Monday, September 10, 2012

Road discs are coming...

Road discs are coming.  Just not on my road frames and I'll tell you why.  First, yes, road discs are coming.  Are they a good thing?  Sure, for certain applications.  Key phrase there.  Disc brakes make a ton of sense on bikes where your riding has miles and mile of descending with a lot of heavy braking and you:
A.  Ride in the rain
B.  Ride in the extreme heat
C.  Ride with carbon rims (clinchers or sew-ups, but especially clinchers)
D.  Are a big dude (or dudette)
E.  Ride the brakes down descents
F.  Want the latest thing
G.  All of the above

Now, I'm not down on road discs.  Really.  However, I think the bicycle industry has a lot of things coming out that are not necessarily consumer driven.  There's a lot that is being pushed out because bike and part manufacturers need to keep it new and fresh.  They rely on selling "new" bikes and parts year after year.  They are caught in a cycle that demands they create new bikes, parts, and niches. 

This cycle seems to be happening at an accelerated rate with more new stuff coming out than you can shake a stick at.  "Shake a stick at."  What the hell does that mean?  It's an all out war for bike companies to one-up one another in their effort to gain market share.  The piece of the pie isn't really growing so they have to make something that consumers want more than another companies something.  My widget is better than their widget and if you buy it, you'll be better/faster than your buddy who buys those other guy's widget.  

Okay, back to disc brakes.  They are coming on road bikes.  The good news is rim brakes will still be the overwhelming majority of brake options available on road bikes for quite a while.  I'm glad about this because I simply do not need disc brakes on my road bike.  At least, based on where I live.  Where I live, there are no stop lights.  There are only a handful of stop signs.  What there is is a lot of open road where I am not even touching the brakes for as long as an hour sometimes.  There are a few descents that require brake modulation, but there are also a lot of wide open, shortish, descents that can be taken at full speed, with no brakes.  Why would I need disc brakes for these types of rides?  I can ride out to the Pt. Reyes lighthouse and probably hit my brakes no more than 5 times in the 40 miles.  Your situations may vary.

One of the reasons I was skeptical about discs on road bikes was due to the tire's small contact patch and the power the disc brake offered.  My thought was that the power of the brake would over-power the traction of the tire.  Not the case as confirmed by a friend who shared my same concern and ended up on a vacation only able to ride the road on his disc brake mountain bike which he shod with road tires and had no problem controlling his speed.  

My biggest concern about road discs is the noise.  It's everyone's goal to have their mountain bike disc brakes run drag free, but we know that's not the case once the bike is out of the work stand.  Wheels, hubs, forks, stays, dropouts...all flex under load and when they flex, the rotor will touch the brake pads making that sound that is barely perceptible when combined with knobby tires in the dirt.  Now take that sound and put it on a road bike where things are much quieter.  How many times have you chased a tick or a click on your road bike that drives you crazy?  Now add in rotor scrape noise and that peaceful road ride is now fraught with unwelcome noise.  Your rotor heats up and warps slightly because you 'E' and you aren't going to be able to fix that out on the road so the rest of your ride is ridden with a 'ch, ch, ch' sound with each wheel revolution.  

On a road bike with rim brakes, if your wheel goes a bit out of true, you can reach down and without stopping either flip open the brake's qr or reduce cable tension with the barrel adjuster.  Brake rub sound goes away.  It's all good.  On a disc brake equipped bike, if your rim, er rotor, goes out of true, you've got nothing.  You might be able to back out the pads in the case of an Avid BB7 brake, but chances are, you'll be hearing that 'ch, ch, ch, ch, ch, ch...' the rest of your ride and it's going to drive you crazy.  And you're going to bring it to your mechanic and say "HELP!"  You'll get back on your bike and it will be quiet again until you get out of the saddle and rock back and forth up a hill and there's that sound again. 

So, road discs are coming and I have no plans in the immediate future to have disc brakes on my road frames.  Cross frames, however...  Ah hell, I'm still not personally in a tizzy to get disc brakes on my cross frames, but it's going to happen.  I just need to get more excited about them.

IMG_0002
Yes, this is an exageration, but the gap between pad and rotor is less than a business card.

IMG_0003
Ah, that's more like it.

