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.
The Shimano 105 brake set is a well engineered affordable brake set. It comes as calipers, levers, aero brake cable shrouds, and cables. These side-pull brake calipers use a dual pivot concept (which Shimano calls Super SLR) to keep them self-centering. By pinning the right arm of the brake it assures that the two arms will return to the same position. This style of brake mechanism increases the power multiplication factor which results in more braking power.
The calipers have a convenience adjuster and rotating cam quick release. The levers are aero style, with Black hoods. Available as short reach (39-49mm) or long reach (49-57mm). Weight for the brakes is 805 grams as a complete set (calipers-392 grams, levers-256 grams, and cables-157 grams with aero cable shroud). Specify reach.