Kasety
Cassettes for mountain bikes, road bikes, city and touring bikes
A matter of ratio. 11-speed, 10-speed, 9-speed, 8-speed and 7-speed cassettes
The cassette, often referred to as the sprocket is installed on the rear wheel hub and it establishes the link between the drive and wheel. The number of teeth determines how big the translation is, depending on the chain-rings. The more teeth there are on a gear, the smaller the transition. The fewer teeth there are, the greater the distance travelled per revolution of the crank.
Therefore, for city bikes, road bikes and mountain bikes, there are a wide variety of sprocket sets, which differ in size and gradation of gears. The decisive factor when purchasing cassettes is the number of gears, the matching chain and the right rear derailleur as well. The gradations of the sprockets and chains are now 1, 7, 8, 9, 10 and 11 fold.
If you want to play it safe, opt for one of the matching cassettes for the system that is installed on your bike.