Bicycle:Penny Farthing

Early bikes, called a penny farthing, high wheel, high wheeler, or ordinary, sported large front wheels as makers realized that the larger wheel moved the bike a greater distance on single revolution or push of the pedal. But the high-wheeled bicycle had one big problem: when the front wheel stopped, the entire apparatus rotated forward on the front axle, propelling the rider over the wheel and landing him on his head, which explains the term "taking a header."