7/13/14 5:28 AM

I get it, better stopping power in the wet. But do we really need it? The tire's traction is already the limit of the system.

The disk brake system is aero dirty to say the least.

Weighs more than standard rim brakes.

Prevents fast wheel changes.

Is stupid expensive.

Has marginal performance gains if any for stopping the bike and rider in normal conditions.

Is overly complicated.


Rim brakes are technically disk brakes folks. A good set of brakes/pads/rim stop so well you can easily endo on your nugget. You can do that with cheap set up too.

I see disk brakes on a road bike as an answer to a non-problem.

I am all for electric shifting, integrated two post designs, etc. I just don't see a technical advantage to disk brakes on a road bike. None.

C-Cross, damn straight, MTB of course. Road racing or riding? Nope, they are a waste of $$$$$.

7/13/14 5:43 AM

IMO no need whatsoever, aside from increasing corporate profits.

"I see disk brakes on a road bike as an answer to a non-problem. "

truth. see "corporate profits" above.

7/13/14 6:06 AM

I tend to agree, but there might be real benefits for lighter carbon clincher rims.

7/13/14 6:17 AM

Plus they are touchy to set up and maintain and when they start to screech it's intolerable and a PITA to fix. I have them on my commuting bike, but actually I'd prefer cantis.

7/13/14 6:46 AM

Lighter clincher rims? Not at the other expenses. The braking surface is not the limit on the carbon clinchers (compound/friction issues excluded). The limit is the sidewall strength required to hold the tire securely. Carbon in it's current form is at the limit, put some calipers on any set of rims, Al or C and measure the width before and after inflating the tire. They spread, and any lighter they would give up the ghost on many carbon clinchers.

The UCI needs to drop the min. weight limit, go unlimited as long as they are production frames that are available in at least 3 sizes and the manufacture makes at least 2000 units with no more than half of the frames going to their sponsored teams. All must pass the UCI strength test.

I would love to see sub 4 kilo bikes all over the peloton, even if I can't afford one. There would plenty of trickle down benefits for all of us.

Canti's are the way to go IMO. VERY light, simple and can be very aero. Some top shelf frames are going to them now. The new Look forks even have them in the fork leg itself. Though, I wrenched a set a few weeks back and what a PITA to set up!!!

7/13/14 6:59 AM

in the motorcycle world, us manufacturer Buell has actually gone away from traditional dual hub-mounted disc rotors and instead uses a single perimeter-mounted rotor.

a single rotor in this design offers comparable braking power to a dual-disc setup at a lower weight. conceptually moving *toward* a rim-brake on a bicycle.

industry wise, this is an outlier...theres so much investment in the traditional design approach to moto brakes, this will always be a niche approach.



Last edited by walter on 7/13/14 7:05 AM; edited 1 time in total

7/13/14 7:00 AM

"new Look forks even have them in the fork leg "

CX forks ?


The front bake on my X9 was it strongest point and the best MC brake I have ridden. Mostly pinky actuation, and two fingers when you got serious. And a lot more metal for heat dissipation. Set up makes nothing but sense to me.

Giving up a 700C Disk for a 6" one make no sense to me. Except wet use I guess. And I dislike the dual rear wind up/down on the wheel personally. I guess i could have gotten use to the fell of that though.

Used BB7 and CX-55 setup so far. I think the BB7 is a nice cost effective setup. And the inner pad trim adjustment over the BB5s a needed improvement.
The CX-55 had been on the bike for Elaine, so I can not comment of use VS the BB7 setup as I did not rise it other than short test rides etc. I know they cost more, and the lack of adapters being included was both a pain and added to the cost difference. They were better looking FWIW. ;)

7/13/14 7:15 AM

quote:

---

In the motorcycle world, us manufacturer Buell has actually gone away from traditional dual hub-mounted disc rotors and instead uses a single perimeter-mounted rotor.

---

7/13/14 7:35 AM

quote:

---

This is not by any means the first time this has been tried. The problem with the single perimeter disc is the same as with a single hub mounted disc, the retarding torque is off center and tends to turn the fork under braking. Not a problem at bicycle speeds or even for most road motorcycle use but is at racing speeds and braking efforts.

---

7/13/14 7:42 AM

Better modulation?

7/13/14 8:02 AM

for cable-actuated disc setups, theyre not bad at all. at least the lever-to-caliper part of the brake system.

having to deal with rotor trueness (and dish) can be an issue with lower quality tackle but no worse than dish/true with rim brake systems.

7/13/14 9:16 AM

quote:

---

having to deal with rotor trueness (and dish) can be an issue with lower quality tackle but no worse than dish/true with rim brake systems

---

7/13/14 10:09 AM

i'm still new to disc, but i tend to think it's more of an issue @ initial setup. once trued the trueness would be unchanged unless you crash or do some sort of ham-fisted operation to tweak a rotor. and for discs you can just open up the pad spacing to just keep riding if you want.

for motorcycles, it's possible to warp rotors due to excessive heat buildup in a rotor mostly in racing applications. but unless you're descending some major cols i doubt it'd be a problem with a pedal-bike.

7/13/14 10:37 AM

The biggest con I see to road discs are front wheels. All the low spoke, radial, aero front wheels need more spokes, crossed spokes, and lose their aero advantages.

I've had discs on a mtb since 99, but I have no use or need for them on a cross or road bike. Keep it simple.

I also don't see the attraction of electronic shifting. Another battery operated device in my life? No thanks.

