Derailleur gears a detent or ratchet mechanism which stops the gear lever, and hence the cable and the derailleur, after moving a specific distance with each press or pull. Indexed shifters require re-calibration when cables stretch and parts get damaged or swapped. On racing bicycles, 10-gear rear cassettes appeared in 2000, and 11-gear cassettes appeared in 2009. Most current mountain bicycles have either. Many modern, high-end mountain bikes have begun using entirely one chain ring drivetrains, with the industry constantly pushing the number of rear cogs up and up, as shown by SRAM's Eagle groupsets (1 by 12) and Rotor's recent 1
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