A motorcycle nerd. A person who is
obsessed with motorcycles, motorcycle culture,
gear, mechanical design, styling, etc. This person usually rides motorcycles extensively, has posters covering their walls, and bores others ad nauseam about
anything and everything pertaining to motorcycles. A subset of motorphilia.
Jim is a real motonerd. He rides his
bike 30,000 miles a year, has pictures of it on his
desk, and spends more time at
bike shows and riding than he does anything else.