British motorcycle manufacturers - D

Dalesman	1969-74. Offroad.
Dalton	1920-22
Dane	1919-20
Dart	1901-06 and 1923-24
Davison	1902-08
DAW	1902-05
Day-Leeds	1912-14
Dayton	1913-60. Small engines, clip-ons and scooters after 1954. Made a small machine in 1913, and a scooter in 1955 but closed out in 1960. Dayton: also made an autocycle in 1938.
Defy-All	1921-22
De Luxe	1920-24
Dene	1903-22
Dennell	1903-08
Despatch-Rider	1915-17
Diamond	1910-38. Bought by Sunbeam in 1920.
DKR	1957-66. Scooters.
DMW	Dawson Motors, Wolverhampton. Started by W. 'Smokey' Dawson, who ran a small motorcycle business. Began making rear suspension systems in 1942, then progressed to grass-track 350 and 500cc JAP-powered machines. In 1947 they made a lightweight 125c roadster, moving to a 250cc vertical twin in 1953. Novel frame design used square-section tubing. They also made scooters, the most famous being the 250cc-Villiers powered Deemster. Made mostly trials and racing bikes until the late 1970s.
DOT	'Devoid of Trouble,' founded in 1903 (1902?) by Harry Reed. Name probably originates with his daughter Dorothy's nickname, but the slogan was used in advertising from 1923 on. Started with Peugot and Fafnir engines. Reed won the 1908 TT on one of his Peugot-powered machines, with an average speed of 38.6mph. Reed became a regular competitor after that. DOT switched to JAP engines, then later Bradshaw. In 1926, the company was in financial trouble and had to rebuild, with Reed (50) leaving. The company continued to produce and race until 1932, when the Depression hit. They stayed in business doing contract engineering work until after WW2, when they re-emerged with a strong line in 1949. They lasted until 1973, when the doors closed.
Douglas	Based on Light Motors Ltd., founded by W. J. Barter. He produced his first single-cylinder motorcycle between 1902 and 1904, then turned to a 200cc horizontal twin called the Fee (French for Fairy, which it was later named). The company failed in 1907, but was taken over by the Douglas family, which owned the nearby foundry where Light had purchased components. Douglas concentrated on flat-twin engines in its motorcycles from 1906, using an engine designed by JJ Barter. They turned the engine into a 350cc model for 1907 and sold it through 1910 with increasing success. They won several races and trials events, and became a major supplier of machines in WW1, making 70,000 bikes for the allied effort, including about 25,000 WD models. The 1915 model had a fore-and-aft flat twin engine, belt drive, and full electrical lighting. Douglas built the first disc brakes in the early 1920s. During the 1920s, Douglas had a Royal Warrant for supplying motorcycles to Prince Albert (late King George VI) and Prince Henry. Performance for Douglas machines was good, and their reputation was great, but quality and workmanship were not. Despite this, they won several races including the 1923 sidecar TT and senior TT. Even King George V acquired a Douglas machine in this period. In 1934 they produced a 494cc shaft-drive model called the Endeavour. The company made several products including airplane engines, tractors, Vespa scooters, trucks and cars. In 1935 they were in financial trouble and were taken over by BAC. They continued to make motorcycles, and in WW2 made generators and bikes. In 1948, Douglas was again in economic distress and forced to rationalize its line to a series based on a 350cc flat twin. The last model made was the advanced and novel 350cc Dragonfly, in 1955. Distinctive looks and good handling couldn't hide the low top speed (75 mph, although a sports model claimed 84mph) and poor low-rev performance. A 500cc prototype was shown in 1951, but never made. The company was purchased by Westinghouse Brake & Signal, but new owners were more interested in making Vespa scooters, and motorcycle production ceased in 1957, although they continued to import and assemble Vespas and later Gilera motorcycles.
Downer Groves
Dreadnought	1915-25
Dresda	Developed by racer David Degens, who acquired Dresda Autos in the late 1950s. He started making 'Tritons' (Triumph engines in Norton frames) which became popular race bikes. In 1965 he built a Triton, detuned for greater stability, and won the Barcelona 24-hour race on it. Later he also used Suzuki 500 twin and 750 triple, and Honda 750 quad engines.
Dunelt	Founded by Dunford and Elliott of Sheffield in 1919 with an unusual "supercharged" 499cc two-stroke single at at time when experts felt two strokes would never work above 350cc. Dunelt offered all-chain transmission in 1924. They became involved in sidecars in 1926.  Their bikes broke several records in the 1920s including the first cross-desert ride (Cairo to Siwa and back in 1924) and the Double Twelve Hour World Record at Brooklands on a Model K in 1928. But their 1929 models were not a success and by 1931 the company closed its Birmingham plant. The company continued for a few years, making three-wheelers popular as commercial vehicles, but closed in 1935. A moped with the Dunelt name was shown at the Earls Court show in 1956. Company closed in 57.
Dunkley	1913 and 1957-59 (Different company of same name that made scooters)
DUX	1904-06
Duzmo	1919-23
Dyson-Motorette	1920-22.

