Hydraulic Road Disc Brakes: Braking Update!

Sure enough, no sooner had I written more about braking options and ideas, I came across a few more choice tidbits.

First off, on the Fair Wheel Bikes blog, I saw this write-up of a newer hydraulic disc option – intended for MTB, but seems like it could be germane to the road situation as well. Rather than use tiny pistons (like current hydraulic calipers) this uses a system more akin to “bladders” or membranes to push the pads toward the rotor. The little red anodized line there keeps the two sides in balance with fluid, and the caliper body itself is apparently a single piece design. I feel like I saw another such system at some point, but can’t find it in my bookmarks file (by the way, I highly recommend Pinboard for bookmarking!). Anyway, the Fair Wheel guys note a more nuanced and modulated brake feel with these, even if they don’t provide the full-bore power of something like XTR Trail calipers.

photo via Fair Wheel Bikes.

These could be interesting, particularly for those who (wrongly, in my view) claim that hydraulic calipers are “too powerful” for the road context.

Secondly, I also came across a cool Canyon project bike from a couple of years ago….built around, you guessed it, hydraulic discs. Canyon’s approach was interesting, particularly for dealing with fork torsion loads. You’ll have to take a look at their site directly to see the one picture they’ve got up, but it’s worth the click. Canyon opted to go with a 2-rotor system up front. Yes, that means 2 calipers as well! This way rotors are very small and braking loads somewhat cancel each other out, it seems. Pretty impressive piece of engineering, although I’d like to see an update now that fork sizes have increased so much. Canyon came up with some kind of a shifting option integrated with the hydraulic levers, although it’s not clear from the picture what exactly their “fix” was; looks like extra levers of some sort.

Taking that Canyon Project bike from 2006 and adding the Fair Wheel Di2 hack…you’d basically be at the point of having a viable hydraulic disc road bike. Or, better yet, take the Volagi frame, add the Canyon dual-caliper fork, run Fair Wheel’s Di2 system, and you are there.

In the next installment, I’ll focus on fork design options…and eventually get to the ultimate goal: internal shifting.

bb

Hydraulic Road Disc Brakes: Shifting

As noted in the last post on this topic, hydraulic road disc brakes are foundational to the BB Road Bike of the Future. While no mainstream hydraulic road brifter has been brought to market (or any hydraulic road levers for that matter), I believe this hydraulic option can only be made more effective and useful if we also restructure the current shifting paradigm as well.

Shifting

Electronic. Fo’ shizzle. All the way. So, Shimano’s electronic Dura-Ace, Di2, kicks ass. This I’ve even tried out myself! One revelation about Di2, for me at least (but I actually heard the same from the guys at Above Category) is that the Di2 levers are by far the most comfortable and well-shaped of any levers currently out there. Some of that is probably chance, and your mileage may vary, of course. The revelatory aspect of this, however, is that electronic shifting removes one of the major design problems for current, all-mechanical shift/brake combo levers – no worries about shifting mechanicals! This is HUGE. No shifter guts in there (and the need to access them to change cables and housing) gives you a blank canvas for hydraulic actuation as well as ergonomic shaping of every sort.

Let me begin with an anecdote here, one that will demonstrate not only the clarity of my Future Vision, but also my hard-hitting journalistic chops. At the North American Handmade Bike Show in Richmond, VA last year, Shimano had brought Di2 test bikes mounted on wind trainers. They also had Shimano USA long-time tech honcho, Wayne Stetina, on hand to answer questions and pitch the product (and hand out Shimano word fridge magnets – 2 sets, new-in-bag – holla!). These satellite, button shifters had just been released:

With a relatively large crowd around, I asked Mr. Stetina:

“Could you use two pairs of these satellite buttons on their own, without the Di2 brifters?”

His reply, while almost laughing at me:

“Why would you want to do that?!”

Let me think. One reason might be that the Di2 brifters cost like ONE THOUSAND FUCKING DOLLARS and, like all brake/shift levers, are just waiting in one of the most vulnerable places on the bike to get either chewed up or completely busted any time you take a tumble. Moving to a button system – in which the button actuators aren’t particularly complicated or expensive – opens up many more options for shifter placement. For those of us who were around for Mavic’s first foray into the electronic shifting world, the Zap system worked in this basic way. You got a couple of shift buttons (and Chris Boardman later got a tiny little toggle switch for his chrono bikes) and nothing more. This also meant you could run Zap with whichever brake levers you wanted; in that sense, I always thought Zap had a really cool retro-tech duality as it allowed for old school brake levers and even a downtube front shift lever, if you wanted.

