The hour record for bicycles is the record for the longest distance cycled in one hour on a bicycle. The first recorded hour record was in 1876 when F. L. Dodds rode 26.508 kilometres on a penny-farthing bicycle. Many people since then have tried to be the fastest. People trying to break the record have helped to change bicycle designs.
In 1972, the Belgian cyclist Eddy Merckx set a record of 49.431 kilometres. It was the record for twelve years. Since that time technology has allowed much more aerodynamic bicycle designs. The Union Cycliste Internationale (UCI), the group that controls the sport of cycling, has made rules to make cyclists ride cycles similar to Merckx's bicycle. Instead there is now another record, the International Human Powered Vehicle Association (IHVA) hour record, for other designs. The hour record for regular bicycles is called the UCI record.