7/13/14 10:39 AM

Old fart...


I am with you though... ;)

7/13/14 10:43 AM

Heat dissipation is a problem on road bikes that mountain bikes don't have because road bikes go much faster. I think Tour magazine did a test in which the rotors melted on a test of a long descent. There's a youtube video somewhere...



The solution is simple. Bigger rotors.

On our tandem, I upgraded to disc brakes front and rear. Cable operated. 203mm, I believe is the rotor size. Squealed like a pig the first ride, but silent thereafter. No issues on numerous hilly rides.

Incredible stopping power and on a tandem we can definitely use it...

Sandiway

7/13/14 10:48 AM

Look, 695 TDF machine.

one of these.

http://www.lookcycle.com/en/all/route/gamme-premium/premium-695-aerolight-frame-pro-team.html

Full Campy Record (cable) drivetrain.

Less than 6.2 kilos in a 56cm size built up with Zipps.

Electric shifting is the bomb, if you ever see it and try it you will see the advantage. For the rear it is near on perfect. The front, mehhhh.

Last edited by ErikS on 7/13/14 10:54 AM; edited 1 time in total

7/13/14 10:49 AM

In my so far limited experience with disc brake, the front wheel stick out to be a problem because it got taken off for transport EVERY TIME!

Other people reported no problem with the repeated reromal of the front wheel. But unfortunately that's not my experience. Some rides, it's quiet as a mouse, other times, it squeals like a pig. Most times, it's somewhere in between, in different degree of noisiness.

7/13/14 10:51 AM

Sure looks clean...

A V front might be too powerful??

7/13/14 12:13 PM

Matt's has that gawdy Look blocky paint. Yuck. That bike is sweet. Understated and business.

BTW Matt can climb like a pro too. He does the bike no shame at all.

Top 40 in the Blood Sweat and Gears Fondo in NC a couple of weeks ago and he just about can pull an AARP card.

How can a V-Brake be too much if the disk is the next greatest thing.

That melted disk above is SCARY. No thanks!!!!

7/13/14 12:30 PM

While we are on bike looks/paint. Anyone notice Sylvain Chavanel rocking his old[?] IAM Scott.

It has a flip flop orange [with yellow and blue accents] paint like I have never scene. It goes yellow to orange, bright sun make it go yellow. But glows iridescent salmon under a brighter overcast days looking at the TDF stage shots.

Like!

7/13/14 1:31 PM

Klein

7/13/14 1:56 PM

There is an rider on a purple/blue flipflop Klein on Mondays Portland Wheelman ride. I like the yellow orange one better personally. ;)

I am taking the SS tomorrow, so this might be my last postings tonight... ;)

7/13/14 3:13 PM

According to Shimano, it's all about full carbon wheels. Unlike aluminum braking surfaces, carbon acts very differently under wet and dry conditions. The UCI was convinced to allow them when presented with a highlight reel of pros crashing on carbon rims due their unpredictable performance with rim brakes.

7/13/14 4:47 PM

...far more than I see for electronic shifting, now that I've tried it.

You get far better, more consistent braking in wet conditions. Unlike rim brakes, you don't have that "no brakes" feeling initially, followed by a sudden increase in braking power. This is likely what was responsible for many of the crashes in the Tour this year, as it's difficult to modulate rim brakes in the rain, whether you're on carbon or aluminum rims. In dry conditions, you still get better modulation with no variation due to rim condition or straightness.

Rims can be lighter because they don't need the special heat-resistant brake track material (carbon rims) or the extra reinforcement required to compensate for wear (aluminum rims).

There is no heat buildup at the rim, so there will be no issues with tubular glue softening or clinchers overheating.

Disk brakes are already becoming more aero, with Shimano announcing a new mounting system that should help improve it further. Remember, virtually all of the currently available disc brakes were designed for MTBs, where aerodynamics wasn't a consideration.

Weight will come down as well, though there will likely always be a small penalty to pay for disks. However, weight reductions at the rims will easily compensate for increases at the hub. Composite MTB rotors are already in production and the bugs are being worked out of them. I expect we'll see them on the road in a year or two.

I fully expect that there will be road-specific brakes with guides to speed wheel changes. Again, for MTB brakes this really wasn't a consideration.

Prices will fall, as they always do.

I have hydraulic disks on my 2 MTB and Linda's. While initial setup can be finicky (cutting brake lines to length, bleeding, etc.), once they're set up, they're largely maintenance-free, other than replacing brake pads, which is just as easy as with rim brakes.

Rotor warping from use is a non-issue, though you can bend them in transport or in a crash, but they're far from fragile. Linda and I have both gotten our MTB brakes so hot that they were smoking and the disks changed color, but they didn't fade and the disks remained true. For the record, this was on a ridiculously steep road descent in Point Reyes, CA.

While it's true the rim brakes are more than capable of locking up either wheel, that's really not the point. What matters is the degree of control you have before you reach that point. Yes, I've seen the videos of trials/stunt riders doing amazing things with rim brakes, but how many of us posses that level of skill, or ever will?

The positive comments on cantilever brakes really puzzle me. They are a complete pain in the a$$ to set up, provide marginal braking and are rather sensitive to pad wear, as it affects the leverage they produce. If what was meant is "direct mount" brakes, which are not cantilevers, yes they offer advantages is weight and stiffness and should work at least as well as any other rim brakes.

Obviously, we don't need disk brakes any more than we need electronic shifting, but they offer advantages currently and will only get better with time.