Note proper position of brake pad: entire pad face will strike the rim

Brake pads don't last forever. If you think they still look the same as when they were new, get a new one and compare. You will discover that new pads (most of them, anyway) have a kind of tread, that the rubber face (the part that strikes the rim) isn't shiny. The rubber should be tough, but not hard (hard pads cause squealing, and they do a poor job of stopping your bike). You can clean pads by scratching the faces with sandpaper (I've also used nail and metal files when in a pinch), but at some point the rubber will harden so much that even this won't improve its gripping power. Pop for new ones. And carry a replacement pair on multi-week tours in foreign lands.

Proper Rim Clearance

The following does not apply to"hub brakes" — coaster, disk, and drum brakes — which are more involved and will not be discussed here.

When the brakes are not applied there should be an equal distance on both sides of the rim between the rim wall and the brake pad. This distance should be between one eighth and three sixteenths of an inch (one to two mm), and, of course, a trued wheel is a necessity. Some riders, in an attempt to end the slapping of the rim against the pad, merely increase the distance between rim and pads when wheels go out of true and begin to wobble. This, however, is dangerous.

Exactly how to adjust the rim-to-pad distance differs with different brakes, but with all you will soon discover that you are exactly one hand shy of being able to do the job easily. So call a friend. Or purchase a "third-hand tool," which is enormously helpful in holding the pads against the rim when adjusting the brake cable length. With both hands free, you can use one to grip the cable and pull it taut, and the other to secure the cable anchor bolt. Close inspection behind the brake pad will show you the simple Allen-wrench adjustment that allows the pad to be pushed closer to the rim; just loosen the brake pad holding bolt and nut (this will be obvious) and slide the pad along the length of its metal rear shaft. Don't forget to tighten it securely once you've got everything just right.

Direct-pull or V-brake — a popular cantilever brake

Here's a tip if you have the popular direct-pull (Shimano V-) brakes on your mountain bike: Look for the tiny Phillips screws near the pads and turn them clockwise to pull the pad away from the rim, counterclockwise to push them closer.

Move on to Brake Alignment

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