MOUNTAIN SPEEDERS

IN the cool shade near the base of Mount Snow, knowledgeable mountain-bike fans crowd in along a punitive-looking, narrow dirt trail. Sissies don't descend here, and even some expert-class, cross-country riders hop off their bikes and run them downhill at full speed during a weekend of World Cup races.

"Some of these guys, after all, have to go to work on Monday," says one spectator sympathetically. Nonetheless, the crowd reserves its loudest cheers for the riders - both men and women - who plunge ahead with their feet on the pedals. Deft bike handlers are exhorted to negotiate jutting boulders and slippery tree roots on the steep incline. And when riders tumble, as they periodically do, roars of approval accompany each valiant effort to bounce up and continue on.

"When I first got into mountain biking," says Canadian Alison Sydor, a top professional rider who converted from road cycling, "people said, 'Oh, that's so dangerous; it's all kamikaze.' But I find that mountain biking is actually safer than road racing, where if one person goes down in a pack you're all going down."

Sydor is among the many cyclists these days who has answered the alluring call of the mountains, choosing to test her athleticism in beautiful natural settings, including many at ski resorts like Mount Snow that are eager to generate off-season business.

"People come to us; we don't have to beg for members by any means," says Wendy Day, communications manager of the National Off-Road Bicycle Association, which governs mountain biking in the United States and sanctions more than 1,000 events.

Mountain biking thrives in California, the Rocky Mountain region, and New England, Day says, but it is also making inroads in Texas, the Southeast, and the Midwest. "Mountain biking," she says, "is not exclusive to mountainous regions, especially not cross-country, which can be held ... wherever a trail goes."

This should be clear a year from now, when mountain biking makes its Olympic debut before millions of TV viewers. Cross-country riders will vie for medals at the Georgia International Horse Park, a site shared with equestrian riders in Conyers, Ga.

To make room on an Olympic program already bursting at the seams, other established cycling events had to be jettisoned. Bike sales dictated the move. About a quarter of 100 million bikes sold globally each year are mountain bikes, which have earned a reputation as being fun and comfortable. In the US, where a group of playful cyclists in Marin County, Calif., hatched the sport in the early to mid 1970s, the percentage is much higher.

Although mountain biking is very popular in Europe, and races are held in such major cities as Berlin and Rome, America acts as the sport's hub. Thomas Frischknecht of Switzerland, champion of the international World Cup series in 1992 and 1993, says he prefers US cross-country courses. "They are at high altitude and technical," he says, referring to the finely tuned bike-handling skills required. "European races can be too much like road races. In the US the real mountain bikers are at the front [of the field]."

What a real mountain biker is defies easy explanation, but it's safe to say they don't mind dirt and often seem to wear it proudly.

Fat, nubby tires that grip the trail often fling muddy bits of it, too. "Eat Dirt," not surprisingly, is a popular expression among mountain bikers, some of whom have crossed over from bicycle motocross (BMX), where short dirt tracks are the norm. Others have ski-racing backgrounds, which is a good fit for those who compete in mountain biking's two ski-like disciplines: the dual slalom and the downhill, where speeds can reach 60 m.p.h., and riders wear an array of head-to-toe protective gear.

Ned Overend, one of the deans of mountain-biking professionals, embodies the kind of athletic fusion found in the sport. Speaking outside the canopied trailer of his bike team, Overend says he was a track and cross-country runner during his high school and college days in California. Then he transitioned to triathlons, motorcycle racing, motocross, and bicycle road racing before ending up in mountain biking.

"This sport makes you feel like a kid," he says, adding that marathon-length cross-country races, which are his specialty, "combine the fitness of Nordic skiing with the thrill of downhill skiing."

In 1984, his first year in the sport, Overend said he was runner-up in the second US championship. This summer, at 39, he is in contention at designated races to make the '96 US Olympic squad.

Mountain biking is one of the "greenest" of all sports in terms of its natural setting. But mountain bikers have sometimes been viewed warily by other trail users, and land access is a front-burner issue. Commercially speaking, mountain biking seems to grow greener by the day. The top riders, who are pedaling billboards, can expect to make roughly $250,000, says one bike-company team manager.

A festive corporate fairgrounds at the mountain's base was one spectator attraction. A bigger draw, however, was simply the opportunity to catch a no-charge glimpse of one of the hottest new sports going.