SHIMANO "DUAL PIVOT" SIDE-PULL BRAKES - An Overview

In Shimano's Dura-Ace, Ultegra, and 105 SC series brakes, there exists a "Dual Pivot Brake". It's a side-pull brake. These brakes have three arms that form the caliper. The arm nearest the bike (1) which is held in place by the pivot bolt serves as a mounting for the arm farthest from the bike (3). Between these two is another arm (2) held in place by the pivot bolt. Arm 2 works just the way the short pivot arm has always worked. Arm 3, holding the brake pad, has a pivot bolt half way between the traditional brake and the brake pad, which is fixed to arm 1. Using the dual pivot system Shimano has shortened the travel on the long arm. The brakes respond faster, remain centered, and require fewer adjustments.