A mountain bike shifter is basically a component that helps regulate the gears in a mountain bike. The shifter works in either one of the two mechanisms; derailleur mode or the hub mode. Nowadays, the shifter only needs to make small changes to the gear in order to maintain a relatively steady speed. The front and the rear shifters help maintain the gears and ensure that it moves one at a time. This makes the gear shift either high or low. The shifter plays a key role in determining the particular position in which the derailleur will be.
Whenever, the shifter moves, the cables change and it determines the position of the respective derailleur. The movement of the derailleur is further facilitated by the movement of strong springs attached with them. The shifter actually moves these springs and makes the derailleur move to one particular side. Shifters are also capable of moving the cables to one particular side while riding. Shifters are a crucial component of all mountain bikes and they must be carefully replaced or maintained in order to ensure superior performance of the bike.