Think of go-karting and you probably think of a bonding weekend for a management team or a birthday treat for a teenager. A proper go-kart, though, is a serious racing machine - for children of eight upwards as well as for adults. Okay, so the engine looks as if it might have come off a lawnmower, the tyres are like doughnuts and the driver sits in a tiny seat on top of a tubular frame resembling a garden gate.
But such is the power-to-weight ratio of these machines that even the ones driven by 11-year-olds will reach 70mph and accelerate from 0 to 60mph in four seconds. You can get them to go sideways round corners - and yes, people do spin off and bounce teeth-rattlingly over the kerbs.
Junior karting, which covers eight to 17-year-olds, is now recognised as the nursery for Formula One stars. Many famous big-circuit drivers - Ralf and Michael Schumacher, David Coulthard, Johnny Herbert, Nigel Mansell - started in karts, building up years of valuable experience before getting inside a full-blown racing car. And this year there is 20-year-old Jenson Button, who is racing in the Williams Formula One team. In the early Nineties he was British open kart champion for three years running, the first time aged just 11, and he only gave up karting for cars in 1998.
Perhaps not surprisingly, therefore, the karting scene is seen by Britain's young enthusiasts - about 2,500 in all - as a route to Formula One, with its global sponsors, pound;3 million contracts and life among the beautiful people of Monaco. Some of these children are undoubtedly being pushed by their parents, regardless of expense. The cost of karts, engines, professional mechanics, tyres and track time for practising can reach pound;30,000 a year.
But the karting scene also involves schools, in some ways the poor relations. Some can bolster their teams with children who have their own karts and are financed independently, but others run their school's karts on a tight budget, depending heavily on parental goodwill and support.
Such is life for the karting team of Sandbach high school for girls in Cheshire, led by maths teacher Joyce Kay with the help of a couple of colleagues and a group of enthusiastic parents.
"Club night is Wednesdays, from seven to nine," says Joyce. "It has to be at a time when the parents can come. We depend on them a lot for the maintenance of the karts, doing what we can on a shoestring. There's an awful lot of ingenuity - but of course safety is paramount."
The picture that emerges is of second-hand karts, ageing engines and tyres passed on from the privately funded individual entrants who would not deign to race twice on the same set (at pound;120 a time). Even so, it costs about pound;300 to put the school's five karts on the grid at a competition, of which there are perhaps 10 a year. Every age group in the 11-18 school is represented. There are five karts in racing trim, and the girls share them equally.
Says parent Tony Williams: "I suppose we could identify the fastest driver and the fastest kart and put them together, but we're not into that."
Towards the end of the summer term, the biggest schools meeting, the Natska (National Schools and Yuth Groups Karting Association) championship, was held at Rowrah, a track carved out of a disused quarry south of Cockermouth in Cumbria.
Twenty-five school teams turned up, with 173 competitors, plus hundreds of adults and supporters. For two days this remote site was crowded with vans, motor homes, tents and trailers.There was plenty of atmosphere, lots of laughter and, of course, the incessant sound of karts practising and racing on the kilometre-long track.
The Sandbach students were enjoying themselves. It seemed not to matter that their success rate against some of the better-equipped teams was not high. At 18, Kate Shepherd was making the most of her last season before leaving school. "I'd like to have a career in motor sport," she says, "but I have to be realistic. It would cost too much to take it to the next stage."
Few, if any, of these girls will have the opportunity to race once they have left school, but one former Sandbach pupil has turned her karting experience to good account. Kathryn Fairless, 22, was helping the school's team at the championships, having graduated the previous day from Leeds university with a degree on mechanical engineering, one of five women on a course of 120.
Kathryn raced with the Sandbach team from the age of 14 until she left school. "I was no good at netball or any other sport until I found I could do this," she says.
The experience stood her in good stead both on the degree course and in her search for a job in the car industry, and she is about to start work with an automotive consultancy firm.
"As part of my course, I designed, built and test drove a single-seat racing car. When I went for interviews they were all very interested in my experience and it definitely helped. Everyone at interview had the same qualifications as me, but I could talk about karting and the racing car."
The racing at Rowrah was fast and furious. There were occasional spins and just one somersault, from which a boy walked away unscathed. All the same, do parents worry about their children doing 70mph on the track? "Only until they see it," says Joyce Kay. "People may get a knock, but serious injuries are very rare."
This holds true even in the wider, faster world beyond schools karting. Grahame Butterworth, who runs the British Kart Industry Association, and has written books on the sport, says: "Obviously there is a great deal of emphasis on the right safety equipment - suit, boots, gloves and so on. And if anyone is racing dangerously they are pulled off the circuit. My own son had significant injuries from rugby, but raced for many years in karting without hurting himself."
The benefits are real. "It's one of the few school activities where all age groups mix," says Joyce Kay. "And at the competitions, you'll find that everyone from the various schools helps each other."
Tony Fairless, Kathryn's father, feels that it helps adult driving skills, too. "Every girl who has stayed with the team up to driving age has passed the test first time," he says. "It seems to take away the initial fear - you know straight away that you are in control."
Natska: Tony Fletcher, chairmantel: 01244 371475www.natska.freeuk.comwww.karting.co.uk is a general karting websiteAssociation of British Kart Clubs, Stoneycroft, Godson's Lane, Napton, Warwickshire CV47 8LX