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
Glossary of French expressions in English in the original language, to the extent that they would not be understood (either at all, or in the intended sense) by a native French speaker. c'est la guerre: "That's war!", or... c'est la vie: "That's life!" or "Such is life!" Through the evolution of the language, many words and phrases are no longer used in modern French. Also there are expressions that, even though grammatically correct, do not have the same meaning in French as the English words derived from them. Some older word usages still appear in Quebec French. International authorities have adopted a number of words and