On March 13, 1937, Joe Petrali set a land speed record of 136.183 miles per hour at Daytona. 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, a fairing made from a cut and reshaped gas tank, and a rear tail fin assembly for aerodynamics. The tail fin had to be removed for the official attempt, though, because of the vibration it caused. This race marked the beginning of Harley-Davidson’s pursuit of land speed records. Since then, Harley-Davidson has built a variety of vehicles that have broken several different classes of land speed records.