BMX

In the early 1970s, when teenagers imitated their motocross heroes on their bicycles, BMX bikes, specially designed bicycles that usually have 16 to 24-inch wheels (the norm being the 20-inch wheel), were originated in the state of California. The 1971 motorcycle racing documentary, On Any Sunday, is generally credited with inspiring the movement nationally in the U.S., as in the opening scene, kids are shown riding their Schwinn Sting-Rays off-road.