forgive my ignorance but in these high speed crashes where people get tangled up in bikes...does anyone else see impending serious injury of a disc brake slicing through skin like a sharp knife?

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@rhyspencer

If they're inboard of the forks and dropouts, then they don't seem any more dangerous than the chainring or rear sprocket. The improved and more consistent braking performance might prevent some crashes and reduce some kinds of injuries, even if the discs buzzsaw through some calves in other incidents.

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STAC Zero Trainer - Zero noise, zero tire contact, zero moving parts. Suffer in Silence starting fall 2016

This. Twitter should prove amusing...

burns are far more likely that getting cut up. I have more than a couple of friends with the MTB rotor branding...

That is the concern I have always raised with discs on road bikes.

I have no problem with teams beginning to use discs. I do hope that does not mean that disc use becomes mandatory.

This is an important step in the evolution of braking technology for road bikes. It does not mean that it is the "right" or "best" option,minor the final stage of the development process. What the "final" step is could look substantially different than where we sit today.

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

ErnieK wrote:

burns are far more likely that getting cut up. I have more than a couple of friends with the MTB rotor branding...

Burns will only happen if the brakes have been actively used in time proximity to a crash. Brakes take time to heat up and time to cool down.

We also know that burning of skin has several grades of injury based on the temperature and time exposure to the heat source.

Where do people crash most?

• Descents: Usually not a pile up situation, a lone rider crashes himself or one other rider. Discs have the potential to be hot/warm here. Pros are braking hard into corners, but not dragging brakes for long periods so the rotors have high chance to become cool at descent speeds.
• Sprints: Large pile ups. Likely to land on your bike or another bike. Ain't no body on the brakes in a sprint. Rotors basically at ambient.
• JRA on flat in peloton: Can be a bit pileup, caused by wheel touches/road furniture. Riders usually are not actively braking in these situations but group speed is high. Rotors will be at ambient or at temperature of 2-5sec of hard braking.

I just don't see the big risk of rotors burns in road racing. The risk situation for road races is very different with regards to mountain biking.

agreed, however that also shows why disc brakes are unlikely to have a big effect on crashes.
crashes on descents may be reduced, though more likely riders will leave their braking later and so crash at higher speed.
the mass pile ups where both volume and severity of injuries are highest are unrelated to braking. road furniture, peloton size and other vehicles are the big crash causes they could try to reduce.

i have mixed feelings as i think it may be helpful for the recreational public to get discs more prominently used but i don't see it as being important or maybe even appropriate in racing at any level. and cycling is not F1 where technology really is driven by the top-level racing... though maybe it could be if the UCI really relaxed the rules, again not so sure that would be a good thing.

overall, meh i can't see it being a big thing either way - just the UCI bowing to pressure from manufacturers who want to be able to show off their new tech

This risk is easily mitigated by requiring the disk to be a certain thickness with a fully radiused outer edge. What isn't "sharp" can't "cut" you. Also, it would be a good idea to ensure all the inner edges have a generous radius.

Probably the only mechanical risk you can't mitigate well is the finger into a spinning disk problem. You could require solid discs or a limit to the size of cutouts/openings to prevent finger insertions.

I've never in my years of following bike racing have seen or heard of someone getting into a crash & having their fingers or hands get caught in the spokes of a wheel. If that is rare, hitting a disk brake in a crash will be too.

One good thing that could come of this is a standardization of axles and dropout spacing. I am intrigued by some of the disc models on the market - they wouldn't be my racing rig of choice but might be nice for a winter training or endurance bike for example. But they are all no-go until some semblance of standardization is in place such that the parts you buy aren't completely useless on another bike. That time is probably a couple years away yet.

Michele Bartoli almost had his knee cap sliced off by a four spoke Spinergy wheel.

This. This. And this.

I'm so tired of all these strawman* arguments about the dangers of "new" technology -- which, by the way, have been accepted for MTB for 15 years and have yet to cause an injury serious enough to revoke their usage.

"One rider...almost" = So should we ban the HED trispoke? It's functionally the same as the Spinergy. What about MadFiber?

Disc brakes simply are not problem. Injuries happen from riding bikes, not from parts that are manufactured and used correctly and typically.

