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.

Walter and Bill convince Arthur that Harley-Davidson must rejoin the racing community if their business is to survive. Distracted by their race to the top, the founders of Harley-Davidson leave themselves vulnerable to a devastating and unforeseen threat to the survival of their company.

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.