The CS1 won the Senior TT first time out, in 1927 and even more remarkably an unknown rider Tim Hunt won the 'Amateur TT' in 1928. Open only to private riders on private machines Hunt won at a speed higher than the TT record. He used the same bike in different trim to take a Gold Medal in the 'Scottish Six Day Trial'.
Strangely further development bought little success and the push-rod Sunbeam and 4-valve Rudge proved dominant until Irishman Joe Craig reappeared on the Norton scene and helped design a new motor with Arthur Carroll for 1930.
Despite its failings the CS1 must rate as the best looking 'Vintage' bike ever, and riding it back to back with my 'Flat Tank Model 18' it is a huge step forward in both handling and comfort. The engine is mechanically stronger, with steel flywheel (replacing cast iron), bigger main shafts and bearings, and through-bolted cylinder studs.