Triumph Model H
|Manufacturer||Triumph Engineering Co Ltd|
|Also called||'The Trusty', Type H|
|Engine||499 cc air-cooled four-stroke single|
The Triumph Model H (also known as the 'Type H' and 'the Trusty') is British motorcycle made by Triumph Engineering Co Ltd in Coventry, England. A total of 57,000 Triumph Model H motorcycles were made from 1915 until production ended in 1923.
At the start of the First World War in 1914 the British Government needed effective communications with front line troops and replaced messengers on horses with despatch riders on motorcycles. A number of models were tested for suitability and the Triumph Model H was selected. With the rear wheel driven by a belt, the Model H was fitted with a 499 cc air-cooled four-stroke single-cylinder engine. It was also the first Triumph not to be fitted with pedals, so was a true motorcycle. 
Engine differences with the previous Model A included a single cam wheel with two cams replaced separate cam wheels for the inlet and exhaust valve and the new design of cylinder casting, the Model H valve head diameter was enlarged and the valves were spaced further apart. The Model H was fitted with a Sturmey-Archer three-speed countershaft gearbox operated by a hand gear change lever.
More than 30,000 Triumph Model H motorcycles had been produced by the end of the war in 1918. The Triumph Engineering Co Ltd had been using the advertising slogan Trusty Triumph since 1910 and the Model H became known as 'The Trusty' as it proved reliable in wartime conditions, despite a weakness in the front fork spring. This was prone to break on rough ground, so despatch riders would strap a leather belt around it as a precaution. When the Model H was discontinued in 1923 a total of 57,000 had been produced.