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
Oxford-Hachette French Dictionary: French–English English–French Oxford-Hachette French Dictionary: French–English English–French The Oxford-Hachette French to English/English to French Dictionary is one of the most comprehensive and recent bilingual French–English/English–French dictionaries. It was the first such dictionary to be written using a computerized corpus and it contains 555,000 translations as well as 360,000 words and expressions. The work was first published in 1994, with its second, third and fourth editions appearing in 1997, 2001 and 2007 respectively. Though the dictionary is entirely bilingual, it is marketed under two different names, one for French, one for English: Its version is also available in a concise or condensed version.