How do the front and rear deraillers work on a bicycle for shifting?

Question

Does one slow you down and one speed you faster?

I guess I am asking why is there a shifter on the left and why one on the right? Is it for right handed or left handed people?

Answer 1

May I suggest that you visit your local bicycle shop and sign up for a basic bicycling class? You sound like a new rider. As basically as I can, I'll try to answer your question. The shifter on the right works for the back gears. The shifter on the left works for the front gears. There is a most efficient pedal rotation speed suited to you (it's different for everyone). The combination of front and rear gears allow you to maintain basically the same pedal rotational speed regardless of the terrain (within certain limits). The smaller the front gear you use, the easier it is to pedal (especially uphill) and the faster your pedals will go around. The smaller the rear gear you use, the slower the pedals will go around. You will find that for uphills, flat roads, and downhills you will find generally three gear combinations that you prefer based on your riding style. Trial and error is the best teacher. Change the front and rear gears until your pedal speed and effort feel right for the type of terrain you are on.

Answer 2

As the name implies, you actually de rail the chain from the sprocket that was riding on. A cable attached to either derailier, at one end, and a shifter at the other. By clicking your shifter/twisting your grip or pulling the gear lever, you pull the derailier left or right. This causes the chain to jump from one sprocket to the next, changing gear. Same princinple works for front or rear.

Sounds simple and it is, until you try to set the damn things up.

The smaller the gear, the easier it is to peddle, but will slow you down - hills. The bigger the gear, the faster, but harder to peddle.
Luck

Answer 3

the chain runs through each of these components. there is a spring inside, and when you click down on the shifters, the cable tension is released slightly, and the spring pulls the derailleur in enough to drop the chain on the next closest gear. when you click up, you are pulling the cable and working against the spring, which is why one direction is harder to shift than the other.