Hell's Angels '69

In this classic exploitation film from 1969, two brothers cook up what they believe is a great plan to go undercover as Hell's Angels bikers to provide a cover for their planned robbery of Caesar's Palace in Las Vegas. After the robbery, the two escape and change into nice clothing, believing their new appearance will throw off the police. What they didn't count on is the Hell's Angels don't like to be played for fools. (official distributor synopsis)