- California Doubling: The show is set in and around Wisconsin, but was filmed in Romania both for budget and artistic reasons.
- Cast the Expert: Both Bug Hall and Michiel Huisman are motorcycle enthusiasts, though for the more dangerous stunts like the Motordrome race they obviously had to rely on stunt doubles.
- Fake American: British Robert Aramayo and Dutch Michiel Huisman, who portrayed Bill Harley and Walter Davidson respectively. Interestingly enough, Aramayo's character is the son of English immigrants who moved to the States in the 1860s.
- Shown Their Work: The producers took the effort of having reproductions of period-era bikes made just for the show using the original blueprints, which is in contrast to Indiana Jones and the Kingdom of the Crystal Skull where they halfheartedly dressed up a 2007 Softail Springer to make it appear older. The head of the Harley-Davidson Museum at Milwaukee and one of the founders' grandchildren remarked at how they "did the homework" with bringing the story to life, though they did note about William Davidson's reduced role in the drama.
- Joe Harley's condition was actually based on historical fact: a series of letters show that Joseph W. Harley served in the Philippine-American War as part of the 69th Co. U. S. Coast Artillery Corps from 1902 to 1903, and his experiences in Negros Island were harrowing, leaving Joe a "nervous wreck". This led to William pulling some strings for the US Government to better look into the welfare of shell-shocked veterans like his brother.
Trivia / Harley and the Davidsons