British motorcycle manufacturers - C

Caesar	1922-23
Cairns-Mocyc	1949-51. Clip-on.
Calcott	1910-15. Coventry.
Calthorpe	Started as a Birmingham car manufacturer by George Hands. Hands had started making 'Bard' bicycles in 1895 and gone through several company name changes until he showed his first motorcycle as a Calthorpe (a division of his Minstrel Cycle Co., later Minstrel and Rea) in 1909. He had six singles in his lineup in 1910 and added a TT model in 1911. His first twin was made in 1912. After WW1, Calthorpe emerged with a couple of JAP-powered motorcycles. A 350cc with a 'Peco' engine of Calthorpe's own design was added in 1920. The company continued to offer sturdy, low-cost machines until 1928 when a redesign and ivory paint job boosted their popularity (the "Ivory"). The company continued making motorcycles and upgrading engines right up to a 493cc model, but it was losing money. They last appeared at a trade show in 1934. Calthorpe went into liquidation in 1938. The new owners moved to Bristol in 1938, but in 1939 their factory was requisitioned for war production.  The name was briefly revived in 1947, but the company that reissued it became DMW instead in 1950.
Calvert	1899-1904. Singles and V-twins.
Camber	1920-21
Campion	1901-26. Bicycle company, also made its own motorcycles and bikes for New Gerrard..
Carfield	1919-24 (1919-27?)
Carlton	1913-40. Also the name for a Scottish firm in 1922.
Castell	1903
Caswell	1904-05
Cayenne	1912-13. Water-cooled single.
CC	1921-24. Charles Chamberlain.
CCM	Clews Competition Machines, formed by Alan Clews as Clewstrokes in 1971, chanced to CCM in 1973. Made BSA-engined (B50s and others) trials machines after buying machine tools and stock from closed BSA factory.
Ceedos	1919-29. Started with small, lightweight two-stroke bikes, later added four stoles with Blackburne and Bradshaw engines.
Centaur	1901-15
Century	1902-05
Charlton	1904-08
Chase	1902-06
Chater-Lea	Formed as Chater Lea Manufacturing Co. by William Chater Lea in London in 1900 to make frame components, it graduated to complete frames, then adding clip-on engines. In 1903 they produced their first motorcycle - without tires or saddle! By 1908 they were showing complete motorcycles and had an entry in the TT races. More than a dozen different engines were fitted into their frames to make their various models until the 1920s, when they started making their own engines. Production ceased during WW1 and started again in 1919 with big twin machines. They moved to a 350 and 545cc single in 1922. In 1925, they made their first engine entirely designed in-house, using a  fully-enclosed valve gear lubricated by a second oil pump. Name changed to Chater Lea Ltd. when founder died in 1927, business was taken over by sons  John and Bernard. Success at Brooklands in 1924 helped sales, but the bikes were quite expensive. The company's last motorcycle sales were in 1936. Their best machine was a 350cc ohc which at 100mph was the world's fastest 350cc machine. The company continued in other lines after WW2.
Chell	1939, made a few small-engined bikes.
Clarendon	1901-11
Clement-Garrard	1902-11 (1902-05?). Small clip-on Clement engines in Norton frames.
Cleveland	1911-24
Clyde	1898-1912. Water cooled engines in 1903.
Clyno	1911-24. For 20 years Clyno was one of the best-know manufacturers of motorcycles and cars. The name allegedly comes from the slogan "Car Like You've Never Owned" but in reality is a nickname for "clined."  Their early motorcycles used an innovated two-speed pulley for the belt drive, which they called inclined, hence "clined." They began showing bikes in 1909 with a 744 V-twin. Pre-war machines were designed for 'comfort and convenience.' Clyno made many machine-gun units for allied war effort 1914-18 after Winston Churchill selected the company's design for the army. During the war they developed a four-cylinder water-cooled two-speed machine for the army but the machine was shelved when the war ended. They also designed an airplane engine and a horizontal flat-twin which never saw production. They came back to civilian production slowly in 1919 with a new spring-frame 8hp V-twin, and started work on a  car. In 1922 the company reformed to concentrate on cars and by 1923 motorcycle production had ceased.
CMM	1919-21
Colonial	1911-13
Comery	1919-22
Comet	1902-07
Commander	1952-53. Innovative styling mixed with pedestrian engineering.
Condor	1907-14. Huge 810cc single.
Connaught	1910-27.  Mostly small (293 and 347cc) two-stokes. Post WW1, the bikes offered chain drive.
Consul	1916-22
Corah	1905-14
Corgi	1942-54. Folding 98cc scooters originally made for British Army. Developed from the Welbike (1942-46), it continued to be enhanced until its last model.
Corona	1902-24.
Corona-Junior	1919-23
Corydon	1904-08
Cotton	Founded by trials rider Frank Willoughby Cotton in 1914 when he applied for a patent for a frame he had designed for Levis. He began production in 1918, making his first motorcycle in 191, 1 269cc Villiers-powered bike. The company achieved several successes in races in the 1920s to mid 1930s, starting in 1923 when Stanley Woods won the first of his 10 TT victories. After WW2, the company made a weak comeback, but restructured under Elizabeth Cotton in 1953 as E. Cotton Motor Cycles. They were successful again in racing until Villiers closed and they lost their British engine source. They turned to Italian Minarelli engines for enduro and trials models, then Austrian Rotax engines in the 1970s.
Coulson	1919-24
Coventry-B&D	1923-25
Coventry-Challenge	1903-11
Coventry-Eagle	A Victorian bicycle company, they built under the trademark Royal Eagle in the 1890s. They started making a bicycle with a clip-on JAP engine around 1900, which grew to a full motorcycle by 1903. But they faltered and stopped by 1905. During WW1 they made a motorcycle using a Triumph engine, but did not return to full production of their own until 1921 when they offered two sidecar models powered by a 500cc single and a 680cc JAP V-twin. Their line expanded considerably in 1922 and continued until the Depression. Their most famous bike was the Flying Eight, a 976cc SV twin with a JAP engine and a top speed of 80 mph, made from 1923 to 1930.In 1931, their line shrank to a 500cc, three 350cc models, a 196cc two-stroke, two 147cc bikes and a 98cc autocycle. By 1933 this had further contracted to two engines a 148cc two-stroke and a 250cc two- or four-stroke. They company enjoyed a mild resurgence in the 1930s, but production closed in 1939. Bicycles continued after the war.
Coventry-Mascot	1922-24
Coventry-Motette	1899-1903
Coventry-Star	1919-21
Coventry-Victor	1919-36. Made own flat-twin engines from 1911, first complete motorcycle in 1919. Built some three-wheelers until 1938.
Crest	1923
Croft	1923-26
Crownfield	1903-04
Crypto	1902-08
Cyc-Auto	1934-56. Cycle frame with two-stroke Villiers and later Scott engine.
Cykelaid	1919-26. Small, clip-on engines manufactured by Sheppee in York
Cyclaid	Another 1950s clip-on, built by British Salmson in Lanarkshire, Scotland from 1950 to 1956.
Cyclemaster	1950 clip-on engines for bicycles, continued making engines until 1960.
Cymota	Another 1950 clip-on.