However, when the typical physics of riding are disrupted (as in a crash), no single component is inherently more dangerous than another:

• A stem can crush your testicles
• Clipless pedals can keep you attached to the bike like a rag doll
• A saddle could rip your rectum into a dozen fleshy pieces
• A helmet strap could get wrapped around your throat and strangle you under the right conditions

The point is, we ride at a high rate of speed on an unforgiving surface. SOMETHING has got to give, and usually it's our soft, frail human body. If you can't accept the risk, get out of the sport.

Another example: Modern steel guitar strings can snap and prick my finger or, God forbid, poke my eye out -- but it's just not a prescient concern, especially because they work better for their purpose than old-school nylon and cat-gut.

*not a personal attack, Arch, it's just easier to say "you" and "me"

The UCI has been hinting around at this for something like 18 months and they are doing a limited field test, which means that they may conclude that disc brakes aren't yet appropriate for road racing. I think they are navigating the middle ground between whole sale adoption and banishment pretty well. The previous administrations of the UCI would have never had the vision or interest to let the sport adapt.

I personally don't think disc brakes for road are a big game changer but I'm also not terribly bothered by the move. All my current stuff keeps on working and it affects my life in very few ways, except to say that when some amateurs jump on the bandwagon I'll be at the ready to buy their old wheels at a bargain.

Is the use of disk brakes that much better then the traditional rim brakes? Is this technology for technology's sake?

I don't know, I've never had any problems with my boring stock brakes.

Right. If spinning objects that can cut you is a concern, then watch out for the spokes.

1) No, a Spinergy wheel is NOT functionally the same as a Spinergy wheel. Not even close.

2) Are you familiar with Bartoli's accident? The "almost" was not meant in a "whew, that was close" sense but in the "my knee cap is hanging on by a thin slice of flesh....I almost had it chopped off" He stood up and his femur pushed out from the knee. It was a serious and grotesque injury that nearly ruined his career.

Your other points re: different components causing injuries are strawmen. Saddles. stems and helmet straps are necessary pieces of equipment. Disc brakes are not. While I don't share the concerns of others re: a spinning disc, I do think it is fair to question the burn potential form rotors. I've seen guys get burned....it ain't pretty.

And I am by no means anti-disc on the road.....

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

why not just add a piece of carbon fiber over the disc to prevent burns and such? Its a road race so we dont really get that much grime in the discs :)

I have the scars on my fingers/knuckles to prove it does happen (state crit champs 2011 and wearing full finger gloves no less) and I've sewn up another guy on just a training ride. Those CX-Ray spokes are damn sharp!

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Fatigue is biochemical, not biomechanical.
- Andrew Coggan, PhD

I am familiar. It was horrible. If you're volunteering to put your hand in a trispoke spinning at 35mph to show me how much different it is, I'll buy you a pair. Video posted to this thread, please.

Is the forum familiar with this from three days ago? https://www.youtube.com/watch?v=hRM3bFXlyNk -- maybe discs would have helped.

Or this piece of wood through a guy's leg? https://www.youtube.com/watch?v=dk8guSC4WFo --- I'm sure they thought the track was perfectly fit for the race.

If you look hard enough, you can find an example of any component having a catastrophic failure or contributing to a bad injury. But I'm having trouble finding widespread reports of severe burns, chopped-off fingers or career-ending injuries from bicycle disc brakes, which have been used widely in MTB for over a decade.

MAIN POINT: I believe that the relative risk is hugely overstated. Another poster in this thread nicely summarized the empirical evidence --- that there is little likelihood of all rotors being hot at the time of a multi-rider crash. In fact, a major benefit of disks is that they dissipate heat relatively quickly.

*Also, "necessary" is ALL relative because this is a hobby. Helmets weren't deemed necessary until the early 2000s, and now there are people on this very forum who will tell you that they SITLL aren't necessary. That's what I'm trying to point out -- the fact that we are all discussing/disagreeing over something selfish and expensive and totally unnecessary to life.

The UCI is a relic! Bike weight restrictions, slow adoption of new technology, etc etc. I firmly believe their restrictions have held back the manufacturers from producing some really amazing new cycling products. Look at whats been happening in the Triathlon world when manufacturers get a carte blanche. Felt IA, Scott Plasma 5, Shiv Tri just to name a few that have had amazing leaps forward for consumers. Perhaps the UCI only focus on Pros but the fact is the manufacturers need to produce the bikes for Pros to race on. The R&D spend to do an entirely new line for consumers is what has lifted the cost of bikes in recent years or is at least partially to blame.

