''Great Things Are Done When Men And Mountains Meet.'' -- William Blake -- The Dirt On Mountain Biking

SOMEWHERE ON THE SOUTH SIDE OF GROUSE MOUNTAIN, VANCOUVER, B.C. - I am riding a narrow, snaky, pine needle-strewn trail when a gnarly cedar root rises up from the path ahead of me.

An image from hiking in the Olympic rain forest a week earlier flashes through my mind. Trail signs - illustrated by a foot going "ouch!" - cautioned against walking on tree roots. It's like stepping with your heavy boot on someone's bare foot, they said.

If a boot hurts, a knobby mountain-bike tire has got to smart. I ponder my dilemma. Jumping gnarly roots is one of the sheer joys of mountain biking. You lean back in the saddle, pull up on the handlebars, wheelie over the root, rise out of the saddle and move your torso forward, crouch and yank the rear wheel upward by pulling up on the pedals, and whee! You're over the root.

It's called a bunny hop. If I'm more lucky than good, I can clear the root and sail on down the trail. I will be able to face my environmentalist friends, my hiking comrades and my immediate loved ones with a clear conscience.

All goes well with the first half of the maneuver. Front wheel up and over. Out of the saddle. Up on the pedals.

WHOA!

Our sinewy friend has disguised a four-foot dropoff on the other side of the tree trunk. I'm not ready for this. Already my upper body is too far forward, propelling the bike into a front-wheel stand. To make matters worse, I panic, instinctively grabbing the brakes.

Endo! Stacker! Faceplant!

Mother Nature has her revenge. Score one for the gnarly roots of the world. A small price to pay, perhaps, for stubbing a tree's toe.

EXACTLY WHAT a 45-year-old adult is doing on a fat-tired, human-powered vehicle in the middle of the woods is something only a bike-loving psychoanalyst prone to the call of the wild could rationally dissect. Certainly the reasons are more complex than simple forward propulsion. We can start with the reborn youngster - a hearkening to carefree summer days on a Schwinn Spitfire, riding to the local swimming hole, exploring nearby woods via logging road, heading over to the first girlfriend's house for dinner.

It was a Schwinn clunker, in fact, that led to the birth of mountain biking 20 years ago. The fat-tire "paper-boy bike," introduced by German builder Ignatz Schwinn to America in 1933, had fallen out of favor in the lightweight-crazed late '60s and early '70s. But skinny tires were too fragile for fast off-road riding.

A group of cycling fanatics began riding refurbished Schwinns down a steep fire road on the back side of Mount Tamalpais in Northern California's Marin County. The rocky, wildly twisting road was soon nicknamed Repack, due to the practice of repacking rear brake cylinders whose grease had sizzled away on the descent. Drawing on more advanced road-cycling technology, the not inappropriately named Joe Breeze built the first "ballooner" designed expressly for off-road cycling, with hand brakes, derailleurs and extra bracing. Today Breeze's sleek "Breezer" bicycles are in high demand among cognoscenti, and cohorts Gary Fisher and Tom Ritchey have profited by marketing their pioneering roles as well. Even the old clunker itself is back, reissued as the Schwinn Classic Cruiser, complete with dashing white sidewalls and coiled-spring seat.

"It was pretty apparent early on that the bike struck a nerve," Breeze recalls. "Non-cycling buddies would ask to ride our bikes. They'd go down around the block and come back with big smiles on their faces."

Whatever inspired those smiles, it was catching. From its Marin County roots, mountain biking touched off the second coming of the bike boom. In 1976 there were no commercially manufactured mountain bikes. In 1983, 200,000 were sold. Six years ago, mountain bikes began outselling road bikes, which had been on their own fabled spiral since the Italian invasion of the mid-'70s. Today, incredibly, nine out of 10 bicycles sold are mountain bikes. By 1993, 32 million were in circulation. Mountain biking has grown to a $2.5 billion-$3 billion worldwide business whose prime innovators still reside in the U.S., a claim few industries can reliably make.

