Model range
The model range was reduced for 1927. Sprinting was made illegal on
public roads in Britain and the factory dropped its OHV sprint machines. All versions of the
short-stroke 499cc side-valve engine motorcycle were also dropped (Models 3
and 5).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.
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