1938 VELOCETTE KSS AT THE CUTTING EDGE
The Velocette KSS debuted in 1925 as an OHC (overhead cam) 350cc air-cooled single. Being OHC placed it at the cutting edge of engine technology at a time when most machines still used side-valve designs or pushrods. The name KSS breaks down to the K for overhead cam (the German spelling is kam), and SS for Super Sport. It made 19 horsepower at 5,800 rpm. The KSS was completely redesigned for the 1935 model year, making everything after a Mark II through the 1948 model year. The 1938 KSS was the first year that electric lighting, an illuminated speedo and an electric horn became standard equipment, rather than an option.
K-SERIES OHC ENGINES EXPENSIVE TO BUILD
While Velocette was well ahead of most of its competition, engine technology-wise, with the radical OHC K-series bikes (KSS and KTT), the exotic shaft-driven bevel drive system that drove that overhead cam was complex and difficult to assemble. They required hand assembly by skilled craftsman, which slowed production to a crawl and drove costs up. The answer was the more conservative and cheap-to-build OHV M-series bikes which would become Velocette’s biggest sellers, and replace the K-bikes.