Today's fat-tired bikes have 17 to 21 more gears than their beefy ancestors. They weigh 10 to 20 pounds less. They have stronger, lighter wheels, exotic metals, "suspended" front forks and rear chainstays that absorb jolts in the terrain. Aided by a "peace dividend" - out-of-work defense technicians, many of them in aerospace - mountain bikes feature CNC (computer numerically controlled)-machined components that are light, strong and stylish. Mountain bikes are more stable than the 10- to 24-speed road racers popular in the '70s and '80s. You can sit on them upright. They get fewer flats. They will not go as fast, but are built for handling and comfort rather than speed. They feel safer.

Yet only about 7 million of the 32 million mountain bikes have made it off-road. And just a third of those represent hard-core, frequent trail riders. For most riders mountain bikes pose the same lure as four-wheel-drive sport utility vehicles and Sierra hiking boots that never go near dirt. It's the thought that counts.

"It goes back to this ingrained feeling as Americans that we're rugged individuals," said Jackson Lynch, associate editor of MTB magazine in Los Angeles. "With a mountain bike, even if you don't intend to go off-road, at least you can feel like you could if you wanted to."

I AM HAPPY TO have the privilege of "endoing" in the forest. Without mountain biking, I would seldom go into the woods. Hiking is too slow, too tame, too dare I say boring? On a mountain bike, you can do it faster and find plenty of challenge as well.

The problem is, for all its popularity - probably because of its popularity - mountain biking is increasingly under fire.

The Grouse Mountain path I munch dirt on, Oil Can Trail, is unmarked, dark, isolated and technically closed to the public. It is one of the vaunted projects of the semi-mythical Secret Trails Society, headed by the legendary Ross Kirkwood. There is no map, guide book or other official documentation.

The Secret Trails are known as among the most technical - difficult to stay upright on - in the world. The trail's names give some idea of their legacy: Sex Boy, Seventh Heaven and Severed Penis.

For mountain bike obsessives, the notion of secret trails conjures an inner glow of delight. The reason: You cannot ban what you don't know is there. Consider the case of the New Paradigm Trail near Mount Tamalpais. For five years it was a woodsy three-mile refuge, reachable only by trekking in eight miles from the nearest road turnout. Mountain bikers built it (over an estimated 4,000 person-hours), maintained it, nurtured it. In the eco-warzone of Marin, where cyclists get issued $200 tickets for exceeding 15 mph and where nearly all singletrack trails are off-limits, New Paradigm was paradise.

One day, someone ratted. The Marin Municipal Water District, aided by outraged hikers, destroyed the trail on grounds it was illegal and could set a precedent. "They destroyed it because it was a slap in the face - a clever answer to repressive forces," said Jacquie Phelan, a fat-tire pioneer best known for starting WOMBATS - the Women's Mountain Bike and Tea Society.

The moral of New Paradigm, the Secret Trails Society and other pantheons of the unknown rider: Keep it to yourself. You may get to ride it another day.

MOUNTAIN BIKE DEFENDERS in the Northwest fret about "Marinization" of the sport here. Because mountain bikers arrived late to the environmental boom, and because their numbers are sprinkled with a demographically predictable percentage of bad actors, they are the second-class citizens of outdoors culture. As soon as a trail, no matter how barren of hikers, climbers and strollers, becomes popular to mountain bikes, its managers start to come under pressure to ban them. In several cases - the Redmond watershed, for example - mountain biking has been established for years, only to come under fire recently as the sport boomed.

In the past, the anarchic, individualistic mountain biking "community" was prone to roll over and search out the next trailhead. A crushing blow was delivered early: In 1983, with the infant sport small and unorganized, mountain bikes were banned from designated wilderness areas. The original Wilderness Act, passed in 1964 before mountain biking even existed, contained no such provision. Thousands of miles of singletrack (narrow foot paths that mountain bikers lust after) were officially placed off-limits in a single act of legislation.

Trickle-down may not work in economics, but for the ban-the-bikes movement it did wonders. Consider some home-grown examples:

-- Banned on Cougar Mountain. After bikes were barred from this popular Issaquah Alp five years ago, the Backcountry Bicycle Trails Club (BBTC) formed to regain access. At more than 500 members, the club is the nation's largest. Cougar Mountain, however, remains off-limits. Cyclists are trying to gain access by working with planners of the proposed 2,900-acre Cougar Mountain Regional Park - to little gain, so far. An amendment to the park plan allowing cyclists use of six to eight miles of gravel road - not trails - failed by 11-2 in a King County Council vote last September.

