A much-revised range of motorcycles was introduced, along with model
numbers, which were to to be used by Sunbeam for the remainder of their
production at Wolverhampton.
The new 347cc side-valve motorcycle was
advertised in touring and sports versions, whilst the 'square'-stroke 499cc
engine was reduced to two models - the Standard and the 'Light Solo' versions.
The latter model continued to use the Longstroke's cycle parts.
A new 'Model 4 Deluxe' (599cc) motorcycle was added to the range. It took its
engine from the existing 4½ h.p. model,
fitted into the 3½ h.p. Standard model's frame. The 1923 4½
h.p. model itself continued in production as the Model 7. Aimed at side-car
work it was to be the last flat tank motorcycle to remain in production -
still available in 1932 long after 'saddle tank' motorcycles had emerged.
Over-head valve (OHV) machines were introduced in 350cc and 500cc capacities. Both a
'parallel' and a 'sprint' framed version were available for each. The
350cc models were designated Models 8 and 10 respectively; and the 500cc
models designated Models 9 and 11 respectively.
The 8hp v-twin, JAP-engined motorcycle was no longer listed.
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Engine and gearbox
The 4½ hp model gained a four-speed constant mesh 'rack and pinion' gearbox; an up-grade
intended for the 8 h.p. v-twin.
* Robert Cordon Champ, 1980, 'The Sunbeam Motorcycle'. Haynes Publishing.
* Robert Cordon Champ, 1989, 'The Illustrated History of Sunbeam
Bicycles and Motorcycles'. Haynes Publishing.