europa

For normal riding, even long days in the countryside, I wouldn't argue with you. I do wonder about touring where a blown hydro pipe leaves you without a brake or air leaks would leave you with weakened brakes - it's not hard to carry a spare cable and fit it on the side of the road.

dabac

While that would be physically possible, it just doesn't seem to happen often enough to be worth worrying about. Not on bicycles, not on motorcycles, not on cars
Maybe, maybe if you rode close to something and managed to snag the brake line.
If it did, you'd have to limp home on the remaining brake.

There is a bunch of parts on a bike that people "never" carry spares for. With brakes, at least you have two.
There is no logic to worry about a part so hugely unlikely to fail only b/c its new.

Air leaks - brakes needing bleeding - are generally slow onset events. I've never heard of one developing fast enough to be an issue while riding.

It should be possible to have rear length brake lines on both brakes, allowing you to swap brakes as another "limp-home" mode.

europa

You did note the first part of my post, where I say that for normal riding or even long days it's probably not a problem didn't you?

dabac

Yes.

Unless by "touring" you mean to go way off the beaten path - like several days between towns, I wouldn't worry about hydros there either.

Really, read enough posts and you'll find people who have snapped BB axles, pedal spindles, saddle rails, seat posts etc etc. All of them very unlikely to be carried as spares. And equal if not more ride-stopping than having one out of two brakes fail.

HardyWeinberg

I agree wholeheartedly that hydro disc fail is less likely than other systems but is there a separate master cylinder for each brake? In a car when you get air in the line all the brakes are affected.

Campag4life

So much for discs being an aero disadvantage...doesn't keep Kittel from hitting 45mph in the sprint. What a beast.


I guess with the ban lifted, I am rather surprised there aren't more disc brake bikes in the race. And I am not a fan of them being allowed with their hazard but who can deny they modulate better? If living in the mountains which I don't, I would probably own a disk brake road bike. For flat land riding caliper brakes are fine...and apparently caliper brakes are fine for the majority in the peloton.

Marcus_Ti

Yes.

Athens80

From Cycling Weekly:
I'll give you a topic: Richie Porte would still be in the TdF if he'd had disc brakes. Talk amongst yourselves.

Marcus_Ti

He at least came out of it fairly unharmed. Amazingly

3 days ago a 21-year-old pro at the Giro Rosa went down at 90km/h on a mountain descent....probably brain damaged, and is in a coma. Nevermind other injuries.

seypat

Not necessarily. There is a good chance he still would have wrecked. He did lock up a wheel, after all. There is an even better chance that he would have been taken out by Martin and that rider in the green. Poor Martin, he was going to be involved in a crash with Porte no matter what he did. Maybe you should be talking about Porte using some kind of ABS system. He might have avoided the crash with no wheel lockup.

Campag4life

No...he likely would have locked his rear brake on either. In the heat of the battle if going for max braking, either type will lock the wheel.


The next evolution in bicycle racing in particular as it has been a big game changer in motorcycle racing is ABS. With hydraulic disks, one may believe someday this could happen. Porte's accident was likely due to a wet road surface and his lack of bike handling skills....his position relative to opponents and on the road. ABS makes everybody better...car, motorcycle and if/when implemented for racing bicycles when descending 60 mph on mountain roadways in wet conditions when riders take more chances than they should, ABS will make a big difference. Really easy to lose that little tire contact patch in the wet as many of us have experienced but most of us ride much slower in the wet because we don't have to ride fast. Road gravel is a big game changer as it is on motorcycles as well. ABS on a bicycle would help a lot in this condition as well.

europa

This is what I don't get.
Disc brakes are supposed to be superior in the wet and down hills. Today is a mountain stage and it's happening in wet weather... yet Kittel isn't using disc brakes. Indeed, I'm pretty sure he didn't on the earlier mountain stages. Yet he does on the flat.
Any thoughts?

europa

Matthews, the other disc brake user, isn't using them today either. So are the so-called advantages illusory?

Marcus_Ti

123456

europa

That wasn't a racing cyclist, more someone built like me

dabac

Under race conditions, brake performance as such, isn't the limiting factor.

Dave Mayer

Nobody is riding discs in the mountain stages because the extra weight would represent an insurmountable performance penalty. Enough of a penalty such that the sprinters might not make the time cut-off.

They were used by a couple of riders on the pancake-flat stages as a marketing gimmick. Kittel is such in overwhelmingly dominant form right now, that he would have won these stages on a Pee Wee Herman cruiser bike.

Discs also represent a major liability in crits due to the constant accelerations. I was watching our local Pro/Cat 1 race last night. Out of over 100 guy entrants, a single rider had discs, and he was shelled off the back real fast. None of the ladies had discs.

Lazyass

The day Kittel won on discs he actually had a puncture earlier in the race. They said the wheel change did take longer. Since it was early in a flat stage it was no big deal. But an extra 20 or whatever seconds it took (they didn't say) can be a long distance in a mountain stage where you can be screwed if the group leaves you behind.

