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 states like New-Brunswick, Quebec, Ivory Coast, Benin, Togo, Guinea, Cameroon, Congo, Democratic Republic of the Congo, Madagascar, Mauritius, Tchad, Djibouti, Senegal, Morocco, Algeria, Tunisia, Lebanon, France, Belgium, Switzerland, Luxembourg, Monaco, Aosta Valley, French Polynesia, New Caledonia, and Vanuatu adopting it as their official language. This geographical diversity has led to many different contacts with vernacular dialects, regional and international languages, from which French has often been enriched locally. In a number of countries and regions where French shares co-officiality with English (Cameroon, Canada, Jersey, Mauritius, Rwanda, Vanuatu), particular lexical regionalisms are observed where French and English terms are used interchangeably.