Another issue that nattering naybobs of negativity bring up is that disc brakes add weight and increase drag, which has some validity. Yes, disc brakes definitely add some weight (about ¾ pound more than a Dura-Ace caliper system), but with disc brakes you’re able to shave weight in perhaps the most important place on a bicycle – the outer portion of the wheel where the rotating mass is.
Rims that used to require a heavy brake surface track can be eliminated, and more aerodynamic designs can be used. As disc brake technology on road bikes becomes more developed, naturally the weight of a disc system will continue to come down. And with the millions of dollars that bike brands spend in wind tunnel testing, drag will also be reduced as disc brakes become the norm.
Better braking safety, control and modulation in all-weather conditions, the ability to use lighter, stronger carbon wheels without braking tracks, effortless one finger braking power without sudden lockup and better clearance to run bigger tires; they’re all reasons why you should be riding a disc brake road bike.
What’s available now?
So you’re sold on disc brakes, now you’re probably wondering what the options are. Well, forget about cable-actuated disc brakes. It’s akin to running drum brakes on a Ferrari. At Interbike this year, I was dumbfounded by the number of high-zoot, ultra-super-duper high modulus, custom molded, limited edition Formula 1 Torayca carbon fiber frames with next generation electronic shifting systems and bank account busting carbon fiber wheels only to find them equipped with prehistoric Avid BB7 cable-actuated disc brakes you can find on a $700 commuter bike. Huh?
From a hydraulic perspective, there are really only two viable options at this point, both of which are cable to hydraulic adapter systems, allowing you to run any cable pull lever with a hydraulic mountain bike disc brake unit.
TRP makes a contraption called the Parabox, which mounts the master cylinders off the fork steerer tube underneath the stem. I’ve ridden this system, and in all honesty, I was underwhelmed. The whole point of hydraulic is to have smooth lever actuation and terrific modulation, neither of which the Parabox has. There are simply too many bends in the cable part of the system, giving the rear brake feel that same notchy sensation as a poorly set-up cable operated caliper.
The other much simpler, cleaner and superior functioning solution comes from 324 Labs. They make mounts that work with the lightest mountain bike disc brake system on the market, the Formula R1. The 324 Labs system works because the cable is no more than a foot long, and is as direct of a pull as possible. The result is a system that feels exactly the same as the Formula R1 mountain bike lever; incredible modulation, no notchy cable pull feel and the absolute lightest hydraulic disc brake setup available, with only an eight gram total mass gain over the standard Formula R1 mountain bike setup. The best part is, even as Shimano and SRAM eventually come out with their own dedicated hydraulic system, the 324 Labs setup allows you to run any existing cable brake lever, regardless of brand.
The hydraulic disc road bike wave is about to come tumbling upon us. Shimano and SRAM are leaking photos of their dedicated systems, Colnago released the C59 with a proprietary hydraulic road unit developed by Formula, and Volagi – the sole manufacturer that designs only disc brake road bikes – had a line of gawkers a mile long at Interbike. So if you’re in the market for a new road bike, get ahead of the curve and start looking at frames with disc brake mounts and 135 millimeter rear hub spacing. Because within a couple years, caliper brakes will be a museum novelty like Biopace and downtube shifters.