ROAD BIKE MAINTENANCE: Caliper Brakes
If you have a modern road bike it's more than likely you have dual-pivot caliper brakes. These brakes give better and more aggressive stopping power than the single-pivot caliper brakes found on older bikes. They are also much easier to adjust and keep the brake pads an equal distance from each side of the rims which increases wear and improves efficiency.
Inspecting and maintaining brake calipers is very easy to do. All you need is a good set of Allen wrenches. You should regularly check brake pad wear, alignment of the pads on the wheel rims, whether both pads are coming in contact to the braking surface simultaneously, and brake travel.
Periodically inspect brake pads for wear. If the pads have worn unevenly or more than half their original depth, it is time for replacement. To replace the pad, remove brake pad retainer with an Allen wrench as shown. Slide the pad out. Slide a new pad in and tighten the retainer. If the pad and shoe is one complete unit, replace the entire piece.
Align brake pads with braking surface. Brake pads must be carefully aligned with the braking surface on the wheel rim. If they are too high they can damage the tire. If they are too low, they will wear unevenly. To align brake pads, loosen the 5 mm Allen bolt on the pad. Align the pad with the braking surface. Retighten the Allen bolt.
Centering the brakes. The brake pads must come in contact with the braking surface simultaneously. Check this by gently pulling the brake lever until one or both of the pads touches the braking surface. If they do not touch at the same time, they can be easily adjusted by simply turning the adjustment screw which is located on the caliper. While gently squeezing the brake lever in and out, turn the screw each direction as necessary until the pads are centered.
Adjusting brake lever travel. The distance you pull the brake lever in is really a personal preference. However, we generally recommend a distance of half way to the handlebar. If you have to pull the brakes in too far toward the handlebar you can adjust it using the following procedure.
First, loosen the Cable Pinch Bolt just so the cable can slide through without restriction.
Next, squeeze both sides of the caliper until the pads are nearly touching the rim. As you do this the brake cable will slide through the fixing bolt. Tighten the fixing bolt securely against the cable and release the caliper.
Minor adjustments can then be made to move the brake shoes in or out as necessary which also modifies the brake lever travel. This is done by turning the barrel adjuster. Turn it clockwise and counterclockwise until the brake lever travel is about half the distance to the handlebar.
Quick-release mechanism. Shimano brakes have a feature which allows you to easily remove your wheel without making any permanent brake adjustments. Simply move the quick-release mechanism to the upright position and your brakes will spread out enough that you will be able to remove your wheel. After you replace the wheel be sure to move the quick-release mechanism back into the closed position.