The days of the bearded warrior have largely passed. There are no knives or chains on view, let alone shotguns, and this time round, the villains of the piece are clean-shaven. But the biker wars are back, and there is blood on the roads. Lots of it.
A new generation of born-again riders, forty-something thrill-seekers dressed like the late Barry Sheene, have been blamed for a shocking 36 per cent increase in fatal accidents. Nationally, 28,000 bikers were killed or injured last year.
Egged on by celebrity motorcycle fans such as Ewan McGregor, Jeremy Irons and George Clooney, middle-aged Britons are spending £10,000 and more on machines capable of 150mph. When the weekend comes round, they dress up in expensive, one-piece racing suits and speed from the suburbs of London and Manchester for the roads of rural Britain, with frequently disastrous consequences.
From the Association of Chief Police Officers to the Royal Society for the Prevention of Accidents, the message is the same: the balding funsters are out of control.
Now the country's traditional bikers, the sort with a preference for facial hair and large "back patches" on tatty leather jackets, are revving up for battle. It is not just that they resent the spending power of the souped-up accountants and assorted middle managers. They fear the antics of the crazy gang will provoke a legal clampdown. Ministers have already voiced concern at the scale of destruction and are considering new safety measures.
The Motorcycle Action Group, Britain's largest bike club with 53,000 members, has launched a broadside at the speed merchants, condemning the "desperate situation with crazy, sports-bike riders". The MAG, which made its name campaigning against crash helmets and is still associated with a 1970s world of heavy rock and beer, has taken the step, which once would have seemed extraordinary, of writing to the Government because fellow-bikers are going too fast.
The MAG wants compulsory training for the owners of 800cc and 1,000cc machines, complaining that riders are still entitled to a licence even if they last owned a bike 30 years before. It also wants measures to tone down a bike press which glamourises speed and, the MAG president, Ian Mutch, said, has "blood on its hands".
The MAG said in its recent submission to Whitehall: "To ride a modern sports bike after only 10 to 20 hours of instruction seems to be a recipe for disaster. It seems that a majority of sports-bike riders use leather suits, EU-approved body armour etc. The eager adoption of this race-track equipment betrays an attitude that the road is simply an extension of the race track.
"Too much reliance is placed on 'protective clothing' which works well on a race-track, where riders can slide without encountering obstacles, unlike the public road. The problem is a cultural one rather than one resulting simply from the potential of modern machines."
Five million people now have motorcycle licences, some 1.5 million of them regular riders. The number of new bikers under 25 has dropped, but the number over that age has doubled. DVLA statistics show that motorcycle ownership among men of 45 is more than 20 times higher than it is among 25-year-olds. More than 21,500 men aged 45 have a motorbike licence compared with just 10,200 of 25-year-olds.
There is an easy explanation for this. It is only those with a great deal of disposable income who can afford the £7,000-plus for a performance bike, as well as the hundreds of pounds for helmets, gloves and leathers. Andy Downes, the editor of Motor Cycle News, confirms that the new breed are mostly men in their forties and fifities with well-paying jobs who, when they are not showing off on the roads, are probably playing golf. Up-market bike firms such s BMW, Harley Davidson and Yamaha have benefited from the sales boom after they redirected their marketing to the older crowd.
Some psychologists say, as you might expect, that middle-aged return to biking is an attempt to regain a sense of danger and passion. Others see the signs of a mid-life crisis.
Certainly, the power of the modern machine is awesome, a different proposition from the bikes of the 1970s. The Yamaha YZF-R1, launched this year, has 180 brake horse power and was described by one motoring reviewer as "faster than a Ferrari for the price of a Fiesta", the equivalent of a stripped-down Vauxhall Vectra with two Formula One engines.
And this, unfortunately, is much of the problem. The technology has changed so radically since the Jeremy Irons wannabes last donned leathers, that they barely know how to work the controls. As Ian Mutch puts it: "When they learned to ride, bikes were powered by the equivalent of a hairdryer."