Reminder: singlepurpose components. Why – apart from the ergonomics of the whole thing – should your brake levers also be shift levers (or, more precisely, your ONLY shift levers)? Why can’t you shift with buttons that you place anywhere you like, including your brake levers, if you so please? Why does the “brain” for the shifting unit have to be located in the brake/shift lever as well?

Take out the shifter internals – in this case, the Di2 brain – and you should have plenty of space for hydraulic innards…and whatever shaping you want for ergonomics. Shimano has to “get” this, as they have already released another “satellite” shifting option for Di2, this one the so-called “sprinter” levers:

Clearly I am not the only one thinking along these lines, for the folks at FairWheel Bikes have brought a couple of show bikes out in the last year that leverage Di2 but, literally, hack the system in the service of some far-sighted ideas about the future of shifting. Reading their full documentation in their own words over on their own blog is a necessity, but I’ll emphasize some of the key points here.

The heart of Fairwheel’s project is a hacked and rebuilt Di2 controller module (brain). Here is the brain built-in to an Enve carbon stem:

photo via FairWheelBikes

This custom-built brain apparently allows for virtually any shifting patterns and rules to be sent to the derailleurs. In the case of these 29er MTBs, Fairwheel created a custom pattern that moves through the full range of the 2×10 drivetrain using only a SINGLE shift actuator. It does not do this merely by moving in a linear path from smallest to biggest – rather, it calculates a smooth progression of gear-inch shifts while avoiding cross-chaining as well as unnecessary front-ring shifts. Fairwheel says that it moves from smallest to largest available gears with only a single big-ring shift in there. Alternatively, the brain can be run in “manual” mode with the shift buttons running the rear derailleur; pushing both buttons moves the front derailleur using the logic of “other chainring”…which is fine, given that there are only two. The system can also “dump” gears (rather than moving gear by gear) – moving from highest to lowest in about 1 second!

The implications of this hacked Di2 brain are enormous…and get bigger the more you think it all through. Not only have you now removed the need for the brain to be housed in the levers, you have also opened up total flexibility in determining where you located shift actuators, how many you have, and how they work. If all you need is a simple actuator button to initiate shifts, why can’t you have little stick-on “buttons” or pressure points anywhere you want on your brake levers? Why not a fully enclosed, rubberized strip running the full length of the bars? Anywhere you would push would give you gear control (think of the yellow “next stop” strips running along the sides of busses).

In their own Di2 project bikes, Cannondale was already onto this idea, this time with the actuator buttons underneath some thin grips:

photo via Cyclingnews.com

Cannondale also got smart about repositioning the brain – even if they didn’t hack it to change the shifting operation:

photo via Cyclingnews.com

Finally, on the subject of cleaning up and integrating the guts of the electronic shifting system, Cyclingnews just today profiled a Vuelo Velo road machine that manages the Di2 battery by placing it on the end of the seatpost, using a system they say was created by CraigCalfee. This system is really cool and, presumably, makes it easy to run the power lines from the battery to the Di2 mechanisms in a fully integrated fashion:

So, there we’ve got the shifting taken care of…at least for now. As we will see, in the longer run I see electronic actuation being the norm – but without “external” gearing and derailleurs actually making the shifts. That, however, can wait for a future episode! And, before dealing with alternative gearing/shifting arrangements, let’s spend some time talking about fork and frame design – both of which are opened up to further system integration by hydraulic discs and electronic shifting. See you next time…

bb

Road Hydraulic Discs – When?

Having a number of high-end shops around here in NorCal, I’ve handled Shimano’s Di2 levers a number of times now (and tried them out in a ride-on demo at the NAHBS a few months back). Definitely my favorite lever feel of anything out there currently.

When I see and feel those levers, though, all I can think is that we are one step closer to a viable, top-end road hydraulic disc option. Looking at the 2011 XTR hydro levers, just drives this home for me:

After all, factor out the bar clamp and lever arm and you’ve got very, very little material left on these. And, assuming that the full extension of the hydraulic chamber there could be shortened a bit for a road application, seems like that could pretty easily be shoe-horned into the existing Di2 levers without much modification. Given how svelte the new XTR disc calipers are as well – and, again, factoring in the smaller size needed for a small-rotor road model – this doesn’t seem all that crazy, does it?

bb

via mountain.bike198.com.