The ES2 proved to be an immensely popular mount for the serious motorcyclist, and good examples are always in demand.
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The ES2 made its debut at the 1927 Olympia Show and was generally produced to a more up to date specification than the Model 18. It featured the overhead valve engine as fitted to the Model 18, but with the magneto resited behind the cylinder, the drive coming off the primary chain.
The frame was of a new full cradle design which was also used on the brand new overhead camshaft CS1 machine. The petrol tank was of the saddle type then coming into vogue; by 1929, all the old flat tanks had been eliminated on Nortons. For 1931, there was a redesign of the right side crankcase to enable the magneto drive to be taken off the inlet camshaft. This was standardised on all other OHV and SV machines at the same time. A second drive side main bearing was added in 1934 along with valve guide oil pipes. The ES2 had its valve gear enclosed in 1938. There was an option of plunger rear suspension in 1939 as well as the International petrol tank.
During the year, with war clouds looming, all Norton production was turned over to side valve machines for the military. Production was resumed after the war with the plunger frame and telescopic forks now standard; then the engine internals received a lot of attention in 1948, with a number of modifications being incorporated. The laid down gearbox was fitted from 1950 and in 1951 a larger 3.5 gallon petrol tank was put onto the ES2 as well as other machines in the range. In 1952, the frame became a swinging arm type with Girling rear dampers; the 8" front brake was introduced in 1954; many changes occurred in 1957, most notably a new cylinder head with integral pushrod tunnels, and then in 1959 a change to alternator and coil ignition. In the same year the frame was replaced by the Wideline Featherbed, followed by the Slimline in 1961 until production ceased in 1963.
The letters 'ES' are thought to represent 'enclosed springs'.