An experimental over-head camshaft (OHC) machine was entered for the year's Senior and Side-car T.T. races but performed badly and was not developed. A small batch of the 500cc OHC engines was produced along with a single 600cc version for the T.T and an experimental 350cc version for evaluation. The OHC engine was not put into production.

Cycle parts
A front drum brake, introduced for OHV machines the previous year, became standard across the range, even on the Model 7.

Engine and gearbox
[text to be added].

Sources:
* Robert Cordon Champ, 1980, 'The Sunbeam Motorcycle'. Haynes Publishing.
* Robert Cordon Champ, 1989, 'The Illustrated History of Sunbeam Bicycles and Motorcycles'. Haynes Publishing.