On March 13, 1937, Joe Petrali set the land speed record for two-wheeled vehicles on a 4-valve 61 OHV with a speed of 136.183 miles per hour on the beach at Daytona, Florida. He rode a blue 1936 EL equipped with a 61 cubic inch Knucklehead engine that was specially designed for the attempt. It featured low-slung handlebars, and a fairing made from a cut and reshaped gas tank, also a rear tail fin assembly was fitted for aerodynamics. The tail fin had to be removed for the official attempt, though, because it produced excessive vibration. Petrali won his 49th and final AMA national on August 29, 1937 at the national hillclimb in Muskegon, Michigan. In 1937, the AMA introduced a new class called Class C which featured street-legal motorcycles in an effort to make motorcycle racing less expensive for ordinary motorcyclists. Petrali saw the change as rank amateurs taking to the track on heavy street bikes rather than a track full of seasoned pros like Class A racing. But manufacturers were cutting back on racing budgets during the Great Depression, spelling the end of Class A competition and, the Class C championship became the most important championship. Petrali’s final race was at the Oakland 200 in November of 1938. It was his one and only Class C race. It was on an oiled-down one mile dirt track. Bikes were sliding everywhere and Petrali was almost hit several times. Smok’n Joe pulled off the track and hung up his leathers for good. The last great Class A champion walked away from racing.