Lea Davison knows that 9-year-old girls can put you in check quickly. On a recent weekend, while riding around with a crew of pre-teen girls, she got owned in a game of King of the Hill. "Lea came in top 10 in the world and the girls are like, 'Sure, but can you ride to the top of that mulch pile?'" her sister Sabra says.

Lea, one of the world's best female cross-country riders, has spent time on the top of some much bigger mulch piles. She finished second in the 2015 World Cup in Lenzerheide, Switzerland, competed in the 2012 Olympics, and last year, after hip surgery in January, placed third at World Championships in September. But despite her laser-beam focus on racing (and on recovery), she's also been spending a lot of time getting girls on bikes through Little Bellas, an on-the-bike mentoring organization that she and Sabra founded and run.

Eight years ago, on the start line of a community race in their Vermont hometown, the Davisons noticed one older woman hanging back. They pulled her into line with them, and that woman, Angela Irvine, started talking about how to empower women through biking. It didn't stop there. The conversation continued after the race, and ultimately the three hit on the idea of a bike camp for pre-teen girls, where they could create a culture of riding and community.

At their first session, at the Catamount Outdoor Family Center in Williston, Vermont, there were 12 mentors and seven girls. It felt like a bust, but after an article ran in the local paper, twice as many girls showed up the next week. From there it kept expanding. "The growth has been pretty incredible," Sabra says. "We're going to get 350 girls on bikes this summer."

Lea Davison

Lea, now 32, started racing for the local mountain biking club in high school, and at 18 unwittingly qualified for the World Championships during a race at Mount Snow. "That was the turning point in my career," she says. "I figured out that women could make a living racing mountain bikes and there was a world championship. From that point on, I set my sights directly on becoming a professional mountain biker." She raced for a junior development team, Team Devo, through college at Middlebury, winning the Eastern Collegiate Cycling Conference road title and Collegiate Mountain Bike Nationals along the way. She won U-23 Nationals the year after she graduated, landing her a spot on the Trek/VW squad. These days, Lea races for Specialized Factory Racing, the team she joined in 2011.

But as she moved up the ranks, she found fewer role models, less competition and less camaraderie. And mountain biking seemed to have a bigger gender gap than skiing, or any of the other sports she had competed in. "There were definitely circumstances where you felt the repercussions of not having girls in the sport," Sabra says.

So they started the Bellas to try to change that. On some level, it's a simple economy of scale: The more girls they get on bikes, the more girls there are on bikes. That means more well-rounded competition and more people pushing the sport to progress and even out. But it runs deeper than that. They've also seen how riding can help girls individually–how it makes them more confident and more comfortable in their bodies.

"Sometimes in the world of pro cycling things can get really narrow," Lea says. "We want to use Olympics and all that to inspire little girls, but we don't really coach at all. We don't talk about the difference between girls and boys. We just try to be strong role models."

Lea Davison

Little Bellas started out with Sunday sessions, when the girls would meet and ride on Sunday afternoons. From there it expanded to week-long camps in Vermont, and in 2010 Little Bellas went national, with a camp that coincides with the Sea Otter Classic in Monterey, California, so they could pull in more mentors. All the girls at the camps get to spend time with pro athletes. Little Bellas has expanded to three new chapters: Monterey, California; Denver, Colorado; and Woodstock, Georgia. "My vision for the program is to try to blanket the U.S. with girls who ride their bikes and absolutely love it," Lea says. "We've seen it reverberate through the communities we've been in and grow in a quality way."

It's growing in a quantifiable way, too. This year, when registration opened on February 1, the Vermont sessions filled up in 15 minutes. "There are moments when we just step back and there are 40 girls riding around and it's like, 'Wow, we really did it,'" Sabra says.

For all the growth and forward movement, it's not always easy to run a thriving nonprofit when you're also trying to compete. Lea already has her eyes on the 2016 Rio Olympics, and she wants to stay on the World Cup podium. She's focused and positive, but her racing job often keeps her away from home and the Bellas business. Sabra is an athlete, too–a Nordic ski racer–and her season is demanding as well. "We're basically on opposite schedules," Lea says. "It's like, 'Tag, you're in, now I'm racing, it's your turn to answer emails.'"

Lea and Sabra are also trying to change the system in bigger ways. They've handed out dozens of scholarships to make sure they never turn a girl away for financial reasons, and they're working on leveling the financial playing field. When the Catamount Outdoor Center, home of the first Little Bellas camp, was picked to host the Pro XCT Finals in 2012, they lobbied sponsors for extra prize money to close the gender pay gap. According to Lea, female pro XC racers are usually awarded 66 percent of what their male counterparts earn. "G-Form came on and sponsored the prize purse, so the women were paid the normal percentage more than the men," she says.

Ultimately, they want to make riding like their first race with Angela, where the wheels started turning. "Women don't always get invited to the front line," Lea says. "We wanted to create that experience in cycling.”