Sorting Brake Calipers

There are two steps to sorting brakes. First, separate the two main types of brakes.

Caliper vs. Cantilever vs. V-brake

Calipers

V-Brakes Front

V-Brakes Back

Caliper and Cantilever brakes attach to the bike differently. Caliper brakes attach above the wheel, and have a long bolt coming out of them. Cantilever and V-brakes attach next to the wheel, and are in two pieces. It's not hard to tell the difference, as you can see from these pictures: two types of caliper brake above (center-pull type to the left, side-pull to the right), and a V-brake brake below. A cantilever is similar to a V-brake in that it attaches to the same mounting studs, but it uses a straddle cable to pull the arms together instead of running the brake cable across the two arms.

Usually when you sort brakes they have the pads on, so caliper brakes will be one piece with two pads, and cantilever and V-brakes will be separate pieces with one pad each.

Sorting Caliper Brakes

The brake on the left is a centerpull. They are always the same on both sides, and usually have a cable running across the top like this one does. The brake on the right is a sidepull. They always have two things above each other on one side (the right side on this brake), and a bolt in the middle. Centerpulls have a bolt in the middle, but you can't see it from the front.

There are two types of caliper brakes, shown in the picture below.