A parade of Motor Maids bikers winds its way down Lisbon Street in Lewiston on Wednesday evening. More than 270 women, from as far away as California and Canada, were in town for the 69th annual convention. The all-female motorcycle group is known for its uniform of blue shirt, white vest and gloves. It was the largest convention in the group’s history, said New England district spokeswoman Melanie Jandreau.