A Rat bike is any motorcycle in good to a crappy condition that you don’t really care about. That said, some people care plenty about their rat bikes. But for the most part, rat bikes are machines for just gettin’ around and if it gets crashed, tipped over, snowed on, or some drunk idiot pukes on it, oh well, hose it off and it’s good to go. Be sure to own at least one rat Bike in your riding career.