THE IMAGE WAS captured for ever in the 1969 movie Easy Rider: Peter Fonda and Dennis Hopper astride their Harley-Davidsons, the wind in their faces, the open road ahead and Steppenwolf belting out Born To Be Wild on the soundtrack. From Hell's Angels to hell-raising rock stars, the Harley was THE mode of transport — a two-wheeled, two-fingered gesture of rebellion.

This weekend, however, as 250,000 Harley-Davidson fanatics gather in Milwaukee, Wisconsin, to celebrate the classic bike's 100th anniversary, that image is no more than a fading memory. The leather may still be black, but the hair is likely to be grey — the average Harley owner is 46, eight years older than the average rider of their Japanese rivals. And far from rebelling against the values of corporate America, Harley-Davidson has joined the suits, and big-time. The progress of its stock is followed closely by American investors, its range of branded merchandise is the envy of many famous names — and it has even branched out into bridal wear.

This, you might think, would be tough to swallow for some of the bike’s more oil-stained aficionados. But you would be wrong — their loyalty is to the bike, not to the company. “I ride a Harley because I’m a Hell’s Angel,” says Sonny Barger, a former president of the Oakland chapter of the Hell’s Angels, a best-selling author and one of the club’s most visible members. “Originally we rode them because they were American-made bikes. Otherwise, there’s been absolutely no relationship between our club and the company. In fact, they would probably rather we went away.”

Contrary to popular perception, Harley-Davidson is not the No 1 motorcycle company in the United States. That distinction belongs to Honda, which holds about 25 per cent of the market, followed closely by Harley at 24 per cent. But with roughly 30 per cent of its bikes sold outside the United States, Harley-Davidson is still an all-American brand force to be reckoned with. Fifteen years ago it had waiting lists for the 80,000 motorcycles that rolled off its assembly line. Now the waiting lists have disappeared, as the company builds over 230,000 bikes a year, more than doubling its output of ten years ago. And Harley-Davidson’s stock has outperformed both Microsoft and IBM over the past five years. Wall Street observers believe that the launch next month of the biggest new product range in its history, combined with a planned expansion in Europe, will help Harley to combat the fact that its core customers are ageing. Carole Buyers, an analyst, says: “I don’t think Harley is passé. How many brands do people tattoo on their arm?”

The good times, however, haven’t always rolled at Harley. There were dark eras, like the time the business was sold to AMF (American Machine and Foundry), a company that originally manufactured railway carriages but was better known for making bowling equipment and golf carts. The AMF Harley regime lasted from October 1968 until the company was bought back by its founders in September 1981. Back then, teetering on bankruptcy, only the hardest of the hardcore bikers stuck with Harleys.

Even after the company was bought back by 13 Harley executives, it was nearly boarded up again by its bank creditors on New Year’s Eve, 1985.

Initially the company was saved by President Reagan, who slapped massive tariffs on the Japanese imports that were close to driving Harley to the wall. The new executives used the breathing space to rethink their whole strategy — aiming for corporate business and ruthlessly exploiting the power of the Harley-Davidson brand. By 1987, profitability returned and Harley-Davidson has never looked back.

WILLIAM HARLEY, 21, and 20-year-old Arthur Davidson started the Harley-Davidson Motor Company in 1903. They built their first bike in a 10ftx15ft wooden backyard shed, followed by another two that year and another three the following year. In 1905 they delivered 16 finished bikes. By 1906, the company was off and running with 50 new creations of a mode of transportation that would transform the world.

Throughout the First and Second World Wars, the Harley-Davidson motorcycle distinguished itself as an integral part of the war effort, serving in armoured divisions by scouting out ambushes, leading tank attacks, probing enemy minefields and participating in various communication and reconnaissance efforts.

In 1945, many restless GIs took to riding the same Harleys they had ridden in the service for cheap fun and adventure on the streets of America, particularly in San Bernardino, California, where the first chapter of the Hell’s Angels was formed in 1948. Then, in 1949, all hell broke loose in Hollister, California, when bike riders invaded the town. Marlon Brando (who rode a Triumph) and Lee Marvin (aboard an Indian) made a movie called The Wild One, based on the event. Ever since, Harley-Davidson has been trying to live down the outlaw image while profiting magnificently from it.

“The motorcycle used to be, for Europeans, quite a proper and an official bike used by military officers and so on,” says the writer Camille Paglia. “But it was Americans, through the Hell’s Angels, who turned the motorbike into The Hog, into a modern horse moving over the open plains.”

TOBIE GENE LEVINGSTON founded the East Bay Dragons MC, the premier African-American Harley-only motorcycle club, in 1959. “I originally rode a Harley, first because it was made in America,” he says. “It was cheap on gas, but mainly it didn’t get in the way of the family. I never had to worry about my old lady riding my motorcycle. It gave me independence. It was my own thing.”

Tobie was one of those riders who stuck with Harley through the dismal AMF days. In 1979 he bought a brand new FL Shovelhead. “At the time the Dragons were still angry at Harleys for leaking oil and all. Then someone told me that the Japanese made my front end. I jacked up my bike, and sure enough, I saw ‘Japan’ punched on the bottom of it. After that I set my bike in the garage for about eight months, even more angry But when I started riding it again, the bike rode pretty darned good. I couldn’t stay mad.”