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.