Campag4life

Europa,
Quite possible in climbing stages, Kittel is riding a Tarmac and not Venge. Pretty well known why he rides the Venge VIAS in flat stages...because of the superior aerodynamics of the Venge for high speed sprints. Aerodynamics if getting into literal rarified air at 40 mph + are a very big deal. The Venge caliper brakes...early VIAS was released with caliper brakes when the disk UCI ban of disks was in effect....were known to be crappy and why Venge VIAS bikes I believe you will find have disk brakes in the peloton.

For climbing, many would concede the Tarmac is the better and preferred bike. Apparently Kittel and most in the peloton are fine with caliper brakes because the Tarmac is available with disk brakes. It just so happens the design of the Venge...its integrated brakes were poor and disks basically saved the bike from being discontinued because even club riders hated the braking performance and pros were shying away from it as well. A little known fact is...when the VIAS was being designed, it was designed initially with disk brakes. The afterthought was the scurrying response to the UCI ban of disk brakes which caused some would say premature release of integrated aero caliper brakes on the VIAS which had widely reported poor braking even after Specialized tried to improve the design well after initial release of the bike. Even the 'new and improved' VIAS caliper brakes are generally perceived as poor to this day as often complained about on the web. Pretty obvious that Kittel and others don't believe that disk brakes themselves are essential on a Tarmac even though Tarmacs are used as all around stage bikes or dedicated climbing bikes in the peloton....certainly the most popular climbing bike. And of course, what goes up, must come down and most in the peloton still choose caliper brakes so they ok with fast descents apparently.
My thoughts.

europa

I'll wear that one, though in last night's stage, the only danger he had from losing time was missing that intermediate sprint. If he'd have been in the autobus, he'd have been able to catch up and finish inside the cut off.

europa

Fair enough. I knew there had to be a logical reason in there somewhere. Thanks for taking the time to explain it.

Campag4life

The aero versus conventional frame racing bike and disk versus caliper brake debate will likely not die down anytime soon. As known, old conventions die hard and sometimes new bike tech is slow to embrace. I will express surprise honestly watching the tour this year that most if not all bikes are not disk brakes. Most bikes in the peloton are still rim brakes. Btw, if not living in the mountains and riding courses with a lot of hills, I am not a fan of disk brakes because of maintenance mostly...and I have owned disk brakes bikes. But...if living in the mountains, pretty much all I would own are disk brake bikes and yet pros...and they have a clear choice certainly as team members of Specialized and most brands, the majority of the peloton is still on caliper brakes. Surprising. Simply suggests, that pros who test both weigh the pros and cons and don't believe its that big of deal...even though they will encounter likely wet conditions because its common in the mountains with elevation changes. Again, a bit surprising. Most current pros grew up riding caliper brakes and of course have done countless testing at 60 mph descents in preparation for big races like the TdF. This will likely change in the next 10 years as disks become more common if perceived as not a threat in pro racing. I really believe a disk guard should be developed but there are design challenges with implementing this effectively or they would already be in effect.

The aero versus more conventional tube frame bike debate is equally if not even more blurred as to what is preferred. This is changing as well on many fronts. One, big races due to competition are looking for every conceivable option how to make their riders faster. Used to be, riders rode more purpose built bikes like custom endurance bikes with shorter head tubes like custom Specialized Roubaix in the race it was named for. Longer wheelbase bikes with more laid out angles that attenuated road shock better. They still do ride bikes designed for the classics with wider tires and lower pressure and longer wheelbase. But what we are seeing now in races like the TdF is riders opting for specialty bikes...like Kittel. Aero bikes for flat stages and climbing bikes for climbing stages. I don't believe Froome by contrast is changing bikes per se. His Dogma is more of a 'blended' bike by nature though...not unlike the diversely talented Froome. The Dogma has good but not great aero dynamics and of course it climbs as great as the great rider himself. A good match in other words. Froome is not a sprinter and so a bike like a Venge VIAS may not offer the value it does to a guy that like Kittel who can hit 45mph. Cav also rode the Venge and no surprise Cav gets his speed largely by aerodynamics...the most aero sprinter in the peloton and likely the lowest watt sprinter due to his small body that we learned can't fit through all small gaps in the peloton.

So the peloton is changed. More purpose built bikes for dedicated stages to exploit rider advantage based upon rider strengths and weaknesses.

All said, does it really matter that much in the grand scheme? I believe in the TdF it does. There have been two photo finishes this year in the TdF for example. It matters much less for the weekend warrior.

Also keep in mind in recent years, both Contador and Nabili have both won the TdF on a Tarmac...considered one of the best all around road bikes on the planet. Also, Sagan won the World Championship the year before on the Tarmac. But with bike tech moving forward, I don't think many will be surprised to see a GC winner of the TdF win on an aero bike with disk brakes...as aero bikes become lighter and more compliant and stiffer where needed and disk brakes reduce weight and aero drag coef. March of tech is undeniable.

