Originally Posted by mtseymour

It annoys me to see another reference to this out-dated article with a misleading headline. If you actually read the article, you'll see that the brake failure was due to poor part selection, shoddy installation, and unsafe braking technique.

By the author's own admission, the "Braking was handled by a first gen TRP Parabox clamping on Ashima’s new and ridiculously light Ai2 rotors. It’s important to note that the original Parabox is meant as a cyclocross brake system. The rear caliper and brake pads are smaller than the front, and the Ashima rotors are about as minimalist as you can get. In other words, they’re perfect for ‘cross where speeds are low and braking is rarely a life or death matter."

It's such a bad idea to use 1st-generation cable-actuated disc brake with a "ridiculously" light rotor (designed for cross-country rides) on a "very curvy, steep road" at 30-40 mph. It's like using lightweight wheels and being surprised that they crack on a fully-loaded touring bike.

To compound the problem, the brakes were not properly installed. The Parabox is a clunky design that used two standard brake cables run from the road shifters to a pair of cylinder actuators on a hydraulic reservoir clamped to the steerer tube (under the stem). Exiting this unit are two hydraulic hoses that feed the calipers. By comparison, the current TRP Hy/Rd eliminated the hydraulic hoses by incorporating the hydraulic reservoir in the calipers. Since the Paradox used long hydraulic hoses, it's critical to properly bleed the fluid and eliminate air bubbles. Improper installation will make the brake fade badly ("the levers went to the bar"). The author installed the parts, cut the rear hose, and "chose to not use TRP’s stock rotors." He evidently didn't fully test the brakes before making a steep descent.

On top of these self-induced errors, the author used poor descending technique" "being my first time on this road, I kept light pressure on the levers, dragging my brakes to keep my speed around 30mph on a very curvy, steep road." The proper technique is to modulate the brakes (brake hard and release) using both the F & R calipers.

This article is really a cautionary tale about improperly using outdated technology. Even the author admitted that " I do not blame TRP or any other manufacturer for what happened. In hindsight, it was poor parts selection for the actual use. And perhaps I could have used better braking technique – brake hard, release, brake hard, release."

If you ignore this article, you'll get safe and powerful braking from modern designs like the Shimano R785, Shimano R9170 (with new flat mount), and Sram HRD disc brakes. Every top brand (Trek, Cannondale, Specialized, Pinarello, Cervelo, Giant, etc) now offer these disc brakes on their road bikes because they work really well. Caliper brakes are still a good choice if you value light weight and aerodynamics.