Norton 1930 490cc OHC “CS1” frame # S 42286 engine # 5A 30585 A
Norton had enjoyed considerable success with their OHV racing versions of the famous Model 18 from 1922. Stanley Woods won the 1926 Senior TT, there were numerous wins in the European Grand Prix and, of course, the remarkable feat of Albert Denly averaging over 100mph for one hour at Montlhery in June 1927. 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bat’ machine (so called because the vertical shaft and its lower timing case resembles the willow of the batsman) was superseded by a new OHC machine designed by Carroll and Craig.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.
This older-restoration CS1 is a pretty rare bird: she can be seen as a transition model between the Walter Moore and Arthur Carroll designs. According to the Norton register she was built to factory racer specifications and left the factory on June 17, 1930. Receiver was Dutch Norton importer and racer Piet van Wijngaarden in Rotterdam. The CS1 was fitted with 3-stay frame # S 42286, engine # 49000, Webb forks # 850 and special NS racing gearbox # 108. From correspondence with Norton historian Simon Grigson it became clear that probably only about ten CS1 machines were fitted with this type of gearbox. The early racing history is unknown, but in 1955 the machine was registered as RU-74-84 and at that time probably a new engine number was punched in but we cannot verify whether this corresponds to the original number that is still faintly visible. In the early sixties the machine came in the possession of the well-known Dutch Norton collector Ko Konijn. He finished the restauration in 1967 and after a test run by a friend the CS1 joined the row of Nortons in Ko’s shed. After his death in 1997 a nephew became the Norton’s new guardian. She moved from the shed to the living room and there she stayed till recently, when a technical check-up was carried out. The only outing the machine had since 1967 was a short demo run at the 2014 Montlhery Revival. With the machine come quite a number of photos and other documents related to her history. We’re pretty sure she would like to be able once more to show her riding qualities to a new owner.