British motorcycle manufacturers - Q

Quadrant	Started by Walter and William Lloyd in 1883 to manufacture bicycles and tricycles. Started making motorcycles (autocyclette) in 1901 and motorized banking tricycles in 1902. Walter patented a unique all-in-one control lever in 1902 to raise the exhaust valve, control ignition switch, operate the throttle and the ignition advance. Started using their own engine design in 1903. Used a spray carburetor in 1904 and magneto ignition in 1907.  Company collapsed from internal disputes in 1907, and Thomas Silver left to form Silver Motors, offering the Quadrant under a different name. The original company and premises were acquired by Walter Lloyd, but after legal action, Silver was back as Quadrant Motor Company Ltd. in 1909, selling new models. After an argument with his new backers, Silver was again making motorcycles under his own name, while Quadrant made them under a new name Quadrant Cycle Co. They re-united for 1911, making several models including a massive V-twin of 1129cc and a 600cc single. After the war they made a 654 and 780cc singles, experimented with a 292c scooter, as well as developing some outdated sv and ohv models. The company tried to modernize its lineup in 1927 with a 490cc ohv, but the company closed in 1928.
Quasar	1977-82 (77-85?). Designed by Malcolm Newell, this feet-forward motorcycle had a car-type roof and body, without doors. Used a 750cc, four-cylinder engine and four-speed gear box. Later version called a Phaser, used a six-cylinder Kawasaki engine.
QUB