Young bike riders, ages 2 to 12, can join the Pan-Massachusetts Challenge campaign to raise money for cancer research through the Natick PMC Kids Ride event May 20 at Belkin Family Lookout Farm. More than 6,000 riders are expected to participate in PMC Kids Rides being held throughout the state. The Natick event requires a $10 registration fee and a minimum fund-raising commitment of $25. It will feature two courses for riders, based on age groups, from 8 to 11:30 a.m. There will be an after-party for riders and their families, complete with entertainment and food. To register, visit kids.pmc.org/natick. PMC Kids Rides have raised more than $4 million to support research at the Dana-Farber Cancer Institute since 1998.