SUNBEAM MOTORCYCLE

SUNBEAM MOTORCYCLE

SUNBEAM MOTORCYCLE

With its smooth and reliable 487cc twin- cylinder engine, good handling and a reasonable turn of speed, the S8 was the finest bike that the famous Sunbeam marque, whose history of motorcycle production stretched back to 1912, had ever built. The S8, introduced in 1949, was essentially a sportier and more reliable version of the S7, which had sold poorly following its release two years earlier.

The basic layout of the S8's engine was identical to that of the S7. Sunbeam's tandem twin unit had a 360-degree crankshaft and shaft final drive. It was also unusual in having a chain-driven single overhead camshaft, instead of the more common pushrods. Numerous changes, most of them made in a bid to cure the S7's unreliability, included extra oil capacity and redesigned pistons. The S8 was also more powerful than the original model. Its increased compression ratio and less restrictive exhiUlst pipe increased peak output slightly to a claimed 26bhp ill 5800rpm.

SUNBEAM  MOTORCYCLE

Traditional black

SUNBEAM MOTORCYCLE WITH BLACK BODY PAINT

Paint finish was black, Sunbeam's traditional choice in the days when the Wolverhampton marque was highly regarded for its top quality construction. The S8 retained the S7's twin- downtube steel frame and gained a significant handling improvement with new front forks, as well as narrower wheels and tyres. The forks were conventional BSA telescopies, in place of the original twin's unsuccessful design, which had a single spring between the legs and no hydraulic damping at all. Rear suspension was by plunger, as before, backed up by a sprung single saddle.

The S8's top speed was just over XOmph (129km/h). about 5mph (8km/h) up on the S7. but it was on [lateralion that the lighter bike had a bigger advantage. Its standing quarter-mile time of 18 seconds was several seconds quicker than the heavier S7 could manage, and the new bike generally had a much more lively feel. The S8"s revised rubber-mounting system was very effective, almost completely isolating the traditional parallel- twifi shiikes. But the positive comments could not be extended to the S8's front brake, a single- leading-shoe drum that was rated as mediocre in ontemporary tests.

SUNBEAM  MOTORCYCLE

Smooth and reliable

SUNBEAM MOTORCYCLE CLASSIC MOTORCYCLE

In most respects, though, the S8 was highly regarded, and it was certainly a more impressive machine than the S7. It was easy to start, smooth, reliable and comfortable, once leaving Motor Cycling magazine's tester feeling reasonably fresh after covering over 500 miles (805km) in 24 hours - quite an achievement in the 1950s. The S8 was also more competitively priced than its predecessor, and accounted for the majority of the 10,000 Sunbeam twin sales during the four years to 1952. But from then on development of the S8 was minimal and, after BSA and Triumph had merged in late 1956, Sunbeam production was stopped.