Watched this as my dad used to own a Harley-Davidson Sportster, and partly as I got into period dramas no thanks to my American Girl collection, but I digress. Aramayo, Huisman and company did deliver something decent to the table, but my biggest beef was that while racing was a part of the company from the get-go, it seems to be given too much of an emphasis, and yet Big Bill Davidson was, in TV Tropes parlance, demoted to an extra even though he is a key founder in his own right.
I do understand that the racing subplots, and the Davidson brothers' alcohol-fueled fists of fury were weaved in for dramatic effect, but maybe the producers could've balanced it even more. Also, the original 1936 OHV wasn't referred to by the founders as the Knucklehead early on; it wasn't until the 60s where bikers referred to the engines by the shape of the valve covers, and the founders wouldn't certainly be up to presenting a Knucklehead prototype in front of outlaw racers.