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 will for most students lead to the abstraction of spelling patterns and the sounds to which they correspond. Word sorts can be teacher directed (closed) or student directed (open). For example, students in the with-in-word pattern phase of word knowledge could sort words according to a vowel pattern; in such sorts there is always a miscellaneous category for words that do not follow the target categories. Game-like formats such as board games and card games can also be effective if they focus on words that reflect spelling patterns. Word-building activities also facilitate abstraction of pattern: word wheels, flip charts, making