-- Bikes banned from most of Tiger Mountain. Trailhead after trailhead extols the virtues of the approaching hike, punctuated with a small drawing of a bicycle encircled by the international no symbol. Exceptions are the Preston and Iverson railroad trails and a newly built Northwest Timber Trail, but riding on them during a sunny weekend can be the off-road equivalent of Highway 520 at rush hour. On any given weekend there are more mountain bikers on Tiger Mountain than hikers. Yet cyclists have far less access.

-- Ban in Redmond. Bikes were banned from an 800-acre section of the city of Redmond, which proudly advertises itself as the nation's cycling capital. About 25 years ago, motorcyclists carved twisty, stump-pocked trails throughout a section of second growth called the Redmond watershed (not actually a watershed). When hikers, equestrians and finally mountain bikers began flocking to the Novelty Hill site, motorcyclists moved on. Complaints gradually arose as the area became a mecca for mountain bikes.

Last fall the Redmond City Council, under pressure from equestrians and nearby residents, moved to limit mountain bikes to roughly one-third of the watershed usage. Hikers and equestrians would make up the other two-thirds. In reality, hikers are rare in the watershed and equestrian use pales next to cycling. When the city jumped the number of hiker hours from 1,092 (actual 1993 use) to 10,047 (1995 estimate), the BBTC sued to have an environmental-impact statement prepared. The suit did not sit well with the Redmond City Council, which in March voted to limit cycling to a single trail in the watershed. The plan is on hold, however, till the suit comes to trial in the summer.

-- Bikes banned on Grand Ridge. This 2,225-acre vista above High Point off I-90 is destined for planned community development of 3,250 housing units, 3 million square feet of office space and 425,000 feet of retail. Until the bulldozers come, it is one of the more popular cycling trails, and one of the weirdest. "No Trespassing" signs were recently posted on two state access bridges, but the adjoining dirt road remains open to use.

Riders, equestrians, dog-walkers, hikers and runners use Grand Ridge, but it technically is restricted from public use while the developer, Port Blakely, and King County work out a master plan. As much as 1,400 acres are earmarked for recreation, with the county to decide how the land will be used.

Coming bans? Biking leaders are trying to protect access to the Dark Divide, a challenging, breathtaking roadless area in Gifford Pinchot National Forest south of Randle; to St. Edward's Park off Juanita Drive near Kirkland; to the Middle Fork of the Snoqualmie River; and in the Skykomish district of the Mount Baker-Snoqualmie National Forest, where Iron Goat Trail Phase II and Alpine Baldy represent prime mountain-biking prospects.

Not all is gloom and doom. King County is putting together a committee to represent cycling interests. A trans-America trail is being developed from Canada to Mexico along the Continental Divide. A new sea-to-sky trail in British Columbia is drawing international attention. Winthrop is becoming as popular for its powdery singletrack in the summer as cross-country skiing in the winter. Crystal Mountain and Ski Acres are catering to mountain bikers, following the international trend to turn downhill-ski resorts into summer mountain-biking meccas. And mountain biking is gaining increased visibility: Next year in Atlanta it becomes an Olympic sport for the first time.

I AM ON MY hands and knees, scraping loamy topsoil from a gentle slope in Green Mountain State Forest northeast of Bremerton. Behind me, a motorcyclist smooths the surface with a rake. Above me on the hill, horseback enthusiasts use pickaxes to clear rocks from a new trail.

We are paying the dues of outdoor sport: Spending a rainy winter Saturday building a trail. In this case, the new trail will prevent further erosion to a creekbed. Between 20 and 30 of us are carving the path through underbrush along a rocky hillside. By midafternoon the new mile-long section will be complete. Just enough daylight for a quick ride around the forest.

Green Mountain, supervised by Department of Natural Resources forester Phil Wolff, maintains mixed-use trails for bicyclists, hikers, equestrians and motorcyclists. It is open to riding year-round. Along with Tahuya State Forest, to the south near Belfair, and Capitol Forest near Olympia, Green Mountain is a testament to the success of multiple use where all parties understand the realities of sharing.

