For the 1927 season a number of refinements were adopted; the front forks were strengthened following some failures in competition, and wired-on tyres replaced the beaded edge examples previously employed. The transverse coffee pot silencer gave way to a more conventional and attractive exhaust system. The distinction between the touring Model 1 and the sporting Model 2 became more apparent as a result of the fittings employed. The Model 1 benefitted from the famous full chaincase, higher bars and valanced mudguards in contrast the Model 2 was fitted with lower handlebars, a chainguard and sporting mudguards. The 1928 season machines continued in the same form as the previous season.
Both Sunbeam and their neighbours at AJS were yet to adopt the saddle tank.
1928 Model Range
Model 1
Engine: Sunbeam single cylinder side-valve, 70 x 90 mm.
Gearbox: Sunbeam three-speed with new type enclosed kick-starter.
Model 2
Sporting version of the Model 1, with footpegs replacing the footboards, and lower handlebars.
Model 5 - The "longstroke" Sunbeam was offered in two versions during the twenties, the touring Model 5 and the sporting Model 6 and would remain a feature of the firms range from 1922 until 1940. During that time it earnt an enviable reputation for its reliability and stamina.
Engine: Sunbeam single cylinder side-valve, 77 x 105.5mm, 492cc
Gearbox: Sunbeam three-speed with new type enclosed kick-starter.
Model 6
Engine: Sunbeam single cylinder side-valve, 77 X 105.5mm, 492cc
Gearbox: Sunbeam three-speed with new type enclosed kick-starter.
Model 7
Engine: Sunbeam single cylinder side-valve, 85 X 105.5 mm. 599cc. Valve stems enclosed in Sunbeam valve covers.
Model 8
347cc OHV single-port, 70 x 90mm.
Model 9
493cc OHV single-port, 80 x 98mm.
Model 80
347cc TT OHV Two-port, 70 x 90mm, 347cc, double-hairpin valve springs.
Model 90 - Fitted with a "bullnose" tank, the OHV machine had dual exhausts from a single exhaust valve. This model won the Isle of Man Senior TT in 1928 and 1929. Approximately 100 were built between 1927 and 1930. 80x98mm, double-hairpin valve springs.
Sources: H&H Classic Auctions, factory literature, et al.