Maelochs

Okay, so here you are saying it isn't about competition.
and again .... nothing to do with racing.

Then someone mentions riding int he rain, the one thing disc brake proponents keep coming back to ... and ....

Suddenly you realize the hole in the argument ....

and come back with this, but the fact is, most people who ride int he rain and are Not racing are commuters who are not the big disc-brake market.

Actually it is a radical change. If it weren't we wouldn't be discussing it.

Discs offer better performance in the wet, but it is marginal; (as a commuter with rim, hydro discs, and mech disc bikes, you can tell me whatever you want, but when you start telling me to ignore my own lived experience, I stop listening. Yeah, i Do believe my lying eyes more than I believe you.)

Actually the commuters are the best customers. The extra strength and weight of the fork and rear triangle don't matter so much because most commuters carry a rack (or a knapsack) and most commuters aren't going for speed records in a serious way.

Urban commuters are the best prospects. On a rainy day, with frequent stops and a lot of traffic, with drivers getting stupid in the rain ...

One thing I and only one other poster has mentioned though ... tires make a lot more of a difference, particularly on the pavement in the rain. Say what you like about "modulation," but most surprise braking events happen so fast pumping the lever isn't a reality. With the greater power of discs and the lower traction of wet pavement, locking up and skidding is easier, and the system is no safer.

Discs are not yet a clear improvement over calipers for most road-riding situations. Every says "hand pressure" but no one Ever mentioned it before, because it's really a non-issue. No one holds their brakes long enough to exhaust the hands and forearms ... and no brake system which is set up properly takes that much force. I can lock up caliper brakes with two or three fingers without a problem, so the pressure needed isn't an issue.


The biggest drawback to discs is the added weight---not just for the brakes themselves, but for the extra reinforcement needed to support the braking force at the end of the fork. Hydros are more complicated--but not impossibly so. But a lot omore complicated than calipers.

Spyre mechanicals are a huge step inthe right direction ---not nearly as strong as hydros, but with dual pistons, as easy to adjust as calipers. Big step forward.

Once the weight comes down more and the simplicity goes up, discs will start to be no "radical change." It will be another few years, I think.

But yeah .... pretty much right now disc brakes are a marketing tool. Manufacturers cannot add another cog in back very easily, and changing to a wider spacing would take Huge cooperative effort---wheel-makers, frame-builders, and all the components which go into wheels would need redesign ... and manufacturers would have to run multiple production lines because so many 11-speed, 130-mm drive trains/wheels are out there already.

So ... what can component makers make to push new products, and what can bicycle manufacturers put on their new-season bikes to make people think "I need the newest upgrade?"

The answer is ... "Disc brakes." And really, the difference is about the difference between ten- and eleven speeds ... really minor for almost all riders.

I have two road bikes with 11, one with 10, one with 9, one with 7 and a triple. The only one which really is a cut below is the 7-speed triple, and that is only because it is a cobbled-together set-up which doesn't work well.

11 is okay ... but so are ten and nine, and I would happily upgrade the 7- to 8-speed if it wasn't a vintage Al frame.

In my experience, it is the same with discs. not a bad thing, not a big benefit.

yeah, people who want to run carbon wheels are Way better off with discs. So for that matter are people with steel rims, but I doubt there are a lot of them, either. People who food a Lot of fast or heavily-loaded descending are probably better off with discs due to heat dissipation.

People who commute, particularly in urban regions, and particularly in rainy regions, are probably better off with discs.

People who live in the Pacific Northwest ... discs.

Otherwise for road riders .... not yet worth it.

There is a breakdown on why Marcel Kittle used a disc Venge ... and it comes down to bad design. If the Venge had decent brakes---like normal caliper breaks, like all the rest of the sprinters use---then Kittel would have used calipers. After all, his whole deal on sprint stages is speed, not braking. We all notice he uses caliper brakes when climbing.

Interesting, that---because descending, you'd think discs would shine. Except ... the pros, who really care, choose calipers.

Maelochs

Except of course, that your example is ridiculous. Discs on dry pavement don't offer any better stopping. Tire traction, not brake force, determines stopping. And in a peloton, where you are right on top of other riders, reaction time is the determining factor--and awareness. Crashes happen because no one can see the crash until it is too late to either stop or go around ... and if they do either the other riders will hit them anyway.

Maelochs

This is about the whole story.

As I recall the GCN video wasn't exactly a head-to-head test, but was close. The dangers of discs are false, IMO (just IMO) but the wheel-change thing is real and very significant. Look at Dan Martin, who crashed because he got the wrong wheel---with rim brakes. Already neutral service cannot keep up ... with discs the chances of getting the right wheel in a hurry would be far worse.

Discs carry a weight penalty for those who care.

Discs in three or five years will probably be on par with or ahead of calipers in every way. Not yet. And the different brake systems will still be a problem for competition, perhaps.