Motorcycle design adapts to highways

Many years ago I was asked to write a piece about the classic succession of Harley-Davidson’s big twin engine designs – each of which has a venerated name. Knucklehead, Shovelhead, Panhead and Evo. Because so much of my practical experience had come from trackside servitude to two-stroke race bikes, I drove to the shop of a man whose profession then was providing machine shop services to owners of ‘iron Harleys’ – those with the earlier cast-iron heads