engine was a longitudinally mounted inline vertical OHC 500 cc twin with coil ignition and wet sump lubrication which, through a dry clutch, drove a shaft drive to the rear wheel. The inline engine made this technologically feasible (flat-twin "boxer" engines on BMW motorcycles had already used shaft drives). Unlike BMW, who sensibly specified a bevel gear crown-&-pinion drive to the rear wheel, Sunbeam used worm gearing with a bronze spiral gear; by reputation the soft bronze gave rapid wear of drive components. The original S7 was produced from 1946 to 1948. In 1949, the sportier S8, with standard-sized wheels rather than the fat tyres of the S7, and BSA type front forks, was produced. The S7 design was improved and then sold as the S7 Deluxe. The original S7 was available only in black, whereas the standard colours for the S8 were "Polychromatic Grey" or black. The S7 Deluxe came in either "Mist Green" or black. If sold abroad then BSA would supply the Sunbeam in almost any colour that BSA used. Although the early S7 was not a good seller or mechanically very sound, it is the most sought after and commands a premium over the S7 Deluxe and the S8. When Sunbeam production came to an end, BSA sold the remaining stock of parts to Stewart Engineering, and this company is now the sole supplier of spares for post-war Sunbeam motorcycles. B model scooters 1959 to 1964 B1, B2 Scooters (see BSA Sunbeam). References Further reading Champ, R.C. 1983. Sunbeam S7 & S8 Super Profile. Haynes Publishing Group, Yeovil. 56 pp. Champ, R.C. 1980. The Sunbeam Motorcycle. Haynes Publishing Group, Yeovil. 205pp. Champ, R.C. 1989. The Illustrated History of Sunbeam Cycles and Motorcycles. Haynes Publishing Group, Yeovil. 112pp. Haycraft, W.C. 1954. The Book of the Sunbeam S7 and S8. Sir Isaac Pitman and Sons, Bath. vii + 120 pp. Munro, D.W. 1954. Sunbeam Motor Cycles. Motorcycle Maintenance and Repair Series. C. Arthur Pearson Ltd., London. 138 pp. External links On the Beam The Club for S7 S8 owners since 1963 Classic Glory Manufacturing companies based in Wolverhampton British brands Vehicle manufacturing companies established in 1887 Defunct cycle manufacturers of the United Kingdom Defunct motorcycle manufacturers of the United Kingdom Defunct motor vehicle manufacturers of England