Marston produced a striking catalogue for 1914, rather than the simple brochures of the two previous years. It shows winged victory crowning the 2¼ h.p. machine following its success in winning the premier solo award in the 1913 Auto-Cycle Union Six Days' Reliability Trial. A T.T. version of the 3½ horsepower machine was added to the three model range from the previous year. Later in the year they made their first entry in the T.T. races, taking a creditable second place in the Senior with H.R.Davies in the saddle. Davies went on to become one of the most enduring names in motorcycling history. the 2 ¾ h.p. and the 1914 3 ½ h.p. models being successful in long-distance trials and road-racing from the start, the '3 ½' obtaining a solid second place, ridden by H.R.Davies, in the 1914 Senior TT. At this time, a young and talented engineer and rider, George Dance, joined the company.
The range for 1914 consisted of:
2¾ h.p. (349cc) model
6 h.p. (770cc) JAP v-twin model
3½ h.p. (499cc) Standard model
3½ h.p. (499cc) T.T. model
The 2¾ h.p. model was dropped from the range, and the 3½ h.p. model was redesigned and produced in 'Standard' and TT versions. The former model was also produced for the War Department as a 'General Service' model (engines stamped 'GS').
Marstons issued both pre-season and mid-season catalogues. The mid-season catalogue introduced a re-engined v-twin model, an AKD (Abingdon King Dick) engine of 798cc replacing the JAP engine from the previous year. War production was making JAP engines hard to come by.
The most notable visual change was the new parallel-sided magneto chain drive cover for the single cylinder machines.
The range for 1915 consisted of:
3½ h.p. Standard model / War Department GS (General Service) model
3½ h.p. TT model
6 h.p. (770cc) JAP v-twin model
6 h.p. (798cc) AKD v-twin model
Production of the 1915 range continued for most of the year until civilian production was suspended by the British Government's Ministry of Munitions on the 3 November 1916 The the 3½ h.p. Standard model continued to be produced for the War Department as a 'General Service' model (engines stamped 'GS'). The 1916 catalogue showed it used for side-car outfits. Both 6 h.p. and 8 h.p. v-twin machines were listed in the year's catalogue. The former presumably the AKD (Abingdon King Dick) engined machine from the previous year. The 8 h.p. model involved fitting a Swiss MAG engine of 996cc (82x94mm) into the frame of the 6 h.p. machine. These machines were supplied to various Allied armies as ambulance and armoured (machine gun) outfits. A belt-driven Sunbeam (the only one ever manufactured) was built to French Government specification. Its 5 h.p. rating was the result of a modified 3½ h.p. engine to give a capacity of 550cc (85x96mm) - based on George Dance's pre-war experimentations. The gearbox was also unconventional for Sunbeam, having both primary and final drives together on the nearside of the machine. Robert Cordon Champ refers to a production run of less than 1,000 machines.
The range for 1916 consisted of:
3½ h.p. Standard model / War Department GS (General Service) model
3½ h.p. TT model - no photo
6 h.p. (798cc) AKD v-twin model - no photo
8 h.p. (996cc) MAG v-twin model
4 h.p. (550cc) French Military model
Brendan Kelly has kindly provided details of his restored 1916 General Service model.
Peter Ashen recounts the restoration of his 'White Russian' MAG-engined Sunbeam in the newsletter of the North Birmingham Section of the Vintage Motor Cycle Club. The article is in two parts.
http://www.vmcc-nbs.co.uk/extras/newsletter%20Mar%202007.pdf
http://www.vmcc-nbs.co.uk/extras/newsletter%20May%202007.pdf
On the 3 November 1916 civilian production was suspended by the British Government's Ministry of Munitions. John Marston Ltd issued an over-stamped 1916 catalogue for 1917. 1916 machines were available from stock. As a result of the Russian Government's decision in 1916 to mechanise its army, Marston's was contracted by the Ministry of Munitions to supply 850 v-twin 8 h.p. side-car machines and 500 solo machines. Despite the Tsar being deposed in April 1917 the contract continued until the summer of 1917.
The 3½ h.p. Sunbeam solo machine was considered too low a capacity for the Russian Government. Their specification resulted in Marston producing a v-twin solo machine using a 5 h.p. (654cc) JAP engine installed in a modified 3½ h.p. frame.
Similarly, the 8 h.p. MAG-engined model from 1916 was modified to take an 8 h.p. JAP engine of 996cc (85.5x85mm). A slightly altered frame, increasing the wheel-base from 60 inches to 61.5 inches, and larger 28 inch wheels provided the space and ground clearance for the JAP-engine.
The belt-driven French military model which had commenced production the previous year continued.
The range for 1917 consisted of:
3½ h.p. Standard model / War Department GS (General Service) model
8 h.p. (996cc) JAP v-twin model
5 h.p. (554cc) JAP v-twin Russian Military solo model
4 h.p. (550cc) French Military model
In 1918, as for 1917, John Marston Ltd issued an over-stamped 1916 catalogue, with machines available from stock. Military production consisted of the 3½ h.p. General Service model and an 8 h.p. JAP-engined v-twin model.
The range for 1918 consisted of:
3½ h.p. War Department GS (General Service) model
8 h.p. (996cc) JAP V-twin model
Source: sunbeamsidevalve.com
