1927
SUNBEAMS

Two versions of the 347cc side-valve model were produced: the Model 1(touring) and Model 2 (sports).

There were also two versions of the 492cc 'Longstroke' side-valve machine: the Model 5 (touring) and Model 6 (sports). The Model 5 had been introduced in 1923 as the 'Light Solo', a short-stroke engine installed in the sportier Longstroke frame - for those who wanted a sporting short-stroke without the standard Model 3 cycle parts. From 1927 the 'Model 5' name was used for the touring version of the Longstroke-engined side-valve.

The Model 7 (596cc) side-valve machine continued to be produced, aimed at side-car work.

The 493cc OHV Model 9 was produced with a single-port engine, along with its sporting version, the Model 90, with a two-port engine and separate oil tank. The 347cc OHV machine was available only in its sporting Model 80 version with a two-port engine.

Frame and cycle parts
Front forks were 'beefed up' (Robert Cordon Champ's description) to cope with higher speeds - and after failures in racing, although no failures were reported from road use. The altered forks have parallel front and rear tubes.

In 1927 wired-on wheel rims replaced beaded tyre rims.

The transverse 'coffee-pot' silencer also disappeared from the side-valves, replaced by a pipe curving across the front down-tube to the near-side of the machine.

The side-valves were differentiated by their cycle parts: the inclusion of a rear chaincase and high-level handlebars for the touring Models 1 and 5, and no rear chaincase and lower sports 'bars for the sporting Models 2 and 6.

Models 80 and 90 were given a 'bullnose' petrol tank.

Engine and gearbox
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Source:
* John Marston Ltd., 1927 'Sunbeam Motor Cycles' Catalogue.
* John Marston Ltd., Sunbeam Spare Parts List 1927.
* Robert Cordon Champ, 1980, 'The Sunbeam Motorcycle'. Haynes Publishing.
* Robert Cordon Champ, 1989, 'The Illustrated History of Sunbeam Bicycles and Motorcycles'. Haynes Publishing.