Celebrities are no more immune than their more obviously mortal fans. Mark Knopfler, the 51-year-old front man for Dire Straits, and Liam Neeson, the film star, have both suffered dangerous bike smashes, and Arnold Schwarzenegger, 55, fractured several ribs in an accident three years ago.
Even modern braking systems take careful handling. Inexperienced riders, frightened at their new-found speed, are tempted to squeeze hard approaching bends, and they can easily find themselves flying over the handlebars. Excess speed is a problem across the country, with Paisley in Scotland, Cumbria, North Wales (where 18 bikers died last year) and Shropshire all listed as blackspots.
You get a glimpse of the mentality on specialist biker websites, where riders talk of "kick-ass roads", "straight-line sprints" and "mad-bastard cornering". Noise pollution has increased too. One of the sports bikers' favourite tricks is removing the legal silencer and replacing it with a lightweight, illegal "racing can", which produces a window-rattling nose.
On the North Yorkshire moors, with their open roads and wild, spectacular scenery, there has been a huge increase in the number of accidents. Bike deaths in the region doubled last year to 28 (out of fewer than 100 total road deaths) with 180 seriously injured.
More than a third of the bike fatalities involved the driver simply leaving the road or hitting trees and walls. The county has a policy of using mobile rather than fixed-speed cameras, and this seems to have encouraged biking magazines and websites to advertise the area as a place for reckless fun.
Pete Walker, from the Beverley branch of the MAG, and a regular on the roads around Helmsley, knows exactly who to blame. "These people have bought a cycle for nothing more than to get their rocks off. It's nothing to do with the biking lifestyle. If and when they get motorcycling banned altogether, they'll go off and do hang-gliding, abseiling or some other dangerous sport."
Things have come to a head in the North York Moors National Park, where a coalition of local celebrities is demanding police action and the imposition of a 50mph limit.
Fred Trueman, Patrick Stewart, the Star Trek actor, the former Conservative leader, William Hague and the local landowner Lord Feversham have signed an open letter attacking the sports bikers, claiming that packs of riders are racing at speeds of up to 180 miles per hour.
The campaign has been joined by a powerful Yorkshire diaspora including Sir Bernard Ingham, Lady Thatcher's former press secretary, the television gardener, Alan Titchmarsh and former cricket star Geoffrey Boycott.
Kilmeny Fane-Saunders, editor of the Radio Times Guide to Films lives on the B1527, a scenic road which runs through the western edge of the national park. It ought to be idyllic: instead it is known as the Yorkshire TT.
She is fed up with ministering to injured bikers who travel so fast she refuses to let her children cross the road. The bikers are, she says, old enough to know better. "These men, when you take their helmets off, there's grey hair, if there's any hair at all." They are the sort of people who buy Bike magazine, the news editor Rich Beach says. It pains him to admit it, but he feels that people such as Ms Fane-Saunders probably have a point.
"We do a lot of photography on those roads. We were up there recently and the amount of broken bits of motorcycle plastic and fairing was unbelievable, demonstrating the number of accidents they must have up there."
The mainstream bike magazines are another target for the MAG. Packed with pictures of race-style riding, one knee on the ground, and wheelies, they rely on adverts for powerful machines and stylish accessories. (In fairness, it should be said that the MAG's Ian Mutch edits Streetbiker magazine).
No one from the popular Performance Bike, published by Emap, was willing to comment. But Alan Dowds, deputy editor of Superbike magazine said: "We take the view that they are big enough to decide what they do with their own time, their own money and their own machines. People listen to gangsta rap albums. Does that make them go out and kill people? No. We're interested in making exciting, entertaining magazines for people to buy. And what's wrong with that?
Even Bike magazine, which attempts to place itself at the responsible end of the sports market, has offered features on "secret motorcycling playgrounds" and the best way to beat speed traps.
It faces a dilemma, of course. "We have to make the bikes look exciting," Mr Beach says. "You can't get away from the fact that these are performance machines that we're writing about, so you can't have people sitting upright. That's not going to sell bikes or magazines."
But, he adds, many of the most spectacular pictures are taken with riders going very slowly.