Let’s start with a basic reality: disc brakes are coming to road and cross bikes, and hydraulic disc brakes are not far behind.
Fact 1: Disc brakes are coming to road and cross bikes.
Volagi is but one of the manufacturers who are toying with or outright building and selling disc brake equipped road bikes. They are certainly among the better known options out there, coming off of their recent bout of litigation with Specialized (where one defendant was ordered to pay $1.00 to Specialized. Way to go there, Speshy! That $1 verdict really justifies the amount you spent on legal fees in this case!)
Disc brakes are already in cross, and are now permitted in UCI races. There are a multitude of disc-friendly cross frames out in production…and even more cross-possible frames out there, such as my Vaytanium.
Frankly, they just make sense. With technological improvements, the weight penalty for disc brakes is dropping, rapidly. Disc brakes mean no need for brake reinforcement strips on rims. They mean no overheating of rims or delamination of carbon rims in downhill riding. No loss of braking power with ice/rain/snow. No aerodynamic compromises to create a braking surface on the rim. More stopping power and greater modulation. Folks–I’m not the only one thinking this. Disc brakes make sense for just about all bikes. Ok–maybe not TT bikes or extreme aero bikes intended for flatland road racing…where the aerodynamic advantages of integrated braking systems overcome the advantages of disc brakes. That brings us to point #2:
Fact #2: Hydraulic disc brakes are coming for drop bar bikes, and we should be excited.
Again–I’m not exactly cutting edge with the news that hydraulic disc brakes are around the corner for drop bar, STI bikes. Heck, full hydraulic groups may be around the corner. But why is that something to be excited about? In my mind, there are two primary reasons.
First, hydraulic fluid can be non-compressable, and can be run in hydraulic lines with minimal expansion/contraction. That means precise activation, no cable slop, no need to make adjustments over time to account for cable stretch. The feel can be more consistent. The difference here can already be seen in the feel of cable actuated disc brakes (e.g. Avid BB7) and hydraulic actuated disc brakes, on flat bar bikes. Even a clean, well-tuned set of BB7s has a hard time keeping up with a moderate set of hydraulic brakes.
Second, and perhaps more importantly, hydraulic brakes can have a much greater force/leverage/pressure advantage. That advantage can be translated either into more braking pressure, or more brake pad travel. And it can be done with cleverly designed hydraulic master cylinders that don’t take up significant amounts of space. (Sure, cable pull designs could have more leverage or more force, if you want huge, ungainly cable housings). Why is this important?
The MTB BB7s on my Big Dummy and Mukluk function perfectly…with flat bar, Avid SD-7 brake levers. They rarely need adjustment and they rarely malfunction. However, the Road BB7s on my Vaytanium have not had as distinguished of a service record. Why is that? Road BB7s are set up for use with STI controls. STI controls have a comparatively short cable throw, when compared to flat bar controls. Short cable throw means that, to achieve good braking force, the calipers must ramp up reaction quickly. That quick reaction ramp up design in the calipers means that the calipers are more prone to being out of adjustment. One millimeter of cable slack on the Dummy is relatively meaningless and imperceptible. (Heck–as long as the cable housings going to to the rear are, there’s undoubtedly more slack than that in the system). The Dummy overcomes that slack with the long throw of the SD-7s and a slower ramp-up/responsiveness in the brake calipers.
Road calipers don’t have that luxury. One millimeter of slack takes a perceptible amount of STI lever travel. That reduces braking effectiveness. That means that, for properly tuned brakes, you’re always chasing adjustments. Too loose, and you lack braking force. Too tight, and you drag the brakes. There’s no cushion in the system…so any imperfection in adjustment shows up in performance. And with cable based systems, unless you’re constantly chasing adjustment, there will be imperfection. If my SRAM Rival levers had more cable pull with the brake actuation, there would be less of an issue…but this isn’t SRAM specific…I’ve seen it on Shimano equipped bikes as well. And for that matter, wouldn’t one expect that SRAM would work perfectly with Avid?
A system that had no slack…no compressibility…that would be a perfect system. And that’s where the unique benefits of hydraulic come in. Less adjustment needed. More linear activation. More consistent feel. More resistance to accidentally being out of adjustment. Mo’ betta’ braking.
In addition, there are fewer unsealed, exposed moving parts with hydraulic brakes…which means fewer parts to get gunked up with mud/gravel/sand/slime in cross, gravel racing and touring riding.
Does the new world order of hydraulic disc brakes for road/cross bikes have downsides? Sure. Extreme-cold weather performance may suffer. Road bikes will take on the indignities of hydraulic brake setup and bleeding (in lieu of the much simpler, albeit more often repeated setup of cable systems). Potentially higher weight (remains to be seen). Greater cost and complexity. But those detriments will be worth it, I believe.
When they come, the Vaytanium will be an early adopter.