Bill Harley and brothers Walter and Arthur Davidson found a motorcycle company in a shed behind the Davidson's home. But competition is fierce, and Walter has to put their fledgling business on the map by risking his life in racing competitions to beat the industry powerhouse, Indian Motorcycles. The rivalry between the two companies escalates with deadly consequences.

The Great Depression ravages America and cripples the motorcycle industry. With their company on the brink of ruin, Walter, Arthur, and Bill flout conventional wisdom by embarking on their most ambitious and expensive design yet.