Now it has come back on its own terms and with its own following: the British Human Power Club, with 350 members, 60 of them active racers, and numerous meetings every year. The racers photographed at the Herne Hill velodrome in south London may look like kiddies pretending to be Donald Campbell at the wheel of Bluebird, but in their silent, unpolluting and relatively safe way, they are pushing the outside of the envelope. "It's not a relaxation, it's an obsession," says John Kingsbury, the club's secretary, one of whose machines, the Bean, was until recently the world record holder, covering 47 miles in an hour from a standing start. "You've got limited power: a human being, who can turn out only 300 watts over an hour. And you're trying to devise a way for that human to go as fast as he possibly can."
Aerodynamics is the key: shrink the rider's profile, wrap him in fibreglass, whittle down the size by any means possible. But aerodynamics is a black art, so the scene at Herne Hill is one of dogged eavesdropping and note- taking as tips and hunches are borrowed, begged and stolen.
Leading the field in the photograph is Oscar the Egg, propelled by its creator, Jonathan Woolrich, a British Airways computer progammer. But the eventual winner was Nigel Leaper, who during the day designs Formula One racing cars for Maclaren. His vehicle is number 62, the sleek ovoid at the right with its trademark plastic bubble visor, vacuum-formed at home in an eight-foot-long oven. For him, too, the sport is far from being a therapeutic hobby. "It is not relaxing in any way, ever," he says. Not long ago he built what he calls a "rowing bike" - propelled by arms and legs together - after reading research which suggested that such a machine would go like stink. It didn't.
As you would expect from such a gathering of anoraks, Brits are best - or were until a Dutchman, Bram Moens, seized the record last year. John Kingsbury is confident, however, that our pre-eminence will be regained. Just how would be telling. Peter Popham
Photograph by Bill Coates