TNT has a lightweight cantilever
Mechanical explanation of the TNT Canti. The arms are machined from 7075-T6 billet aluminum with a 10mm by 16mm rectangle milled away from the top section of each arm. A second 9mm by 13.5mm slot is milled for the pad holder assembly to fasten through the arm. The arm material is 3/8" (9.53mm) thick. The front of the lower section of each arm is rounded, reducing the weight of the corners. The rear of each arm has a 13.5mm wide half-round milling reducing the thickness at the middle of each arm to just 6mm. Each brake arm's internal tension spring is accessible, adjustable and replaceable. TNT machine presses a 1/2" (12.71mm) outer diameter, Black anodized aluminum tube through the arm at the base. This tube is 15.79mm long and its inner surface provides the pivot surface for the brake arm. There are three 2.35mm diameter holes drilled for the spring end to seat into. These holes are positioned at both side and the bottom of the pivot tube, 90 degrees apart.
A machined aluminum cap slides over the arm spring and encloses it. A hole in the cap allows the other spring end to pass through holding the spring in place. The top of the cap has two flat cuts spaced 13mm apart. With a 13mm cone wrench turning the cap one direction will increase spring pressure, the other direction backs off the spring pressure. Once the proper spring tension has been reached the mounting bolt is tightened to hold the spring and cap while allowing the arm to pivot freely. The brake pads are mounted on the front of the arm. TNT uses five pieces to hold and position the brake pad. The pad holder piece uses the "eyebolt" style used by many. The pad holder has a bulb shape which keeps the pad holding base washer in place even if there is no pad in the holder. It is machined from 7075-T6 rod stock, and Black anodized, making this the lightest pad holder on the market.
We found the SRP short shank, bulb shaped pad holder (our part # 06-91-PH) was an exact replacement for this aluminum one and the Titanium is a bit stronger though slightly heavier. The pad holding base washer behind the pad holder is machined of Titanium, while the convex washer at the rear is made from Black anodized aluminum. An aluminum flat washer is used to reduce friction while tightening the nut. The nut TNT chose is cadmium plated steel with 6mm by 1mm threads and has a 10mm outer hex shape. This 2 gram steel nut can be replaced with a 1 gram Titanium (our part # 06-91-010) for a 2 gram weight savings on already ridiculously light brake.
The TNT canti comes with two machined from 7075-T6 rod mounting bolts. They have a mushroom head with a 5mm fitting and 6mm by 1mm threads, a 12.5mm length and each weigh 2.25 grams. A Shimano straddle cable and Dia-compe cable carrier are included. The cable has a lead anchor on one side which fits into the top of the left arm. The top of the right arm has a 2.5mm diameter hole drilled through it, diagonally downward left to right. Another hole bored from the top is tapped with threads and filled by a metric cap screw. The other end of the straddle cable is pushed downward through the 2.5mm hole, a 2.5mm hex wrench tightens the cap screw and cinches the straddle cable. The cable carrier is stamped from sheet aluminum using two steel washers and a 9mm outer aluminum acorn nut to clamp the brake inner wire to the carrier. End of mechanical.
TNT ships their brake with Black Ritchey Logic brake pads. We found the TNT brake had a Bike-Pro brake profile measurement of 33mm. This cantilever can be used as either a front or a rear. The brake weighs 125 grams (remember 44.5 grams of this weight is the brake pads). To this add 4.5 grams for the mounting bolts and 8 grams for the cable carrier you have a total weight of 137.5 grams. The TNT brake is available with the arms anodized in Blue, Black, Green, Lavender, Red, Silver or Turquoise (light blue).
Color-B-BK-GN-L-R-S-T $ Price in Catalog