LYNNFIELD – The sixth annual Reid’s Ride, a 28-mile bike-a-thon from Lynnfield High School to Stage Fort Park in Gloucester is Sunday.Proceeds of the event, held in memory of Reid Sacco of Lynnfield, benefit the Reid Sacco Memorial Cancer Research Fund, which supports programs, projects and advocacy toward cures for cancers, particular cancers that strike youth and young adults.Reid Sacco passed away in April 2005, at the age of 20, after a two-year battle with sarcoma.Cyclists leave the starting line at Lynnfield High at 7:30 a.m. and festivities at Stage Fort Part in Gloucester wrap up around 1 p.m.For details about the course, how to register to ride, sponsor riders or donate directly to the foundation, visit Reid’s Ride Web site at www.reidsaccofoundation.org.