Just how important are road disc brakes?
Few subjects have inspired more debate at this year’s first three days of the bike test than road disc brakes. What are the benefits over rim brakes? Are they worth the weight penalty? Is any brand doing them right? And, simply, do we even need them?
Of the 30 bikes we’re testing, six are equipped with discs, including the Pinarello Dogma 65.1 Hydro ($5,600 frame set). More manufacturers intended to send disc brake-equipped models, but with the SRAM recall of their Hydro 22 brakes late last year and Shimano's slow delivery of their new Ultegra R785 Hydraulics, the demand was higher than the supply.
The Dogma, like three of the six bikes with discs in the review, is equipped with TRP’s HY/RD, which use mechanical levers and cable actuation to control the hydraulics in the caliper. Of all three brands, these are the least expensive ($150 per wheel) and have worked flawlessly throughout our testing.
The consensus, even among the staunchest hydraulics skeptics, is that these brakes bring impressive stopping power and finesse. Everyone agrees on the benefits of separating the braking force from the rim, especially on carbon where the heat from braking has caused wheel failure in certain cases. Whether or not it’s worth the weight penalty—our Dogma tips the scales at 17.6 pounds—is an ongoing dialogue.
But the Dogma is more than disc brakes. This, of course, is the same frame that Team Sky rode at the spring classics last year and the one that Chris Froome will likely ride when the Tour hits the cobbles in 2014 (minus the disc brakes). It’s built from Pinarello’s top-shelf Torayca 65-ton 65HM1K Nano-alloy carbon fibre, and smaller side to side differences than before, despite retaining the company’s trademark asymmetric design.
The Onda fork's characteristic waves are also toned down, and the non-drive-side chainstays have post mounts and extra reinforcement to accomodate the added force generated by the disc brakes. We equipped ours with Vision aluminum wheels mounted to 28mm Continental Grand Prix 4000 tires, a natural combo for endurance racing and rough surfaces such as cobbles—or Tuscon's beat-up asphalt. It’s also spec’d with Shimano Dura Ace Di2 components.
After finishing the full-fledged race bikes yesterday, I took my final lap aboard the Dogma and was floored by just how comfy and stable it was. The aches in my back and sting in my shoulders and neck that developed from two hard days of riding were nearly unnoticeable aboard this cushy bike. Even after 60-plus miles, and with a fifth run up the 500-foot climb of the west side of Gates Pass ahead, the Dogma's comfort far outweighed its extra weight. I ripped down the screaming descent back to the truck with exceptional confidence, thanks to the bike’s stability and the sureness of the disc brakes.