The Mini-Skirt Mob (1968)

Shayne, the leader of a Honda-riding biker gang known as the Mini-Skirt Mob, has been jilted by her lover, cowboy star Jeff Logan who has married straight-laced Connie. Shayne enlists the rest of her gang to help her break up the newlyweds and get Jeff back - even if that means killing him in the process. Her revenge escalates until her sister Edie is killed by a Molotov cocktail and Shayne finds herself hanging by one hand over a deadly chasm. Should Connie let go before Jeff returns with the police?