Overall the disc brake technology is out there and the UCI needs to at least do trials rather than just write it off. To the point about burns ... I'd opt for a dip in Silicon rather than Carbon Fiber. Silicon is soft, rubberized and it prevents heat quite a bit (up to 500F). That being said I'm sure there are some kinds of draw backs to doing that. Perhaps it also keeps the heat in rather than dissipating it quickly. If regular disc brakes have worked for MTB for so long I don't see why it won't work for road cycling.

/end of rant

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"Train so you have no regrets @ the finish line"

You realize that the crash was caused by rider error, right? Had very little, if anything to do with braking issues. And again, I am not arguing against the idea of discs on the road necessarily.


Another strawman. See previous post.


More strawmen. We are not talking about a "catastrophic failure". We are talking about the potential of injury as a result of normal product use. If you aren't aware of people burning themselves with disc rotors from MTB, I would suggest you aren't paying close enough attention.


perhaps.....that is what the trial period is for (among other reasons). I don't see what the problem is with raising potential issues ahead of time. (side note - the other poster's summary is NOT empirical evidence. Logical, perhaps....empirical, no.)


Still building strawmen....and helmets have been necessary since the 80's. But you cannot have a bicycle without some form of a stem system or a saddle. Nor can you race without a helmet. You can both have a bike and race without discs.

Again, I am not against road discs necessarily, but I do think they aren't really that necessary either. Gravel / Cross bikes? Sure, absolutely. Do the benefits of a disc system extend to a "oure" road or TT bike? Sure. Do those advantages outweight the negatives? Yet to be proved.

[/quote]

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

Ummm...because then you'd be right back to the silliness of trying to brake on a CF surface, except now on a significantly smaller diameter surface with the proportional decrease in braking torque...not to mention the how horrible CF braking surfaces are in the wet.

No grime? Have you ever ridden through puddles or in a rainstorm?

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http://bikeblather.blogspot.com/

I found this quote from the originally linked article interesting:

“I am not a technical expert but we learned from many others that the difference in performance between good and bad rim brakes is already high. So the performance of the disc brake which is maybe a little bit better than the best rim brakes doesn’t really bring a big effect to the total difference.”

So, if the performance of a separate disc brake is only a little better than the best rim brake setups, tell me again why there's such a big push to adopt a technology that by necessity adds weight and aero drag (not to mention OTHER compromises...like chainstay length minimums, rear wheel spacing changes, necessity for thru axles, pad contamination from road oils, etc., etc...)?

What they should really do is specify minimum braking performance criteria, and then let everyone figure out what is best from an OVERALL SYSTEM standpoint, IMHO.

I'd love to see an independent, comprehensive braking performance test pitting the road disc offerings vs. the best in class rim braking setups...and then not only compare braking performance, but then also the effects on overall system performance. I think it could open some eyes. I really wish I had the resources/time for that...

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http://bikeblather.blogspot.com/

I was referring to a CF cover plate over the disc (like a car's wheel well). Yes i have ridden in snow/rain, it gets dirty but if there is enough room in the well it should work i think?

because the demand for the product is there, plain and simple.

For some people, the benefits (or even perceived benefits) outweigh the negatives. The fact remains that the overwhelming majority of road cyclists (most of whom don't even race) don't care about aerodynamics. Me, I'm not jumping on road discs anytime soon and hope that they prove to be unnecessary by the time I would need to make that choice. I am perfectly content with my 10 speeds and rim brakes. Both my bikes (Shiv TT and Venge) are good enough that no new models warrant the expense in buying new bikes for years to come.

No desire to be an early adopter of any technology anymore.....which, given that I was almost always one of the first guys with the latest / greatest, is quite a statement!!

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

I think it's important to look at the functions and benefits of disc brakes that are not necessarily related to "better" braking performance. The same advantages of disc brakes apply to road bikes as they have to mtb and cx bikes for years...

• Consistent and reliable braking performance in all condition
• No more choosing the "right" pad compound based on rim material
• No more worrying about wearing through rim breaking surfaces
• No more brake drag in the event of a broken spoke.
• No more worrying about rim width as it relates to caliper adjustment
• No more brake fade in rain or mud or whatever.

The weight issue is a moot point, imo... it's very easy, and becoming less and less expensive, to build complete bikes that are pounds below the UCI weight limit. Adding an extra ~100g of brakes isn't hurting.

