500cc in-line twin, with all-aluminium OHC engine and car-type clutch, introduced as the S7 in 1947. The S8, introduced in 1949, features a lighter front end, with narrower tyres on 19" front and 18" rear wheels (the S7 had interchangeable 16" wheels), and a cast alloy silencer. Built by
BSA, who took over the Sunbeam label during the war, both were sold as "gentleman's touring motorcycles", with the S8 being slightly sportier, but poor performance and unorthodox design led to poor sales.

This bike is totally original apart from re-painting and some new engine parts. It was bought in Aldershot and has always lived in the Surrey-Berkshire area. The original owner still lives in Bagshot.