Derailleur gears by 13 drive-train. Most road bicycles have two chainrings, and touring bicycles commonly have three. The rear derailleur serves double duty: moving the chain between rear sprockets and taking up chain slack caused by moving to a smaller sprocket at the rear or a smaller chainring by the front derailleur. In order to accomplish this second task, it is positioned in the path of the bottom, slack portion of chain. Sometimes the rear-derailleurs are re-purposed as chain tensioners for single-speed bicycles that cannot adjust chain tension by a different method. Although variations exist, as noted below, most rear derailleurs have
Influence of French on English chose to stay in England moved further away from France and, therefore, from the French language. Keeping its status as the language of justice and the language of power, England saw the first teaching manuals for teaching French to the English. These manuals were intended for English nobles who wish to perfect their knowledge of French and taught it to their children. Two types of French spoken in the higher spheres of English society could be distinguished during the thirteenth century : the Anglo-Norman dialect, which was the aristocrats' mother tongue, and a more prestigious type of French as a