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feltbicycles.com - wilcouchatfeltbicyclesdotcom - Facebook

I read his description as a CF heat shield, not a CF brake disc.

I love how they wait until the end of the season to "test" this new change out. If they allow it moving forward for next year, m not going to lie, it will be nice to hace one bike that you could race road, gravel, and cross on if you wanted!

I haven't seen anything that actually substantiates a decrease in minimum stopping distance with disc brakes.

I don't know of any studies or tests at this time, but they may exist. Due to the small contact patch of a road tire minimum stopping distance will not improve dramatically. The more dramatic benefits are the ones I listed above.

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feltbicycles.com - wilcouchatfeltbicyclesdotcom - Facebook

I agree with most of your points, however, disc brakes introduce new disadvantages:

- Less aero
- swapping wheels isn't a simple 20 second barrel adjustment of the caliper anymore, but possibly a re-centering of the disc caliper and some possible more fine tuning.
- disc rotors can be inadvertently bent, and will either need to be straightened or have the pistons opened up and travel more (depending on model of caliper)
- periodically air can get in the brake line and will need a re-bleed
- Lever travel (at this point) is difficult to dial in on most systems
- cold weather performance may suffer particularly when using mineral oil
- if oil or other lubricants get on the rotor and/or pads (or even oil from your skin) then performance may decrease and way be noisy

I have 10 bikes and 5 of them have disc brakes and the above are just some of the issues I've encountered.

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There are certainly disadvantages and compromises to be had, but the same can be said with rim brakes. Many of the disadvantages you mention were popular points when mtbs were first transitioning. I'm sure you will see most of these points addressed for the road market as more options/models/etc become available.

In the end, I think (and this is my personal opinion) that the advantages of discs outweigh the negatives, making them the better option.

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feltbicycles.com - wilcouchatfeltbicyclesdotcom - Facebook

AKA, a "fairing"...not allowed.

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http://bikeblather.blogspot.com/

Yeah. Let's see what's happening in triathlon. Forty-year-old nobodies buying $10K bikes so they can move up from 37th place to 36th. Despite the ostensible reasons given about safety, the UCI rules were made to keep racing a competition between riders rather than their bikes. That was the main driver that produced the Lugano Charter. The racing would be just as good if the riders were restricted to 1980's bikes. The current UCI president has decided to make the UCI the industry's bitch.

As far as disc brakes, I am indifferent. I live in a climate that is fairly dry during the bulk of the year. Discs won't make a difference on flattish ground. In the mountains, the only advantage is less hand fatigue for switchbacked descents. I ride in winter when the roads are wet and there is slush here and there. It would be nice not to have to deal with the sound of gritty brake pads grinding aluminum rims down.

The ironic thing is that in bad spring weather or even threatening weather, I hardly see any other riders. As soon as the temperature pops up above seventy degrees and the skies are clear, everyone is out and kitted up like wannabe pros. Basically, the riders who will buy into disc brake marketing are the ones who are least likely to find any advantage to using them.

As mentioned in the post above, a big gain from pros using discs may be standardization. Right now I don't care to pay Kent Eriksen to make me a disc gravel bike only to have standards change every two years.

Nope. wrong. sorry.

The idea that the organization that was turning a blind-eye to doping was at all interested in fair competition is laughable.

The Lugano charter was nothing more than a backdated TUE to cover up what was driving the product restrictions. Verbruggen was offended by the new bike designs and decided to stop it.

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

Disc brakes burn, slice, otherwise injure. Cold air might affect the fluid, liquid could get on the disc and affect brake performance.

This thread is great, it's basically the slowtwitch equivelant of Edison trying to bring up all the reasons why AC powered light bulbs were going to kill us all, or someones great great grandma complaining that "horseless carriages" are too dangerous and noisy.

There is no connection between doping and equipment restrictions. The Lugano Charter includes not only definitions of what an acceptable bike is but it prevents the use of equipment that is not available to all competitors. The charter was not just a response to the crazy bike designs of the early to mig 90's, it was a response to very expensive one-off prototypes being used in competition.

I'm of the opinion that there would be far less $10k bikes without massive R&D costs needed to produce PRO level and CONSUMER level products. They will exist certainly but not in the abundance they do currently. Secondly the argument about bikes keeping standard to keep competition "level" is complete and utter bullshit. The riders themselves are all different sizes, shapes and weights. Making 1 variable of many "standard" does not do this, you're drinking the kool aid. They don't all have to use 24mm tires is a quick example of how a small change in products make this "standard" superficial immediately. Unless the UCI built bikes are the exact same only changing to scaling up the size while putting on identical components it's not about just the riders. Again more absurd UCI rhetoric which is holding back true innovation in the space.

