The first Sunbeam motorcycle - a 350cc (2¾hp) sidevalve single - left the Wolverhampton premises of John Marston Ltd, hitherto a manufacturer of finest quality enamelled goods, bicycles and - latterly - cars, in 1912. Like Marston's other products his motorcycles soon established a reputation for sound construction and exemplary finish. The marque quickly established a reputation for sporting prowess, achieving second place in the 1914 Isle of Man Senior TT and winning the 1920 race. Overhead-valve engines were introduced in the mid-1920s but early successes were achieved with sidevalve-engined machines, most notably the 492cc (3½hp) 'Longstroke', which secured a debut win at the 1921 French Grand Prix ridden by Alec Bennett. In road-going form this remarkable engine remained in production right up until WW2.

A version of it powered the new-for-1931 Model 6 Lion. Introduced in the summer of 1930, the revamped Lion replaced the old Model 6 and featured the innovations - for Sunbeam - of a chromium-plated fuel tank and Webb-pattern girder forks. A 598cc Model 7 Lion joined the range the following year and the two sidevalve workhorses continued in production - surviving Sunbeam's 1937 sale to AMC, relocation of production to Plumstead and the axing of the rest of the traditional models - until the outbreak of WW2.

Manufactured in September 1932, this Model 6 Lion Longstroke was acquired by the current vendor in 2007 and restored in 2008. However, it should be noted that the dynamo is not connected and we are advised that the machine has yet to be commissioned for the road following the rebuild. Offered with Swansea V5C registration document.