How To Adjust Bicycle Brakes And Derailers

By: Emily Weller

Break Studios Contributing Writer

Avoid having to go to the bike shop and save money by learning how to adjust bicycle brakes and derailers. Properly adjusted brakes help you to stop smoothly and prevent nasty crashes and accidents. You can't shift properly if your bike's derailer is loose or too tight. Put on your work clothes, grab a screwdriver and get to work making your bicycle ride as good as new.

To adjust bicycle brakes and derailers, you will need:

Your bicycle
Philips head (plus sign) screwdriver

Tighten the low gear limit stop screw. On the rear derailer of your bike, you will notice two screws about half an inch away from each other. The upper screw is the low gear limit and may be marked with the letter "L". Use the screwdriver to tighten this screw. You want to make the screw tight enough so that you cannot shift the bike into the lowest gear.
Loosen the low gear screw. After you've made the screw as tight as possible, slowly loosen it, a half turn at a time, until the bike is able to shift into the lowest gear again.
Repeat the process above with the high gear limit stop screw. Tighten the high gear screw (it may be marked with an "H") until you cannot shift into the highest gear. Then slowly loosen the screw until you can shift smoothly into high gear.
Place the bike in the highest gear to adjust the index shifter. Near the end of the derailer's cable, there should be a small barrel. Shift the bike into the next lowest gear and turn the barrel to tighten if it does not shift properly.
Press the brake handle for the front and back brakes. Inspect the way the brake pads grip the wheel rim. They should not touch the tire or dip below the level of the rim.
Adjust the brakes by loosening the adjusting barrel. The barrel is located near the brake at the end of the cable's housing (the plastic that covers the brake cable).
Loosen the bolt that holds the brake cable in place. Squeeze the brake handles to press the pads against the wheel's rim. Tug on the brake's cable until it is taut, then tighten the bolt.