Several years ago, Shimano’s introduction of a dual-pivot standard reach (47-57mm) brake was well received as a tidy solution for wide(er) tires and lots of clearance. In practice, however, there were some small, but nagging, deficiencies. The quick release didn’t pass tires wider than about 28mm, and the maximum usable brake reach was really about 55mm.
Now comes the Tektro R538 caliper (above), which is a near-perfect implementation of this brake format. The novel long-throw quick release design is wonderful. When adjusted to work with a 19mm wide Mavic Open Pro rim, this release opens up the pads to a generous 33mm of wheel removal clearance. Wider rims yield an even wider opening. This makes a world of difference for users of Shimano brake levers. Couple the R538 caliper with a Campy-style release in the brake levers, and you’ll have clearance to remove any tire that you’d reasonably run underneath this brake.
As a frame builder, I’m excited about the fact that the R538 actually reaches to a full 57mm. I know this may sound a bit silly, but those extra 2mm are meaningful. On a carefully handcrafted frameset intended for standard-reach calipers, I’ll design to use every last millimeter of functional brake reach, and let the owner benefit from the maximum clearance. The photo above shows the R538 over a 700C x 32 Pasela.
I’ve used the Tektro R538 calipers on three bikes recently, and I find that the orbital washers behind the cartridge-style shoes make pad alignment a cinch. The brake’s high quality, graceful styling and lustrous finish compliment a beautiful frame. It’s now my "standard" for standard-reach calipers.
The frame pictured with the brake is Maggie’s new low-trail All-Rounder, built mostly with light weight Dedacciai Zero tubing. The lugs are Nuovo Richie, which are cast with the styling seen below. Once again, color was personal and important, and Maggie selected a gorgeous Medium Iris pearl.