The Tri-Town Bike Riding Club has been formed by the recreation departments in Marion and Mattapoisett, with the group’s inaugural ride scheduled for Sunday, starting at 11 a.m. at Washburn Park in Marion off Route 105. Three rides are planned for riders of all abilities, said Marion Park and Recreation Director Jodi Dickerson. The rides are free, but waivers must be signed, he said, and helmets are mandatory. “It came about when some avid riders were talking about forming a club,” Dickerson said. “There will be three loops the first ride — one each of five, eight, and about 30 miles. We’ll try to do it until the snow flies.” Future rides will be developed based on preferences of club members, he said. For information, call 774-217-8355. Full story for BostonGlobe.com subscribers.