A person who is fond of or has a fascination with armored fighting vehicles.

when cornrows go bad: the hairstyle worn by devotees begins to look less fierce and more like the balding treads on a fading car tire.

Someone who avidly enjoys watching Motocross. The term has also been used to describe "cheap seats" at Motocross events. ("Treadhead seats")

Getting head while running on a treadmill.