For years, there have been runs and triathlons just for women, notes Teresa Robbins, founder of Venus de Miles, a women-only charity bike ride in Boulder.

"But we're just picking up steam in women's-only cycling," Robbins says.

It's hard to say how much the demand for only-for-women cycling events, clinics and clubs in Boulder has increased. But some events that cater exclusively to female cyclists -- such as the Venus de Miles -- have increased participation every year, and anecdotal evidence from those offering women-only cycling programs points to an increase as well.

More women are riding bikes every year, says Brandon Dwight, owner of Boulder Cycle Sport, which is why he's dedicating extra space in his new store in south Boulder to women's cycling gear.

"It's the fastest growing demographic in cycling," Dwight says.

Join the club

Membership in the Venus de Miles women's cycling club -- which was inspired by the ride -- is up this year, says Karli Gronholm, co-founder of the club. Last August, the club -- in its first year -- had 110 members. This year, it already has 170.

"I think the last five years -- and it could've been longer, but that's when I started noticing it -- women started talking about women getting together and getting out on a bike," Gronholm says.

And the American Cycling Association, the organization that sanctions road and cyclocross races in Colorado, started a mentoring program for women who want to try racing this year. Spokeswoman Laura Kindregan says the ACA started the new program based on feedback from the community.

The demand for women's cycling clinics has been pretty steady in Boulder, says Kristin Weber, of Boulder CycleChix. Through different iterations of CycleChix over the past 10 years -- and starting with the Schwinn Homegrown team -- Weber has worked with other former racers to promote women's cycling and offer several women's cycling clinics every year, like mountain biking skills and bike maintenance.

"We'd have 60 to 80 people show up at the clinics six years ago, and it's about the same now," Weber says. Then again, she says, more bike shops around town are offering women-only clinics.

"We have more free clinic competition, which is fantastic, in my opinion," she says.

Venus riders up

Participation in the Venus de Miles ride, which will take place this August for the third time, more than doubled the second year, Robbins says, from 661 to 1,430. She's expecting 3,000 women to participate this year.

"Consistently from month to month, we're double where we were last year" on registration, Robbins says. "It just shows you what a market there is for it."

Gronholm, co-owner of Full Cycle bikes, says she doesn't look at this as a trend, because the word "trend" implies that it will fade.

"Women are learning and empowering and having fun and finding new groups to ride with and solidifying a place in the cycling community for themselves," Gronholm says. "I don't think it's going away. We're just going to be out there, feel stronger, ride more."

Kids, too

Kate Rau, coach for Singletrack Mountain Bike Adventures, a youth development program, revived SMBA's girls-only mountain biking program again this year "just because of the need to get more girls back on bikes."

"When I had it before -- I think it was '04 -- we didn't sell the camps," she says. "But now there's all kinds of women-only cycling things."

Rau says she hadn't had more requests for a girls-only cycling program at SMBA. But she hopes she'll get more interest now.

"It's kind of a chicken or the egg thing."