An Ariel Square 4 1000cc, with a large sidecar, c1952. The bike caused a sensation when first shown at the 1931 Motorcycle show at Olympia, London. The four aircooled cylinders were set in a square formation and the ohv gear was operated by a chain-driven camshaft. The Square 4 remained in production until 1958. The company was founded by James Starley and William Hillman in 1870 to make bicycles and the first patented tensioned wire-spoke wheel. Ariel first made a powered tricycle in 1898 using a de Dion engine. They made their first motorized two-wheeler in 1901, powered by Kerry engines, selling them in 1902. The company closed in 1970.