David Lipow, a lawyer, used to take the train from Exton to his office in Center City every day.

Six weeks ago, that changed.

Now, Lipow is driving to Conshohocken and riding his bike the 13 miles to work on as many days as he can, joining a slowly growing number of people commuting on two wheels under their own power.

The reasons are not limited to gas prices hovering around $4 a gallon. Exercise and the joie de vivre of being outdoors regularly top the list.

"It's exhilarating and I love it," Lipow said. "I have to recognize that when I'm on my bike, I'm living for the moment. . . . The only thing that is guaranteed is the moment, this moment. Five minutes from now is not guaranteed."

His only complaint: the lack of manners of other cyclists on Kelly Drive, particularly those who fail to announce that they are passing.

The Bicycle Coalition of Greater Philadelphia estimates that 19,000 people commute by bicycle on a typical day in the region, 11,000 of them in the city, an increase of 15 percent over last year.

"Most trips are less than five miles," said John Boyle, the coalition's advocacy director.

As if to acknowledge that growth, the Philadelphia Parking Authority joined the coalition last week in announcing the installation of free bike racks at three garages and a surface lot in Center City.

The coalition says thousands more racks are needed, but praised the PPA for taking a lead in the effort.

In another indication that bicycle traffic is increasing, an unscientific survey of bicycle shops in the area showed sales were reported up.

And perhaps a better sign of this can be found at the Bike Line outlet on Arch Street near 11th. Manager Bob Prince said walk-in, same-day repair jobs are keeping him and his crew busier than ever.

"We have a lot more repairs coming in, like flats, and people waiting while the work is done," Prince said. "It's getting crazy from 3 to 6." In other words, during the evening rush hour.

Bicycle commuting is not for everyone because of its hazards and inconveniences, some of which are being addressed.

Advocates, for example, say SEPTA Regional Rail is hardly friendly to bicylists, especially at rush hour. But they also note that bike carriers on SEPTA buses are seldom used, and they point to NJ Transit's River Line as a model of accommodation with its onboard hanging racks.

Boyle said plans to introduce a bike-sharing program in the city could prove to be a boon to transit commuters who would like to have a cycle at both ends of their trips.

Still, for anyone considering bicycle commuting, issues such as a need to change clothes or get a shower at work might be a deterrent.

Heather Riley, a Midwest transplant who bicycles from Germantown to her job as a graphic artist in Northern Liberties most days, has found a solution for that.

With the money she is saving by bicycling, she is paying for a membership at a gym near her office where she can shower and change.

"I like being free as a bird," Riley said of her eight-mile ride that takes her along Kelly Drive.

When it comes to bicycle commuting, few have the experience - or experiences - of Bill Gugel, who started making his way to work under his own power when his last car was stolen 20 years ago.

In that time, the sinewy 51-year-old project designer has established a nodding acquaintance with dozens of people along his 10-mile route between his home in Gloucester City and his office in Center City.

Many of the new faces he is meeting also are on two wheels.

"I'm definitely seeing more bicyclists," said Gugel. "It's not a whole lot. There's always room for more."

For Gugel, who has seven bicycles and a trailer for camping trips, the two-wheeler he uses to get to and from work is a matter of function over form.

Instead of a lightweight, multispeed road bike, he rides a single-speed beach cruiser outfitted with baskets that carry two plastic tubs with his change of clothes, rain gear, and tools for any repair.

A license plate on his front basket announces, "God is my pilot."

For his ride to work, he hugs the Delaware River, staying away from some of Camden's worst neighborhoods while enduring some of the city's most challenging spots.

Once, he recalled, a teenager pointed a rifle at him as he rode to work.

"I begged him not to fire," Gugel said. "Then I felt three sharp pains in my back. I wondered if this is what it feels like to be shot."

But it was BBs and not bullets that hit him.

Gugel rides year-round, but in severe weather will opt for the bus. The hardest part of the ride, he said, is hauling his bike up the three flights of stairs to the open walkway across the Benjamin Franklin Bridge.

"There's no better way to go to work," said Gugel, who cannot recall the last time he was stuck in a bumper-to-bumper traffic jam.

"I literally save thousands of dollars a year, what with no car insurance, car payments and, obviously, gasoline," he said. "I'm making money by saving it and I'm keeping myself healthy at the same time."

And his plans for the extra cash?

"Maybe buy myself another bike."

Contact staff writer Joseph Gambardello at 215-854-2153 or jgambardello@phillynews.com.