|Production||1962 – 1967|
|Engine||646cc overhead valve, air-cooled parallel twin|
|Top speed||110–115 mph (177–185 km/h)|
|Power||49hp @ 6,800rpm|
|Transmission||Four-speed, chain final drive|
|Weight||198kg (434lb) (wet)|
The 650SS was a Norton motorcycle made by between 1961 and 1967 at Norton’s Bracebridge Street works in Birmingham. Developed from the Norton Dominator, the Featherbed frame was altered so that the top rails were closer together to create what became known as the 'slimline featherbed'. A 650cc twin carburettor engine was installed which was capable of 110–115 mph (177–185 km/h). The 'SS' stood for 'Sports Special' and the 600cc models were discontinued to concentrate on production of the 650SS, which quickly earned a reputation as the best of the Dommies.
Norton produced a custom touring 650 on 7 November 1960 for export only, sold in the US as the Manxman finished in polychromatic blue and a bright red seat with white piping and lots of chrome plating, and a special exhaust system only fitted to the manxman 650 twin .The Norton Manxman 650 twin had 52BHP and a top speed of over 120mph and the race machine developed by Hienzs Kragler had speeds of 150mph and won pebble beach races  on September 1961 the 650SS was developed for the home market and on 20 April 1962, Norton launched the 745cc Norton Atlas as the main export model. The model 99SS, was developed from the Norton Manxman 650 as were the 650SS and Atlas . Fitted as standard with twin Amal Monobloc carburettors with the intakes angled downwards. Twin exhausts replaced the 99SS two-into-one and the headlight nacelle was replaced with a modernised speedometer and tachometer. The 650SS was finished in a black frame with silver fuel tank and optional chrome fenders.
- Reynolds, Jim (1990). Best of British Bikes. Patrick Stephens Ltd. ISBN 1-85260-033-0.
- Brown, Roland (2006), The Ultimate History of Fast Motorcycles, Bath, UK: Parragon, pp. 214–215, ISBN 1-4054-7303-7
- Kemp, Andrew; De Cet (2004). Classic British Bikes. Mirco. Bookmart Ltd. ISBN 1-86147-136-X.
- Robert Smith (January–February 2007). "Norton 650SS". Motorcycle Classics. Retrieved 2009-08-13.
- "Norton 650SS:". Retrieved 2008-12-24.