Modern motorcycles are engineered with clinical precision that sometimes makes even fire-breathing superbikes seem relatively sober. Happily, the veneer of civility fades away when a big handful of throttle or a perfectly slipped clutch sends the front wheel skyward. With the right wrist, any bike can be a wheelie monster, but some bikes have hooliganism in their DNA. These are the bikes your mother warned you about, the bikes whose wide bars jeer at you from the darkened corner of the garage, the bikes that encourage behavior frowned upon in polite company. These are five of our favorite wheelie bikes currently on the market.