 85mm bore and 85mm stroke. Initially water cooled, from 1913 it was also available air-cooled.
In the 1920s Douglas built the first disc brakes, and had a Royal Warrant for the supply of motorcycles to the Princes, Albert and Henry.
Douglas motorcycles also became popular in dirt track racing
Dirt track racing is a form of motorsport held on clay or dirt surfaced banked oval racetracks. Dirt track racing started in the United States before World War I and became widespread during the 1920s and 1930s using both automobiles and motorc ...
. The 1923 RA model with disc brakes was favoured initially and this prompted Douglas to build specific dirt track models. These motorcycle designs were gradually increased in size and power with 500 cc and 600 cc engines fitted to the DT5 and DT6 Dirt Track models in the late 1920s and early 1930s. The engines had hemispherical heads and a short rigid forged crankshaft. They dominated dirt track racing for about three years. In 1929, the most successful dirt racing year, 1,200 Dirt Track motorcycles were sold.
The Endeavour, a shaft drive model, was launched in 1934. This was again a flat-twin, but for the first time Douglas fitted it across the frame instead of in-line. Like other companies of the time, Douglas was struggling, and trying to diversify into other modes of transport. In 1935 it was taken over by the Bond Aircraft and Engineering Company (BAC).
Douglas continued motorcycle production in World War II, and diversified into making engines for generators. In 1948, shortly the war, Douglas was in difficulty again, and reduced its output to the 350 cc flat twin models. The first of these, the T35, was unique in having swinging arm
A swingarm ( or swinging arm), originally known as a swing fork or pivoted fork, is a single or double sided mechanical device which attaches the rear wheel of a motorcycle to its body, allowing it to pivot vertically. The main component of the ...
rear suspension with a longitudinal torsion bar.
The 1955 350 cc Douglas Dragonfly was the last model made. Its flat-twin engine is mounted with the cylinders across the frame, like the Endeavour of 1934. However, it has chain rear drive, rather than an arguably more suitable shaft drive.
The Westinghouse Brake and Signal Company Ltd bought Douglas out and production of Douglas Motorcycles ended in 1957. Douglas continued to import Vespa
Vespa () is an Italian brand of scooters and mopeds manufactured by Piaggio. The name means wasp in Italian. The Vespa has evolved from a single model motor scooter manufactured in 1946 by Piaggio & Co. S.p.A. of Pontedera, Italy, to a ...
scooters into the UK, and later imported and assembled Gilera motorcycles.
Douglas gained significant attention in 1932–1933 when Robert Edison Fulton, Jr. became the first known man to circumnavigate the globe on a 6 hp Douglas twin fitted with automobile tyres. Fulton went on to write a book on his adventure titled "One Man Caravan".
Cyclecar
A version of Joseph Barter's horizontal twin cylinder engine of 1070 cc capacity, water cooled, was fitted to a two-seat cyclecar
A cyclecar was a type of small, lightweight and inexpensive motorized car manufactured in Europe and the United States between 1910 and the early 1920s. The purpose of cyclecars was to fill a gap in the market between the motorcycle and the c ...
in 1913. It was better equipped than the average cyclecar of the era, with shaft drive from the front-mounted engine to the rear wheels, and was sold for £200. The rear suspension was unusual, with a horizontal coil spring mounted above the differential. The front had a beam axle
A beam axle, rigid axle, or solid axle is a suspension (vehicle), dependent suspension design in which a set of wheels is connected laterally by a single beam or shaft. Beam axles were once commonly used at the rear wheels of a vehicle, but hist ...
and semi-elliptic leaf springing.
CAr production was suspended during World War I. When it resumed in 1919, the engine was enlarged to 1224 cc, and the price was increased to £400, and then to £500. This proved to be too expensive, and sales dried up after a few hundred had been made. No original cars survive, but a replica using some original parts has been made.
Motorcycle racing
Douglas had some success in motorcycle racing and trials events. Twelve Douglas motorcycles were entered in both the Junior TT and Senior TT, and another three were in the Sidecar race during the 1923 TT. This gave Douglas its first senior Isle of Man TT victories. However, Douglas had previously won the Junior TT in 1912. Tom Sheard won the 500 cc Senior TT
The Senior Tourist Trophy is a motorcycle road race that takes place during the Isle of Man TT festival, an annual event traditionally held over the last week in May and the first week in June. The Senior TT is the wiktionary:blue ribbon, blue r ...
, and Douglas won the first ever Isle of Man sidecar race with Freddie Dixon while Jim Whalley had the fastest lap in the Senior TT with a time of just under during a wet race. A Douglas also placed third in the Junior TT that year. Later in 1923 Jim Whalley won the French Grand Prix, a distance of , and another Douglas won the 1923 Durban-Johannesberg Marathon race; a remarkable achievement by Percy Flook on a 2.75 hp machine with an average for . 1923 also saw Jim Whalley win the Spanish 12-hour race and Alec Bennett won the 1923 Welsh TT race. The late twenties saw success in Austria (1929 Austrian TT was won by Rudolph Runtsch) Post war the factory had little road racing success however a Mark 3 did win an outstanding victory in the 1950 Bemsee 'Silverstone Saturday' beating all the Velocettes, Nortons and BSA Gold Stars
Influence on other manufacturers
Douglas's traditional layout of a flat-twin engine mounted with its cylinders parallel to the frame had been copied by several motorcycle manufacturers in the 1910s and 1920s. The Williamson Flat Twin, made in Coventry from 1912 to 1914, was a litre-class heavyweight motorcycle using the Douglas layout and with the engine, forks and gearbox made by Douglas. In the United States, Indian made its lightweight Model O from 1917 to 1919 and Harley-Davidson
Harley-Davidson, Inc. (H-D, or simply Harley) is an American motorcycle manufacturer headquartered in Milwaukee, Wisconsin. Founded in 1903, it is one of two major American motorcycle manufacturers to survive the Great Depression along with i ...
made its middleweight Model W from 1919 to 1923, both using the Douglas layout.
Several German manufacturers began making motorcycles with the Douglas layout when engine manufacturer BMW
Bayerische Motoren Werke AG, trading as BMW Group (commonly abbreviated to BMW (), sometimes anglicised as Bavarian Motor Works), is a German multinational manufacturer of vehicles and motorcycles headquartered in Munich, Bavaria, Germany. Th ...
made its M2B15 flat-twin proprietary engine available in 1920. The M2B15 had been developed from the reverse engineering of a Douglas motorcycle engine.
See also
* List of Douglas motorcycles
* List of car manufacturers of the United Kingdom
References
External links
Douglas motorcycles
at the Open Directory Project
London Douglas Motorcycle Club
{{British motorcycle manufacturers
Vintage vehicles
Defunct motorcycle manufacturers of the United Kingdom
Cyclecars
Scooter manufacturers
Motorcycles powered by flat engines
Defunct companies based in Bristol
1907 establishments in England
1957 disestablishments in England
British companies disestablished in 1957
British companies established in 1907