Kinda saw this episode coming. Matt and Trey spoke about this during commentary on an older season DVD. They were talking about how saying things like "don't be gay" or "don't be a fag" are just things you say to friends when they're being a jerk, not necessarily gay. And for the younger generations that appears to be true.
Regardless, I had a laugh at the bikers. My dad actually just inherited a bike that belonged to my late uncle. He use to ride when he was younger but now he's back into them. The bike is loud as hell too.