Thom is a British-born poet and academic who moves to the United States in the 1950s. He enthusiastically embraces the California counterculture, frequently riding his own Harley-Davidson in a leather jacket and tight jeans. Moving away from his formal British roots, he uses his personal freedom to explore existentialism and document the rebellious energy of his generation.

A group of young, energetic motorcyclists riding powerful machines across the California landscape. Clad uniformly in goggles and black leather jackets, they form a cohesive unit that transcends individual identity. They ride without a specific destination or preplanned route, relying on the forward momentum of their motorcycles to define their existence.

The contemplative narrative voice of the poem who watches the natural world and the approaching motorcyclists. The speaker observes the uncertainty of human existence compared to the instinct-driven animal kingdom. Seeking meaning in the chaotic noise and motion of the world, the speaker ultimately views the bikers' constant movement as a bold assertion of human will.

The morose leader of a motorcycle gang of about forty riders who disrupt small California towns. He rides a Triumph Thunderbird 6T and rebels against societal norms without a specific cause, acting as the quintessential anti-authority figure. His refusal to respect the local sheriffs or older citizens sparks mayhem.

An American student who meets Thom in 1952 while the poet is coming to terms with his identity. He becomes Thom's lifelong companion, sharing his life as the poet moves to the United States and builds his career in California.

A poet and literary critic at Stanford University in California. He serves as an academic instructor to Thom during the younger poet's graduate fellowship in 1954.

A prominent American actor whose portrayal of a biker gang leader sparks a massive cultural movement. His performance, complete with a motorcycle and leather jacket, directly influences a generation of young men who purchase similar gear to emulate him.

A prominent French philosopher who delivers a famous 1945 lecture outlining existentialist thought. His core idea that existence precedes essence provides the primary philosophical framework for understanding the motorcyclists' journey in the poem.