Biking boom prompts a wave of non-pedaling adults to sign up for lessons "D.C. has become such a bike town; it's everywhere," said Chris, a 29-year-old staffer at a child advocacy group in the District. He stills bears the scars of his disastrous first attempt to learn at age 7: a small one on his ankle and an enduring one on his self-esteem. "I got my foot caught somehow and went down," said Chris, who asked not to be identified by his last name because he doesn't want to be known as one of the few adults who never navigated such a basic rite of passage. Everyone knows how to ride a bike. It's embarrassing. Embarrassing seems to have become unbearable for many of the area's non-biking adults; thousands of them are fueling a boom in adult learn-to-ride classes. The Washington Area Bicyclist Association is holding 14 adult-only classes this spring and summer, including some courses that cost as little as $1o in the District, Alexandria and Arlington. The association may add more adult classes to meet the soaring demand, and other groups offer similar classes. "As soon as we add a class, it fills up," said Matt Liddle, who runs the outdoors education program for mid-Atlantic REI stores, where a four-hour session costs $85. The interest has been particularly acute in Washington, where even Supreme Court justices are tooling around on bikes - and sometimes toppling off them. On Saturday, 74-year-old Justice Stephen Breyer had shoulder replacement surgery at MedStar Georgetown University Hospital after fracturing his shoulder in a bike tumble on the Mall. It was the third time that Breyer, who is expected to make a full recovery, has been injured riding a bike. Despite those kind of mishaps, the region's bicycle renaissance has nudged non-riders to seek a way - ideally a low-profile way - to catch up. "Not knowing how to ride a bike as an adult is not something you admit at a cocktail party," Liddle said. "You don't want to ask a friend, "Hey will you teach me?" " Perfecting their balance At the Sunday morning class in Alexandria, nervous novices lined up with loaner bikes along the paved yard of an elementary school. One had her helmet on backward. And yet most of them, the instructors promised, would master the basics by the end of the three-hour class. As for why it's taken this long, instructors heard the usual laments: For 27-year-old Josh Krantz, it was growing up in the Bronx, where stories of bike thefts and bike wrecks dissuaded his parents from getting him on a two-wheeler. For Zainab Kamara, a 42-year-old accountant, it was being born into a non-riding family in a London neighborhood where cycling was not that common.