One final thought on road discs:  I find it interesting that road discs are coming, yet there really are not any new disc brakes, or rather, new road disc technology coming out yet from the major component manufacturers.  I don't count what I would consider kludged together pieces to force the issue.  Road discs are coming with disc brakes that have been around for almost a decade.  Not bad technology, but one would think that while creating a new niche, manufacturers would want to introduce road disc bikes with new disc brakes, developed specifically for road use.  I think this points to bike manufacturers pushing road discs through the system without enough demand and a bit before manufacturers have a chance to supply disc brakes developed specifically for road use.

Post Script:  And as if on cue, this bit of news pops up regarding SRAM lightening their cable disc brake for road naming it the BB7 Road SL

(What's playing:  Dwight Yoakam Take Hold of My Hand)

11 comments:

Anonymous said...

It could be interesting to see 120 rotors and very small calipers, same size as the pads. Formula already working on it?

Adam said...

Your last paragraph really hit the nail on the head. Who cares if you can get an disc carbon road bike if you're stuck using BB7s!

I think you implied it, but I would add the weight penalty of discs as a draw back too.

This being said, I do need discs on my cross bike soon. In Fort Bragg, some of the downhills overpower my cantilevers. I'm waiting for the next generation of mechanical brakes to surface though.

blackmountaincycles said...

The problem with smaller parts is heat dissipation for lengthy descents that require considerable, heavy braking.

Anonymous said...

'not necessarily consumer driven' -yup. Carefully put.
I do not need to be so careful, as a cheap-assed consumer I offer you my unsolicited opinion; DUMB CRAP. That's a knuckle tat for you folks out there. I like how I can dig through an old box, pull out some mangled bits, and combine the old parts with a brand new part, and get a bike back on the road. Try that with disc systems, requiring proprietary FRAMES, HUBS, LEVERS, etc. But for those of you who like new cool stuff, please buy away, support great shops, and I will soon be scoring your old top notch equipment. Trickle-down at its best!

Guitar Ted said...

Regarding the last paragraph- I think the fact that nothing new in disc brake technology for road bikes is telling. To me it says- "We're testing the waters here, and if we see signs of life, we'll bring the goods." SRAM has said as much by teasing a hydro lever and telling certain folks behind closed doors about a much improved mech disc brake that's been on their drawing board for several years. But why bring out anything better if you don't know what the market will bear? Of course, Shimano will wait it out till the bitter end and then kill it with something so refined and R&D'ed to death it can't be made any better. But that won't happen unless the market shows some interest.

Interesting times, and this flat market is affecting other categories, (27.5 anyone?), and business tactics by the "big boys". Crazy stuff to be sure.

Chris said...

Good stuff Mike and the exact reason I sold my Salsa Vaya last year... No matter how much I fiddled, I couldn't get the sound to go away... Plus it was a bit of a pig... Now my XTR's on my mtn bike are just sweet...

Bike Zen said...

Then there is the elephant in the room..light weight carbon road forks have a hard enough time staying together without a rotor on the lever arm. I road a cross fork that nearly tore itself apart from the torque. I can't wait to ride a 15lb road bike with disks..that squeal will not be from the disks, it will be me screaming for my life

blackmountaincycles said...

And then there are also the carbon disc forks with 15mm thru axles. Probably wise because of all the crappy quick releases that seem to be the rule rather than the exception these days.

gypsybytrade said...

Road levers paired with BB7 Road calipers with full-length housing, as on the Vaya and Fargo, are uninspiring.

Cantilevers require some skill to set-up effectively, but the initial set-up of a disc brake, especially a mech disc, isn't much more accessible to consumers. Tuning rotors and caliper alignment is hard when "on the road" as a comfortable work space and good lighting help a lot.

My favorite brake combination has been the Shimano XT MC70 with Velo Orange brake pads, which has never left me looking for "more". However, the Tektro cantis that you feature are awesome.

Everyone hates the sounds of squealing, misaligned rotors, excusable only when the braking power is necessary. On a loaded fatbike, discs are the only way, but I still prefer cantilevers. Elsewhere, discs are overwhelmingly preferred.

blackmountaincycles said...

Compressionless housing works wonders on the Vaya or Fargo brake performance.

gypsybytrade said...

Ahh, good to know. Thanks