My father riding Excalibur in Billings at the great American Hillclimb 1981. Other then maintenance the only thing I've changed on it is the front end.
As history states, "Excalibur" is King Arthur's legendary sword.
As the story goes my grandfather first used that motor (1975) in a street frame to Hillclimb after he retired his Harley. Then my father took it over and modified a 1981kx250 frame for it when it was given the nickname. My grandfather's given name was Arthur. But most knew him as "Smokey"