Motor-paced racing and motor-paced cycling refer to cycling behind a pacer in a car or more usually on a motorcycle. The cyclist (or stayer in this case) follows as close as they can to benefit from the slipstream of their pacer. The first paced races were behind other cyclists, sometimes as many as five riders on the same tandem. Bordeaux-Paris and record attempts have been ridden behind cars. More usually races or training are behind motorcycles.

Cyclists started to use tandem bicycles as pacers in the late 19th century. There could be as many as five riders on the pacing machine. Because of the long distances covered when following a pacer, these cyclists were called stayers, a term used in long-distance horse racing. Companies such as Dunlop sponsored pacing teams, and "tens of thousands" turned out to watch. A south London rider, J. W. Stocks, set British record of 32 miles 1,086 yards (52.492 km) in an hour behind a Dunlop quintuplet on 27 September 1897. The pacing tandems were ridden by professionals, of whom as many as 100 were under contract. Each competitor had six to eight pacing teams for races between 50 and 100 miles (80 and 160 km).

Speeds rose when engines were added to pacing tandems. Arthur Chase and the Frenchman Émile Bouhours set English records behind powered tandems in 1898 and 1899. Chase used a 4+1⁄2 bhp (4.6 PS) motorcycle to pace him to 37 miles 196 yards (59.725 km) in a private test at The Crystal Palace, south London, in July 1900 but riders in the USA and in Paris had already done better. Some races mixed pacing with solo bicycles, tandem and motorcycle, with the riders given different start points in compensation.

Bordeaux–Paris, a race of nearly 600 km (370 mi) from south-west France to the capital, was paced part of the way by cars in 1897, 1898 and 1899. So was Paris–Roubaix. The historian Pierre Chany said: "Cars made only a brief appearance in Paris–Roubaix. On the roads of the north, these noisy cars, high with wooden wheels with their tires nailed in place, raised huge clouds of dust. The drivers, wearing leathers, their eyes protected by huge goggles, were stepping into the unknown! The riders hidden in all this chaos could see absolutely nothing and risked their life at 50 km/h (31 mph) on the edge of a razor. The noise was infernal and the column advanced in the stink of exhaust pipes."

The first races were limited more by the speed a motorcycle could achieve than the ability of the rider to follow, with 50 km/h (31 mph) being a good average, according to the historian H. M. Ellis. The races became faster as the pacers became faster. Paced races kept audiences enthralled for many decades in Europe and, at one time, in North America. Tens of thousands watched, especially in Germany. The popularity of this form of pacing declined in the latter part of the 20th century.^{[citation needed]}

There were few rules. Pacing machines had small rollers set sideways behind the back wheel to avoid crashes caused by the rider touching the back of the motorcycle, but there were few other regulations. Race distances extended to six days, although one-hour and 100-mile (160 km) contests were more common. Windshields were briefly allowed but abandoned after the world championship in 1904.

Speeds rose and accidents became commonplace. An American, Harry Elkes, died of his injuries from a crash in front of 10 000 spectators at Boston, Massachusetts, USA. His rear tire exploded at 100 km/h (62 mph) and he was thrown under another rider's pacing machine, which "crushed the prostrate man in a dreadful manner." George Leander of Chicago said, "Only the clumsy get themselves killed" before starting a race at the Parc des Princes in Paris. Leander was thrown five metres (16 ft) into the air after 80 km (50 mi), fell to the track, bounced into the seating and died 36 hours later. A crash in Berlin on 18 July 1909 killed nine when a motorcycle careened into the stands and exploded.

The historian Peter Nye wrote: