BSA C15 The BSA C15 was a 250 cc single-cylinder ohv motorcycle manufactured by the British company BSA from September 1958 until 1967, and was BSA's first four-stroke unit-construction bike. BSA stands for Birmingham Small Arms Company and had acquired the Triumph marque in 1951 The motorbike had a 4 speed geabox and was also known as the the C15 Star, being succeeded by the  BSA B25 'Starfire' and BSA C25 'Barracuda' models in 1967.