Harness racing use a standing start. The sulky (informally known as a "bike") is a light, two-wheeled cart equipped with bicycle wheels. The driver (not a "jockey", as in thoroughbred racing) carries a light whip chiefly used to signal the horse by tapping and to make noise by striking the sulky shaft. There are strict rules as to how and how much the whip may be used; in some jurisdictions (like Norway), whips are forbidden. For exercising or training, the drivers use what is known as a "jog cart," which is a sulky that is heavier and bulkier than a racing unit.
Horses in the Middle Ages and archaeological evidence suggests that they were stout but short, approximately , and capable of drawing a load of per horse. Four-wheeled wagons and two-wheeled carts were more common in towns, such as London and, depending on type of vehicle and weight of the load, were usually pulled by teams of two, three, or four horses harnessed in tandem. Starting in the 12th century, in England the use of oxen to pull carts was gradually superseded by the use of horses, a process that extended through the 13th century. This change came because horse-drawn transport moved goods quicker and over