Norton 1935 “CS1” 490cc OHC frame # 5 58668 engine # CS62297
Norton had enjoyed considerable success with their OHV racing versions of the famous Model 18 from 1922. The opposition were however developing overhead camshaft engines and Norton’s Walter Moore responded with the CS1 (Cam Shaft 1), which shared the bore and stroke dimensions of its OHV brother at 79mm x 100mm. A 350 engine was also made, being designated the CJ (Camshaft Junior). The bottom half of the engine was the same as the dry sump OHV engine, but two pairs of bevel gears and a vertical shaft drove the camshaft which was located in a tidy cam box mounted on the four cylinder head bolts. The frame was also new and for the first time Norton abandoned the ‘Flat Tank’ in favour of a ‘saddle’ type. Norton fielded a strong entry for the 1927 Senior TT and they dominated the race with Alec Bennett winning after Stanley Woods had lost the lead near the end of the race with non-functioning clutch. The public were able to purchase the production version in November of that year, following its sensational debut at the Motorcycle Show at Earls Court. Produced from 1927 to 1930, the Walter Moore ‘Cricket Bat’ machine (so called because the vertical shaft and its lower timing case resembles the willow of the batsman) was superseded by a new OHC machine designed by Carroll and Craig. The “CS1” model name was carried on though and it became a sports touring brother of the famous Inter model that was introduced in 1932. The International differed in a number of respects, notably an inclined offset inlet port, TT carburettor, hairpin valve springs, sports mudguards and different gear ratios.
In the 12-model 1936 range the “CS 1” was, after the two Inter models, the third most expensive machine.
According to Norton factory records the machine we offer was built in September 1935. Most models constructed after August in any year were coded for the following year, so this CS1 was assembled as a 1936 model. The rubber-mounted handlebars were a new feature for that year. The machine is fitted with the panel tank that could be ordered as an extra. The panel holds a 120mph Smiths speedometer, amp gauge and lighting switch. There’s a centre stand and a rear stand on board and a Lucas electric lighting system. This road-registered CS1 is an older restoration in good condition.