Sunbeam 1917 3 ½ HP sidevalve single frame#4828 engine# 112/4924 CS
The Wolverhampton based firm of John Marston Ltd. earned fame for their superb bicycles at the end of the 19th and beginning of the 20th century.
In 1912 their first motorcycle was presented. It was equipped with a 2 ¾ hp model designed by Harry Stevens, one of the talented family of Stevenses later to found their own company not far from Sunbeamland.
In general motorcycle design and manufacture was done according to the standards set for the Sunbeam bicycles: elegance, silence, reliability and impeccable finish were the key words.
At the end of 1913 a 3 ½ HP model ( 85x88mm) was launched, a model that would make the Sunbeam name world famous.
Nickel plating on Sunbeams was kept to a minimum, almost all parts were enameled black.
The enamel was of outstanding quality, as witnessed by many vintage Sunbeams still having their factory finish… The whole machine followed John Marston’s dictum of the best possible quality allied to the best possible specification.
Some of these outstanding feaures are the aluminium alloy primary chaincase and the “ little oil bath” enclosed rear chain.
During the war years civilian production was limited; a chain cum belt model was supplied to the French army and the standard 3 ½ HP was supplied to the army in the usual matt khaki paint. Hundreds of V-twin outfits were sold to the Russian allies.
Motorcycle production was on a relatively small scale because John Marston was engaged in the production of vital vehicle and aircraft radiators.
In 1917 only a few hundred machines were made.