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
English claims to the French throne French royal title, then the Flemish would be able to keep their honor, since they would not be attacking the "true King of France" (Edward III). Edward continued to use this title until the Treaty of Brétigny on 8 May 1360, when he abandoned his claims in return for substantial lands in France. After the resumption of hostilities between the English and the French in 1369, however, Edward resumed his claim and the title of King of France. His successors also used the title until the Treaty of Troyes on 21 May 1420, in which the English recognised Charles VI