Motorcycle speedway
Motorcycle sport
Motorcycle speedway, usually referred to simply as speedway, is a motorcycle sport, a variety of track racing, involving four and sometimes up to six riders competing over four anti-clockwise laps of an oval circuit. The motorcycles are specialist machines that use only one gear and have no brakes. Racing takes place on a flat oval track usually consisting of dirt, loosely packed shale, or crushed rock (mostly used in Australia and New Zealand).
From Wikipedia, under CC BY-SA. More on occurri.