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
Word sort - their spelling or orthography - the more efficient and fluent their reading will be. Word sorts place instructional emphasis on the exploration of patterns that can be detected in the sound, structure, and meaning features of words. Thus, word sorts contribute to orthographic or spelling knowledge, the engine that drives efficient reading as well as efficient writing. There are three different types of word sorts: sound sorts, picture sorts, and word sorts. Sound sorts can take on many forms in a primary classroom and this is essential because sound is the first layer of English orthography. Sound study can