in Dieppe In 1904, the first motor car, a 10 hp four-cylinder model, was announced. Some, or all, of the engines for these early cars were made by
Johnson, Hurley and Martin Ltd at their Alpha Works in Coventry until about 1909 (there was a dispute in 1913 over ownership of the engine block casting patterns). In an article about assembling cars from components, it was stated that the 16-20 Calthorpe, launched in 1907, had an Alpha engine. The 16-20 model was launched in summer of 1907, and appeared at the Olympics motor show, where it was described as having a 4-cylinder engine of 93mm bore and 104mm stroke (so 2825cc), with a Hele-Shaw clutch and transmission by live axle. White metal bearings are used in the engine, but ball bearings are to be found in the gearbox and back axle. There is a fifth transverse spring to aid in keeping the body steady when travelling over rough roads. This particular model did very well in reliability trials and other events in 1907 and 1908. At the Olympia show in 1908 it was announced that for the forthcoming season the 16/20 would have an increased stroke from 105mm to 120mm, this appears to coincide with the Calthorpe moving away from the Alpha engines, to another supplier. Calthorpe briefly made some larger types, but it was in the light car field that they specialised, using proprietary
White and Poppe engines. The cars were successfully raced in
France in the Coupe de l'Auto series. A small car was announced in 1913 for the 1914 season with the 10 hp Minor, which proved to be a real large car in miniature, with a 3-speed gearbox and shaft drive. After the war the large cars were dropped, but the Minor re-appeared with a slightly larger engine of 1261 cc. In 1920 a Mr J Mathews was in charge of production, and a target of making 50 cars a week was set. The cars continued to have excellent coachwork made by the Calthorpe subsidiary company of
Mulliners (acquired in 1917), who had an adjacent factory. Sporting activity continued with
Woolf Barnato, amongst others, racing at
Brooklands. George Hands briefly left the company in 1922 to set up his own Hands make of cars in the Calthorpe motorcycle factory in Barn Street, Birmingham but returned in 1924. Whilst away he developed the six-cylinder overhead-camshaft engine that was fitted for a short time to the 12/20. The Hands cars seem to have used
Dorman engines. The days of the high-quality light car were coming to an end by the late 1920s, and sales of the fairly expensive Calthorpe were declining. A receiver had to be appointed in 1924, and the Bordesley Green factory closed, but very limited production kept going for a while. A final fling with the 1925 15/45 six-cylinder 2-litre car was really too late, and sales of the remaining stocks of cars had virtually ceased by 1928. About 5,000 cars were made in the post-war period; pre-war production is uncertain. Fewer than ten cars are thought to have survived. ==Car models==