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 Students do not need to have strong phonics skills in order to engage in sound sorts. This can be a beginning phonemic awareness activity because students need only to identify the sound in order to complete the sort. Letter knowledge is not required, and phonemic development can mature as students do acquire more print knowledge. Picture sorts are one component of word study and are used to help beginning readers develop Concept of Word, phonological awareness, and phonics. Picture sorts most often begin with focusing on initial sound (single consonant, digraphs, or blends). By using picture sorts teachers are able