Bicycle handlebar a steep U-shape from the base, so that the rider's hands rest above waist-level. This style of bicycle handlebar became very popular in the 1960s after the introduction of wheelie bikes such as the Schwinn "Sting-Ray", Raleigh Chopper, and other highly stylized youth bicycles that imitated the appearance of drag-racing or chopper motorcycles of the day. Legislation in the United States introduced during the 1970s limited the maximum height of manufacturer-installed handlebars to 16 inches above the lowest seat setting; European Union safety regulations use a similar limit of 400mm. The apehanger style remained common in the US through the
Chopper (motorcycle) racing arena, which placed a premium on pure engine power, rather than handling over curvy courses. Chopper styling continued to be influenced by drag-bike modifications throughout the 1960s and 1970s. While all choppers are highly customized bikes, sometimes even being built from scratch using all custom parts, not all customized bikes are choppers. In Europe at roughly the same era that choppers were invented and popularized in the USA, bikers modified their bikes (primarily English brands like Triumph, BSA, Norton, and Matchless) in a different way, to achieve different looks, performance goals and riding position. The resulting bikes are known