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
Quebec French lexicon examples of long-standing Anglicisms include: It is also very commonplace for an English word to be used as a nonce word, for example when the speaker temporarily cannot remember the French word. This is particularly common with technical words; indeed, years ago before technical documentation began to be printed in French in Quebec, an English word might be the most common way for a French-speaking mechanic or other technical worker to refer to the mechanisms he or she had to deal with. It is often difficult or impossible to distinguish between such a nonce Anglicism and an English word quoted