Motorcycles are broken down into general categories. Off road, Track, Cruisers ( incl. Harley Davidsons, Kawasaki Vulcan, Yamaha Roadstar), Sport Touring (Honda ST1300), Touring (Honda Goldwing) and Sport.(Honda CBR600, Yamaha FZ6) Sport bikes are very fast highly mobile bikes where the rider is low and leaning forward. The bike is generally a cafe race style. A Crotch Rocket is the slang term for Motorcycles of the Sport category. The term is derived from their incredible speed. The previous definition of Non-Harleys is patently false. I have a Honda Goldwing and it is definitely not a Crotch rocket.