Looking for something else (as usual) I found a copy of the Moto Guzzi Owners Club magazine, "Gambalunga". I like Guzzis, and still have two, despite my Le Mans making a determined attempt to kill me as a 60th birthday present. It probably thought it would be sparing me the indignity of age....... Regardless, inside the cover is an explanation of the title. Gambalunga is Italian for "long leg", and the 500 single was so called because of its long stroke. The motor was designed as an 84 x 90.