This began a long series of production of single cylinder motorcycles. They were one of the great names of the British motorcycle industry, producing machines which for decades dominated racing with highly tuned single cylinder engines under the Race Shop supremo Joe Craig. Postwar a twin cylinder model was added to the range for 1949, and this evolved into the 1970s through 500cc to 600cc to 650cc to 750cc to 850cc models with the Dominator, 650, Atlas and Commando, all highly regarded road motorcycles of their time.

Despite the racing successes, Norton was in financial difficulty, and in 1953, Norton was sold to Associated Motorcycles (AMC), who also owned the brands AJS, Matchless, Francis-Barnett and James. The Birmingham factory was closed in 1962 and production was moved to AMC's Woolwich factory in Southeast London.

With the change to AMC came a better gearbox, which was used on Norton motorcycles from 1956.

In 1956 a 600cc Dominator 99 appeared.

The 1962 500cc Manx Nortons produced 47 bhp at 6500 rpm, weighed 142 kg, and had a top speed of 209 kph. It used a dry sump 499cc single cylinder motor, with two valves operated by bevel drive, shaft driven twin overhead camshafts. The Short Stroke model (1953-1962) had bore and stroke of 86 mm x 85.6 mm. The 1946-1953 Long Stroke was 79.6 x 100 mm. Compression ratio was 11:1. It had an Amal GP carburettor, and a Lucas racing magneto.  The new price was 440 pounds.

The last Manx Nortons were sold in 1963. Even though Norton had pulled out of racing in 1954, the Manx had become the backbone of privateer racing, and even today are quite sought after.

In 1962 a Norton 650SS appeared, followed by the Norton Atlas 750 in 1963, still using featherbed frames, but the increases to the vertical twins engine capacity had caused a vibration problem. A 500cc vertical twin is smoother than a single cylinder, but if you enlarge the vertical twin's capacity, vibration increases. The 750 Norton Atlas proved too expensive, and costs were not able to be reduced. Financial problems gathered.

There was an export bike sold up until 1969 as a Norton P11, , AJS Model 33, and as a Matchless G15, which used the Norton Atlas engine in an AMC Matchless G85CS frame, with Norton wheels and front forks. This bike was reputed to vibrate less than the featherbed frame model. AMC singles were also sold with Norton badging in this era. Wankel engine
Ron Haslam on the rotary engined Norton
Enlarge
Ron Haslam on the rotary engined Norton

In the 1980s, the company went through several incarnations - mainly because, both the name was popular, and now owned by several parties: in liquidation from NVT, the global rights were split between (at least) Norton UK, Germany, America and Rest of the World.

The name was relaunched on an ambitious scale in Lichfield in 1988. The new models have succeeded on the race track - winning the Senior TT in 1992 - but they have moved rather more slowly in the commercial market. The British company had some success making the Wankel-engined Interpol 2 motorcycle for civilian and military police forces and the RAC.

This led to a civilian model in 1987 called the Classic. Subsequent Norton Wankels were water-cooled. The Commander was launched in 1988 and was followed by the Spondon-framed F1. This model was a replica of Norton's RCW588 factory racing machines which won many races including the 1992 Isle of Man TT. The F1 was succeeded by the restyled and slightly less expensive F1 sport. With high prices and possibly some customer suspicious of the Wankel engine, the factory suffered from low sales, and production ceased in the early 1990's

Models

Main article: List of Norton motorcycles

Pre War (1908 - 1939)

* Big Four (Model 1)
* 16H
* Model 18
* Model 19
* Model 20
* Model 22
* CS1
* ES2
* CJ
* Model 30
* Model 40
* Model 50 & 55
* International

War time (1937 - 1945)

* WD 16H
* WD Big Four

Post War (1945 - 1970)

* 16H
* Model 18
* Model 19
* Big Four
* Model 500T
* ES2
* International
* Manx
* Model 7
* Model 77
* Dominator 88
* Dominator 99
* 650ss
* Atlas
* Mercury
* P11
* N15C
* Jubilee
* Navigator
* Electra

Superbike era (1967 - 1978)

Norton commando models used Isolastic suspension and had 745 cc ("750") engines up to 1973 when the 828 cc ("850") engine came into use.

* Norton Commando Combat
* Commando Fastback (1967-1973) just called "Norton Commando" until 1969
* Commando Hi-rider (1971-1975) - targeted for American market
* Commando Interstate (1972-1975)
* Commando Roadster
* Commando Interpol (1970 -1976) - produced for police force use
* Commando Production Racer

Rotary period (1981 - 1992)

* Interpol 2
* Classic
* Commander
* F1
* F1 Sport
* RC588
* RCW588
* NRS588