JAN CHARRETTE donned her helmet in her second-floor office. She grabbed her mountain bike, and rode the elevator down. Colleagues eyed her curiously.

"My Honda normally parks right there," she pointed to a corner spot in the hillside parking lot, squinting in the afternoon sun. Then she turned west. Her two-mile ride home wound its way through the hills there.

"No driving today," she said as she rode off.

Charrette recently started cycling to work a few times per week. At age 50 and admittedly out of shape, her main reason was exercise. She also wanted to save money on gas and do something for the environment.

So now she gets up earlier, packs lunch (no driving home to eat at noon), skips her beloved coffee shop (no cup holder on the handlebar), and arrives at work breathless and red.

It's definitely a challenge.

"I'll be honest," she wrote in an e-mail. "That hot day we had the other day, biking home with the sun in my eyes and panting up those hills, I had second thoughts."

She won't give up just yet, but she knows she needs more than stronger legs. She needs stuff. A fender rack and a trunk bag is a must, for one, as is a mounted water bottle. Before long, $100 will be gone.

If she sticks to biking, she might spend more, too. She likes her bike for now, but it clearly doesn't fit her needs; the frame is heavy, the wheels are bulky and the brakes and gears could use updating. Then come the windbreakers, the shoes and gloves, a better seat.

Charrette is set to join the burgeoning bicycle marketplace.

A growing group

By most accounts, people like Charrette are taking to the streets in ever greater numbers. They are spurred by gas prices nearing $4 per gallon; horrendous traffic conditions that are vulnerable to disruptions, such as the recent collapse of the Interstate 580 connector; an increasing concern for the environment; and an ever stronger focus on health and fitness.

They bike to commute, for errands, recreation and other activities. As they get more experienced, they will bike farther and more often — and spend more on their bikes, too.

Some take it pretty far. Phil Carter, an aviation engineer, avid cyclist and occa sional bike racer, has made his friends jealous with his 21-mile bike commute between Oakland and Walnut Creek.

"A buddy of mine does only five miles each way," Carter said. "He says it's not enough for him."

At least four days a week, Carter starts near Piedmont, rides through the Oakland hills, descending into Walnut Creek through Moraga and Lafayette. The location of the office, allowing that route, was part of the reason he chose this particular job, he said.

Before he was married with a child, he would spend a substantial chunk of his paycheck on bikes, Carter said. Now he rides a bike he assembled himself, and his total gear costs about $2,000.

Across a wide spectrum of experience between him and Charrette, thousands have begun to jump on the bandwagon. The Metropolitan Transportation Commission discovered "the first significant increase in bicycle commuting in years" in its 2005 Commute Profile. Membership at the Northern California and Nevada Cycling Association nearly doubled in the last decade. Some 12,000 people belong to cycling organizations in the Bay Area alone.

"Bike racks at BART stations are filled," said Robert Raburn, executive director of the East Bay Bicycle Coalition. "Bikes abound aboard, too. They are also there on any street with a bike lane."

Real growth is yet to come, though, said Sabrina Merlo, regional advocacy director for the Bay Area Bicycle Coalition. She cited another MTC study which found that almost half of the Bay Area's residents both live and work within half a mile from public transit — all forms of which accommodate bicycles. Expand that to two miles — an easy distance to cover on a bike — and you could have most people in the Bay Area using bikes and transit, leaving their cars at home.

Moreover, a good proportion of locals don't even need public transit. According to Dave Favello of the East Bay Bicycle Coalition, even in spread-out Contra Costa County thousands of people drive less than six miles to work, school or amenities. An average cyclist spans that in less than 30 minutes.

Yet, people in Contra Costa do the least nonrecreational biking in all of the Bay Area, at far less than a single trip per person per week. Other counties don't fare much better: Alameda County, where utility biking is highest, still has far more drivers than bikers.

That spells an impending bike boom, these advocates say. That, in turn, means booming business in hundreds of bike shops and more than 200 bike-related manufacturers in California and beyond. Bike merchants say they are busier than ever.

An ever-changing business

Little as we bike now, we easily outdo the'50s, when serious bikers were so unusual here that they all knew one another. Peter Rich, 66, a bit of a local biking legend, was even jailed a couple of times in the post-war era.

"The cops considered an adult on a bike to be so off, they thought it must be illegal," he said. Of course it wasn't, and he was let go both times.

The history of Velo Sport, the 45-year-old bike shop Rich founded in Berkeley, is a case study of the changing bike scene in the Bay Area. Rich started with racing bikes — a premature move in the car-centric postwar prosperity. Racing, wildly popular in the'20s and'30s, had all but vanished. Only kids' bikes remained.

Rich did very little business for eight or nine years. Then the market exploded: His business grew a hundred-fold between 1967 and 1972 even as his market share plummeted. That was the dawn of a new era in cycling.

