Derailleur gears operates the lever while pedalling, the change in cable tension moves the chain-guide from side to side, "derailing" the chain onto different sprockets. For more information about the choice of particular gear ratios and sprocket sizes, see Bicycle gearing. "Derailleur" is a French word, spelled "dérailleur" in French, derived from the derailment of a train from its tracks. Its first recorded use was 1930. At least one notable bicycle industry author has attempted to promote the anglicized spelling of "derailer". As of 2013, however, neither Merriam-Webster nor the Oxford English Dictionary has an entry for "derailer". Various derailleur systems were
Influence of French on English the century, to Henri VI and Marguerite in the 15th century, all kings of England married French princesses. These marriages made French the language of the English court for several centuries and were decisive in strengthening the use of French in England. This period (12th-15th centuries) is characterized by a massive influx of French words into Old English vocabulary. In 1204, under Philippe Auguste, Normandy was officially annexed to the Capetian royal demesne (previously, Normandy, though part of French kingdom, was largely autonomous, under the authority of its dukes, kings of England), politically isolating England from the continent. Normans who