[1] After the early 1930s redesign of Norton's cammy models by Arthur Carroll, the CS1 became an upmarket road bike.

The frame was a new full cradle design and with a close-ratio kickstart-less gearbox, 8-inch brakes, Amal TT carburettor, Lucas Racing magneto and a 3-gallon petrol tank.

[2] The magneto was moved to the rear of the engine and the bottom end was a traditional Norton design, but in the side of the crankcase was the oil pump housing and a pair of bevel gears to drive the long shaft which ran in a tube up the side of the engine to a second pair of gears driving the overhead camshaft.

[1] Alec Bennett riding the CS1 on its first race won the Isle of Man Senior TT in 1927 and Stanley Woods set the fastest lap at 70.99 mph before retiring.

[3] In March 1931 on Pendine Sands Joe Craig and Tim Hunt achieved a best speed on the CS1 of 118 mph.