Gear levers move the bike chain into the desired gear. The levers are connected to cables that run to the front and rear derailleurs on your bike. When a lever is pushed or pulled, the derailleur moves the chain up or down a cog. The left gear lever cycles through the front chain rings, while the right gear lever shifts through the rear cassette.
Expert bicycle mechanic Lennard Zinn identifies three types of shifting mechanisms for mountain bikes: the Rapid fire shifter, Thumb shifter, and Grip shift. The Rapid fire shifter uses two levers on each handlebar, one that you pull with your finger and another you push with your thumb. With a Thumb shifter, you use only the thumb to shift. A Grip shift is not technically a lever. You twist the handlebar grips of the mountain bike to shift gears.
The left and right gear levers function in different directions. On many mountain bikes, if you pull the left gear lever toward you, the chain will drop into an easier gear on the big chain ring. If you push the lever away from you, it will jump to a more difficult gear. This is opposite for the right gear lever. By pushing the right gear lever outward, it becomes easier to pedal. Pulling the gear lever toward you will make it harder.
Properly functioning gear levers make it easier for you as you negotiate the rough and varied terrain that is inherent to mountain biking. Easier gears mean less suffering on hills and more gears mean speedier descents.
Avoid adjusting your gears so that your chain is on the biggest ring in front and the biggest cog in back, or the smallest ring in front and the smallest cog in back. This chain position, known as cross-chaining, wears out components and is harmful to derailleurs, according to the George bicycle shop Bicycle South.
Article Written By Shane Farver
Shane Farver is a former newspaper reporter looking to immerse himself in freelance writing. Farver's interests lie particularly in writing about the outdoors and recreation, but he has a solid background of writing about politics, crime, and military issues. Being a former college instructor, he also enjoy writing pedagogical articles.