"We've had better luck with everyone getting along than in other forests," said Wolff. "Maybe it's because we've improved things so much here. Motorcyclists have been banned from so many places, they're thankful to have an area to ride. And all the groups seem to understand that if you do segregate trail use, it means less for everybody."

Some of what brings us here is guilt. A survey by Mountain Bike magazine showed that 64 percent of mountain bikers consider themselves environmentalists. Mountain bikers love the outdoors; they just have a different way of expressing it.

Anyone who has spotted a tire track through a mudhole is convinced mountain bikes trash the ecology. Studies have done little to incriminate mountain bikes, however. A report by two Montana State University researchers in Mountain Research and Development journal last year found that horses and hikers disrupted terrain more than wheels. MTB Pro, a British mountain biking magazine, found in a comparative study that "so long as they avoid causing new rills on unvegetated downhills, they (mountain bikers) are probably doing less damage riding than if they'd walked."

Any activity causes environmental damage. The true source of eco wars is very simple: use conflict. There are too many people seeking to enjoy the same outdoor resource. A certain number of yahoos are bound to poison the well. Pioneer Joe Breeze, who has hiked on Mount Tamalpais since the age of 5, said he "could see it coming" as soon as mountain biking got popular: "There were bound to be a few bad apples who spoiled it for everyone."

While hiking I've had bikes come up too fast, too suddenly, for comfort. As a mountain biker I know no amount of civility - smiling, saying hello, even dismounting in tight quarters - will make all hikers happy. The outdoor experience we all cherish is becoming too rare a commodity, resembling a trip to the supermarket as much as an escape to serenity.

The forces of cooperation exemplified by areas like Green Mountain are gaining momentum elsewhere. Tim Blumenthal, head of the International Mountain Bicycling Association in Boulder, Colo., talks about building a "trails community" uniting all elements, from bikers to birdwatchers, against the common enemy - commercial exploitation and development. In office for just a year and a half, Blumenthal already has negotiated, with funding from REI, a thaw-bent mediation project with the Sierra Club to analyze and agree on trail uses on a case-by-case basis.

The basic approach: Give something up to get something back. In negotiating use on newly designated trails, the mountain biking contingent is focusing on prime-time riding trails while agreeing to forgo areas heavily used by hikers and horseback riders. Not everyone agrees with the mediated approach. Experienced mountain bikers feel "we've already had so much taken away from us, there isn't much left to compromise over," notes John Zilly. He sees hope for designating certain areas mountain-bike-only, similar to what horseback riders have in the Eastside's Bridle Trails State Park. Beyond that, trails could be marked primarily for biking use as a "heads up" to hikers, horseback riders and other users.

CECILE IS GOING through our mail, dropping piece after piece into the yellow recycling bin.

"When will the magazines start coming?" she asks.

"Beg pardon?"

"The mountain bike magazines. Aren't you going to start subscribing?"

"I hadn't thought about it," I prevaricate.

"How many mountain bike magazines are there?" she asks. I can smell a trap. Some people's lives are not so much an open book as an open magazine.

First it was sound systems. Stereo Review. Hi-Fi Review, Popular Electronics, Stereophile.

Then tennis. Tennis, Racquet Sports, Tennis World.

Modern Photography, American Photographer, PHOTO, Shutterbug.

Road riding: Bicycling, CycleSport, Velo News, Winning.

And now, Mountain Bike Action. BIKE. Mountain Biking. Mountain Bike International, MTB Pro (both British). Dirt Rag. MTB.

One wishes it stopped at mere paper. Now there's the Internet! Prodigy! CompuServe! America Online! With online access 24 hours a day there is no longer any excuse not to think, breathe and talk mountain biking around the clock. The best trails to ride, what to take to eat, the latest trick equipment, full suspension versus hardtail.

It's largely a white male world. But bike manufacturers, recognizing the buying potential of women long frustrated by too-big road frames, have begun constructing small frames aimed at the female market. On a recent ride on Grand Ridge I counted nearly as many women as men, several Asians and three blacks. Oh, and two entire families, pets included.

