The rear derailleur is responsible for the quality of the shifting like no other component. Even more important for the reliable and trouble-free gear change than the name of the manufacturer are the individual components, such as shifter, rear derailleur, sprockets and chain, are matched and suitable for the same number of gears. By operating the shift lever, the rear derailleur adjusts the chain to the required gear ratio by pressing or pulling it. When choosing your rear derailleur, in addition to the consistent number of gears, 6, 7, 8, 9, 10 or 11-speed, you should also consider the field of application, because the used components differ between road racing bike, trekking bicycles and mountain bikes.
