Sunbeam Model 14


Make Model.

Sunbeam Model 14


1933 - 38


Single cylinder, side valve


246 cc / 15.0 cu in
Bore x Stroke 59 x 90 mm
Cooling System Air cooled
Exhaust Single


Transmission 4-Speed 
Final Drive Chain 
Frame Single downtube cradle

Front Suspension

Druid forks

Rear Suspension

Rigid, spring loaded saddle

Front Brakes


Rear Brakes

Wheels Steel, laced wire spokes

Sunbeams are timeless old motorcycles and the Model 14 is a great example from the marque. Produced between 1933 and 1938 the 250cc tourer was a solid cross country motorcycle and many of them saw unofficial service during WWII throughout Britain.

Combining the Model 8’s bottom-end and 90mm-stroke crankshaft with a 59mm-bore cylinder barrel resulted in a spin-off ‘Longstroke’ 250 - the Model 14.

To reduce costs, Burman gearboxes were fitted to many models, the revamped ‘14’ included, but Sunbeam had built its reputation on superlative quality of construction and finish and was unable to drop its standards sufficiently to match its rivals for price.

John Marston Limited never produced a flat-tank 250, and it wasn’t until 1933 that they entered this particular sector of the market. They did so the easy way, by simply reducing the stroke of the existing 347cc Model 8 from 70 to 59mm, and retaining the Model 8’s rolling chassis. They called it, very aptly but confusingly for some, the 250 Longstroke, or Model 14. Complete with twin-port head, the machine looked very like a scaled-down Model 9, but it was inevitably rather over-weight.

Later in 1933 JML surprised the market with a super-sports version of the Model 14, which they called the Little 90. This really was a racer in miniature, looking very like the “big” Model 90, with a single-port head, downdraught TT carburettor, bum pad and the notorious Sunbeam positive-stop foot gearchange.

These 250cc Longstroke continued for 1934, but was replaced by a new model, the 248cc Model 16, for 1935.

By this time the writing was on the wall for the Wolverhampton concern, which as far as its ICI masters were concerned was insufficiently profitable. In 1937 new owners Associated Motor Cycles took over. Production was shifted to Plumstead where the existing range, including the Model 14, continued for a couple of years before new models were phased in.