As did the majority of their contemporaries, Norton relied on the sidevalve engine until the introduction of its first overhead-valve design in 1922, the Model 18. This proved a very successful road machine.
Competition was a rather different story, as Velocette's OHC KTT had dominated the field in the 1926 Junior TT. Norton responded with a similar overhead camshaft engine the following year.
The Walter Moore engine proved an excellent design; it retained the Model 18's 79x100mm bore and stroke and employed bevel gears and a vertical shaft to drive the cams in similar fashion to the Velocette. The new machine sported a cradle frame and, for the first time, a saddle tank. At its first outing it secured a win in the 1927 Isle of Man Senior TT with Alec Bennett at the helm.
The production version of the new CS1 duly appeared at the Motor Cycle Show later that same year and continued as Norton’s top-of-the-range sports machine until the introduction of the International.
Today this landmark sports model is one of the most sought-after of all Norton motorcycles.
Production Years: 1927-39
Power: 18.3 KW
Displacement: 490 cc
Type of engine: OHC Single
Maximum speed: 190 km/h
Weight: 145 Kg
Courtesy Motos Antigua HD