Ralph Hubert Barger was born in Modesto, California, on October 8, 1938. His mother abandoned the family when Barger was four months old, leaving him and his older sister Shirley to be raised by their grandmother and alcoholic father. Growing up in Oakland, he was suspended from school several times for assaulting teachers, and he often fought with other boys. He dropped out of school in the tenth grade.
Barger joined his first motorcycle club, the Oakland Panthers, in 1956. After that club disbanded, he started riding with another group of bikers, one of whom, Don "Boots" Reeves, wore a patch – a small skull wearing an aviator cap set within a set of wings – that belonged to a defunct motorcycle club in North Sacramento
Barger was employed as a machine operator from 1960 to 1965, when he was dismissed due to extended absences. His criminal record began in 1963 after he was arrested for possession of marijuana. He was arrested again on the same charge the following year, and for assault with a deadly weapon in 1965 and 1966
According to former Oakland Hells Angels chapter vice-president George "Baby Huey" Wethern – who later testified against the club and entered the Federal Witness Protection Program – in his 1978 book A Wayward Angel, Barger convened a meeting of the leaders of the Hells Angels and other California motorcycle clubs in 1960 in which the various clubs parleyed over the mutual problem of police harassment.
The clubs voted to ally under a "one percenter" patch to be worn on their respective colors. The term refers to a comment allegedly made by the American Motorcyclist Association (AMA) that 99% of motorcyclists were law-abiding citizens, implying the last one percent were outlaws.