Seemingly every year, new categories were born: road biking, mountain biking, BMX bikes, city bikes, cruisers, folding bikes, hybrids — then even further, into subcategories such as downhill, off-road or triathlon bikes.

Now, in the era of the Internet and cheap mass-produced bikes, bike shops are losing some of the market in accessories and lower-end bikes. Their new role is in service and quality gear. Larger, shinier and typically dominated by a single brand, bike shops aim for the more affluent customers, and try to keep them coming back. Most shops are unique; chains rarely survive.

A new form of retail

While Velo Sport still preserves some of the old, clubby atmosphere, other bike shops have made a bolder leap. Alameda Bicycle, for instance, recently got a glossy new face-lift that resembles a clothing outlet more than a place to retool your brakes.

"Before, we sold the bikes, but not the lifestyle," said owner Gene Oh, 30, who recently took over from his parents, the founders of the shop 20 years ago. "We had to transform customers into clients, employees into staff. We had to get rid of that ... dirty ol' bike shop." He picked up a shred of paper from the spotless floor. "I'm nostalgic, of course, but we don't want a cramped, overstocked space."

Accessories are spread loosely on shelves around the front, and three rows of bikes line a wall, each with a quote on its price tag.

"Get a bicycle," says one Mark Twain quip on a $600 mountain bike. "You will not regret it if you live."

It's surprising how little people know of bikes," Oh said. "Some customers ask how to use the brakes or the gears. They need to feel that's OK. Before, the grungy environment scared them off."

For bike store owners small and larger, that personal connection is the chief advantage over big-box stores, which flood the market with low-quality bikes that often cost less than $100.

"The low-end marketplace is kind of going away," Oh admitted. "But only we know our customers by name."

Community is key. Some bike stores learned that the hard way. Dave Guettler, former co-owner of San Francisco's Pacific Bicycle, bought a store in the city in 1984 with a partner. Riding the mountain bike craze, they expanded into a half-dozen branches within a decade. Guettler, however, felt that quality couldn't keep up with quantity. He opted out.

"It was too much to handle," he said. He moved to Portland, Ore., and opened a single superstore on 15,000 square feet, just as cycling exploded in that area. River City Bicycles took off: Within nine months, he did as much business as smaller stores in three to four years.

Pacific Bicycle, meanwhile, beefed up to a dozen stores only to deflate and move to a single large facility in downtown San Francisco. Only one satellite, in San Jose, remains today.

The Bay Area's large and affluent customer base forces these changes. They buy bikes for $300 to $3,000, supporting a large network of stores. Their expectations for service match their spending: To these customers, biking is often a way of life.

A lot to do

Bike shops and manufacturers jumped at the opportunity and started to advocate that way of life, teaming up with nonprofit groups to lobby, educate and organize events such as the recent Bike to Work Day.

What they do is good for the greater good, and just as good for business. But they have a long way to go.

For Charrette, a free "biking in traffic" course from 511 Contra Costa was the final push. Enthusiastic, now she plans eventual trips beyond Martinez.

Biking to the North Concord BART station or the Martinez Amtrak station could get her on public transit, allowing her to explore most of the Bay Area. Still, the infrastructure is spotty at best.

"Going up the hill, I'm often scared," she said. "I have to get off and push my bike at the busiest stretches. I'm concerned for my safety."

Indeed, bike infrastructure is vital to get more people on two wheels, experts say. It's only through that upgrade to the road system, plus massive storage around transportation hubs, that helped places like the Netherlands reach a 40 percent share for bikes in traffic. The Bay Area average is 1.5 percent; Berkeley tops local cities at 5.6 percent. The most bike-friendly city in America is Boulder, Colo., at 20 percent.

Still, the potential is there, says Merlo of the Bay Area Bicycle Coalition.

"Given our weather, we could do so much more," she said. "Why can't we be as good as Amsterdam?"

A series of legislative efforts are under way to ensure a favorable bureaucratic climate, she said. The Complete Streets Act would mandate California's road builders to consider cyclists when designing roads. The federal plan for a Bike Commuter Act aims to give a tax break to employees who bike to work.

"With over (half) of the working population commuting 5 miles or less to work, bicycles offer the strongest potential for reducing single-occupancy vehicle trips," U.S. Rep. Earl Blumenauer, D-Ore., the bill's sponsor, wrote on his Web site.

A practical issue

In Contra Costa County, where typical commutes are the longest West of the Mississippi, even the best bike paths can't get too many people to shed two wheels. Sweating across hills and in all sorts of weather, an hour or more each way, is not an attractive proposition to most people.

Phil Carter, the engineer who bikes 21 miles to work, has solved that practical issue. To him, "sweating is not a problem. I get in, use a wet cloth to take a birdbath in the restroom, then I take out my shirt from my backpack, and in ten minutes, nobody can tell" that he biked in, he said. "Anyway, in the morning I just cruise. I get my real workout on the way home."

Contact Marton Dunai at (925) 952-2671 or mdunai@cctimes.com.