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 among the clergy. French was therefore, at first, spoken in England under the form of this Anglo-Norman dialect. During the 12th century, continental French had a greater influence on Old English. It acquired great prestige in England, especially within the aristocracy and the clergy. It became the language of law and justice nationwide. Rich and noble families, most of them of Norman origin, taught their children French or sent them to study in France. The expansion of the French language in England was also encouraged by royal marriages. From Henry II Plantagenet and Eleanor of Aquitaine at the beginning of