Derailleur gears battery pack and to a small electric motor that drives the derailleur. Although expensive, an electronic system could save a racing cyclist time when changing gears. Derailleur gears Derailleur gears are a variable-ratio transmission system commonly used on bicycles, consisting of a chain, multiple sprockets of different sizes, and a mechanism to move the chain from one sprocket to another. Although referred to as "gears" in the bike world, these bicycle "gears" are technically "sprockets" since they drive or are driven by a chain, and are not driven by one another. Modern front and rear derailleurs typically consist of a
Word sort words. Spelling or word study notebooks may be used to record, collect, and organize information about words and spelling patterns learned from the word sort. To complement the many 'hands on' activities students use for sorting words, digitized word sorts provide an efficient way for teachers to deliver spelling pattern differentiation. A variety of these are ready-made, including wordsortwizard.com. Research has shown that students who experience significant difficulty with spelling follow the same developmental course as other students, but do so at a slower pace. In such cases, it is critical to provide word sort words at the appropriate developmental