"started riding at a later age because of parental apprehension"

The nine core members are mostly Latinas in their 20s from Boyle Heights, East Los Angeles and Lincoln Heights who work for nonprofits. Each month, they organize a women's "Luna Ride" during the full moon, usually around their neighborhoods.

Their August ride, the biggest of the year, was a takeoff on Critical Mass, a monthly ride that spread from San Francisco to 300 cities, including Los Angeles. Just over 100 female riders joined the 30-mile ride from the Watts Towers to Hollenbeck Park, making five other stops along the way. They often choose political themes for their trips; July's was the California prison hunger strike.

The women also sponsor coed rides — although the men might have to listen to a lecture on male privilege and machismo.

Cycling is growing among young women but still lags far behind men's participation; only one in five riders in Los Angeles is female, the Los Angeles County Bicycle Coalition reported in 2011. The cyclists believe more women will turn out for rides with a female stride.

With male riders, "there's that whole bro-ish kind of stuff," Aguirre said. "We're not about who can ride fastest, we're about sisterhood."