IT IS DARK AND cold. I have just returned from a mud-thrashing ride east of Issaquah. My face, jersey and legs are caked with crud, my brake pads make sandpapery sounds as I wheel my splattered bike up the walkway. I'm shivering and coughing.

Cecile greets me at the porch, gives me a long look up and down, crosses her arms and, shaking her head, says, "How long is this one going to last?"

I wish I knew. Bent over in arthritic misery, moving slower than I ever thought practical, I'm already contemplating the next trail - a rubbled death march near Whistler, endless singletrack above Winthrop, lunar slickrock at Moab, crazed downhill at Mammoth. You can take a biker out of the mountains, but you can't take the mountain out of the biker. There are times when one is better off misunderstood.

It's a mountain biking thing.

------------------------- MOUNTAIN BIKING RESOURCES -------------------------

Backcountry Bicycle Trails Club: P.O. Box 21288, Seattle, WA 98111-3288. Or call 283-2995.

International Mountain Bicycling Association: P.O. Box 7578, Boulder, CO 80306. (303) 545-9011.

Internet and online access:

http://www.compumedia.com/agb/bbtc, the home page for the Backcountry Bicycle Trails Club.

http://www.starwave.com for "Outside Online," an outdoors-sports service from Bellevue-based Starwave.

http://www.echonyc.com/hadley/wombats/wombats.html, for women cyclists. (WOMBATS stands for Women's Mountain Bike and Tea Society.)

Internet newsgroups dedicate megabytes of electrons to the sport: rec.bicycles.marketplace; rec.bicycles.off-road; rec.bicycles.soc.

Commercial services - America Online (e-mail cycleOpath, thecyclist, bikeleague), CompuServe, Prodigy - have e-mail groups and outdoors sports forums.

And still on paper:

"Kissing the Trail," by John Zilly (Adventure Press, $10.95).

"Mountain Bike Adventures in Washington's North Cascades" and "South Cascades," by Tom Kirkendall (two books from The Mountaineers, $12.95 each).

--------- BIKE TALK --------- Endo: Short for end-over-end, to crash headlong. Stacker: Fall off the bike in a heap. Faceplant: Just what it implies. Singletrack: Narrow dirt path, often in remote or wooded areas. Clean: To ride a tough section without touching ground or falling off, e.g., I cleaned that hill. Doorstop: A hidden root or rock that causes the bike to stop, throwing off the rider. Technical: Difficult to ride, with roots and other obstacles. Shred: To ride fast and hard, as in shredding a trail. Catch big air: Go airborne. Gnarly: Difficult. Challenging.

---------- KLEINFELD: ---------- WHY A MOUNTAIN BIKE HANGS IN JERRY'S CLOSET

How much do men love their mountain bikes? An incident from TV's Seinfeld gives a clue.

When the Seinfeld set was being put together Michael Richards, aka Kramer, suggested hanging a green Klein mountain bike in Jerry's closet. Richards, an avid mountain biker, owned one of the Chehalis-made bikes, designed by MIT-trained engineer Gary Klein. The Klein soon became as much a Seinfeld icon as the Apple Macintosh on the corner of his desk.

Richards, who attended Evergreen State College, knew all about Gary Klein and his storied mountain bikes. Tricked out, expensive (a top-of-the-line model can run $4,000 or more), using lightweight fat aluminum tubing, Kleins are the sport's Porsches. Klein owners the world over could point to Seinfeld's closet and say proudly, "I've got one of those."

One day, after dozens of episodes, the Klein was replaced by a competing brand - Cannondale, which also uses fat aluminum tubing. Its product-placement folks had persuaded the Seinfeld set producers to make the switch.

Klein partisans went ballistic, writing the show's producers and complaining in letters-to-the-editor sections of bike rags.

"Michael Richards got upset," said Klein's Phyllis McCullough. "So they put the Klein back."

Cannondale's response was to issue a milk carton picturing the Seinfeld model framed with boldface words, "Missing: Have you seen me?" No one paid attention. Mountain bikers do not drink milk.

Paul Andrews is a reporter for The Seattle Times. Benjamin Benschneider is a Times photographer.