Andy Greif, the founder of the Community Bicycle Center, is stepping down from his position as executive director of the Biddeford nonprofit.

The Community Bicycle Center serves 400 Biddeford children each year through free bicycle-related activities. Participants – many as young as 9 or 10 – learn how to repair and build bikes, go on group rides, make art with bicycle parts and work closely with volunteers and other adults in the community.

Greif started the city’s first Earn-a-Bike program in 2001 and later created the Community Bicycle Center to help youth develop life skills through bicycle activities. The center emphasizes mentoring relationships, civic engagement and safe cycling skills. Under his leadership, the bicycle center added programs and expanded from a small workshop to a 4,200-square-foot building.

Greif’s resignation is effective Dec. 31. He and and his wife have decided to move to Taos, New Mexico, at the end of the year, according to an announcement from the organization.

“We have and will continue to positively impact the lives of kids and the adults who mentor them,” Greif said in a statement announcing his resignation. “I am reminded of this fact by the note a participant recently left on my desk, ‘If I hadn’t found the CBC, I wouldn’t be the person I am right now.’ ”

Leanne Kazilionis, president of the center’s board of directors, said the board will spend the next few months refreshing its strategic plan, conducting a search for a new executive director and continuing its regular program. The board will announce an event to celebrate Greif’s departure and welcome a new director in the fall.

“We cannot thank Andy enough for his dedication, passion, leadership and expertise in developing the CBC into a locally and nationally respected youth development organization,” Kazilionis said in a statement. “We are in a strong position to continue providing opportunities for youth to grow during this period of transition and into the future.”

When Greif started the bicycle center, one volunteer served a handful of kids. It now has four employees, dozens of volunteers and 400 participants each year. In 2014, the center raised more than $476,000 to buy and renovate a permanent home for the center at 45 Granite St.