NORTON MOTORCYCLE'S

NORTON MOTORCYCLES

NORTON MOTORCYCLE

Norton's 650SS was built in much smaller numbers than the Triumph Bonneville, the most popular variation on the 650cc vertical twin theme favoured by the British manufacturers in the 1960s. But the disparity in production levels was not a fair reflection on the worth of the 650SS, whose speed, handling and refinement made it one of the finest machines on the road for much of the decade.

When the 650SS was launched in 1962, it was the latest example of the Bert Hopwood-designed Dominator twin line that had begun with the Model 7 in 1949. In 1956 the motor had been enlarged to 597cc to create the Dominator 99; and in 1961 Norton had produced a long-stroke 646cc engine to power the Manxman 650 export model. By this time there were also SS (Sports Special) versions of the 500 and 600cc bikes, with twin carburettors and higher compression. 

 

NORTON  MOTORCYCLES

Impressive powerplant

Combining the Sports Special specification with the larger capacity gave an impressive new powerplant, which also incorporated modifications including larger big-end bearings and a heavier flywheel. The 650SS also featured a new downdraft cylinder head, developed from engineer Doug Hele's Domiracer competition machine. Peak output was 49bhp at 6800rpm.

The new engine was held in a familiar chassis combining Norton's Featherbed twin-cradle frame and Roadholder front forks. At 4001b (181kg) dry the 650SS weighed barely more than the smaller models, and had a racy look enhanced by paintwork in Norton's traditional silver. Options included chromed mudguards, and the addition of a rev-counter alongside the Smiths speedometer.

That speedo was put to good use, because the 650SS was capable of almost 120mph (193km/h). It waalso pleasantly flexible and impressively economical (though the downdraft carburettor arrangement caused a few flooding problems), as well as smooth by parallel twin standards.

Given Norton motocycles reputation for handling, it was no surprise that the 650SS excelled in the bends. This was a real sports machine, with a firm ride and a thin seat. Its steering and stability were outstanding, as was the efficiency of its drum brakes. Like the other SS models, the 650 was fitted with an Avon Grand Prix rear tyre, which also helped justify Norton's advertising boast of it being 'the world's best road holder'.

Predictably the model was given enthusiastic reviews. Motor Cycling praised the 'sporting top end without the bad manners associated with such urge at low speeds'. Rival magazine The MotorCycle speed-tested the 650SS at 118mph (190km/h), and applauded a bike whose 'quietness, smoothness and lack of fuss make speed deceptive; a machine with such superb handling and braking as to make nearly two miles a minute as safe as a stroll in the garden'.

The Norton impressed in production endurance races, taking Phil Read and Brian Setchell to wins in the Thruxton 500- mile and Silverstone 1000-mile (1609km) events w?thin months of its launch. A 650SS also won the Thruxton race the following two years, and was voted' Motor cycle News machine of the year in 1962 and '63.

NORTON MOTORCYCLE

Despite that, the 650SS never came close to matching the Bonneville in popularity, partly because it was more than 10 per cent more expensive, and partly because troubled Norton produced relatively few bikes at that time.

The final batch of machines built at Norton's famous factory in Bracebridge Street, Birmingham, were 650SS models in police specification, destined for Queensland in Australia. The model survived Norton's acquisition by Associated MotorCycles in 1963, and the move to Woolwich in south London. It continued in production, with few changes, until 1968.