People are rarely angry for what they seem angry about, its likely something else that's bothering him and the bike was a convenient escape for that anger. I'm sure he has lots of internal chaos going on and things he needs to work out so these events will happen. Chances to validate his feelings about stupid things, even if they are stupid, might help him open up to whats actually going on in his head/heart. Maybe tomorrow he will be pissed at the toaster for making his bread hot, who knows.

Just go into the MC with an open mind and try not to take anything personal.

Accept what is, let go of what was, and have faith in what will be