The Raleigh Chopper, with its odd-sized wheels and tall handlebars, was the classic bike every child wanted in the '70s and '80s. Harry Potter, of Barmouth, Gwynedd, would be the envy of them all.

Back in the early 1960s, veteran US bike maker Schwinn tapped into the spirit of chopper-style motorcycles for a kids bike called the Sting-Ray. More than a decade later, the company blew up another ...