Furthermore what's wrong with people with the means buying $10k bikes even if they aren't on a podium? None of those people pay for a bike, they sign a contract so who's going to fund the R&D? Whats wrong with wanting to feel like a professional? Whats wrong with spoiling yourself if you have a passion for cycling?

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"Train so you have no regrets @ the finish line"

I didn't say there was a "connection". What I said was the idea of the UCI being worried about fairness of competition, when they were turning their heads to rampant doping, is laughable. If they were worried about fair competition, they would have done something about doping.

Again, the Lugano Charter was the equivalent of a backdated TUE....a trumped up PR move designed to get people to go along.

Never mind the fact that much of the Lugano Charter has been routinely ignored....unless you have seen a snub-tailed Selector available at retail as but one example.

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

When you get down to it, isn't the real reason for this and all the other changes just to get us to buy a new bike? The bike industry isn't stupid...look at all the various "standards" and wheel sizes in MTB world.

So, if the performance of a separate disc brake is only a little better than the best rim brake setups, tell me again why there's such a big push to adopt a technology that by necessity adds weight and aero drag (not to mention OTHER compromises...like chainstay length minimums, rear wheel spacing changes, necessity for thru axles, pad contamination from road oils, etc., etc...)?

You know why. Marketing. Getting people to buy a bunch of new high maintenance stuff.

From talking to the guys at the LBS, hydraulic discs on MTBs are a pain in the ass. At least around here (dry climate). They are always needing to be overhauled. The owner put mechanical discs on his own bike. Actually now that I think about it, even the LBS owner on Kauai (totally different climate) complained that many hydraulic discs just didn't work well.

With all the dish these days the rear wheel on a road bike has a hard life, but the front can be built light with few radial spokes. Disc brakes make it much tougher on wheels especially the front.

Absolutely agree.

By far and away, the most dangerous things that can happen to you on a bike involve having your brain suddenly decelerate or rotate from coming into contact with a hard surface, or your spine being subject to excessive pressure.

If you are able to control your speed and location on the road better (as road bikes with disks appear to offer), then you decrease the risk of serious injury. It would take a very dramatic increase in burns or slices to make up for a decrease in brain injury.

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'It never gets easier, you just get crazier.'

No.

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

I'd say you need to find a competent LBS. hydraulic brakes are not that hard to maintain.

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

This, and likewise with the weight and maybe even aero restrictions. A minimum weight of 6.8kg is a meaningless standard with regard to safety, likewise with a type of brake. I am a civil engineer professionally, and it is drilled into us from day one that it is almost better to specify performance rather than to specify a process that gets you there. The reason for this is twofold - firstly that you are much more likely to get the result, and secondly that you force more liability on the party working for you.

Given current standards someone could, (absent other fine print) blame the UCI for a carbon bike exploding in a race since anything that is 6.8kg and over is considered safe. A more appropriate standard would be to survive x number of impacts to a bus at y miles per hour, a bike must have so many grams of aerodynamic drag under certain conditions, must be able to stop in a certain distance with tires with a certain friction coefficient and a certain rider weight and weight distribution, blah blah blah.

Granted you hit some kind of practical limit where those kinds of specifications can be pretty difficult to enforce and replicate. But it makes the standards meaningful, and more importantly (like you said), opens up creative avenues for teams and manufacturers to get to the end goal.

A couple of other points for those whining about road discs: Rim brakes aren't going away, keep riding what you want. For those of you who submit that they aren't necessary on road bikes, I submit to you that they are absolutely necessary... to keep shops and manufacturers in the black. If you don't release new and exciting products for the masses, they won't keep buying your stuff, and you go out of business. If ST-ers won't buy it, someone else will :-)

Pro DH MTBers used to race with cantis...;) I love the disc brakes on my CX and MTB bikes, but opt for alloy rims on my road bike in the mountains. Works for me!

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"Most of my heroes don't appear on no stamps"
Blog = http://extrememomentum.com|Photos = http://wheelgoodphotos.com

Because brakes convert kinetic energy into thermal energy, and as a function rely on both being a very effective and substantial heat sink, and secondly able to shed heat to atmosphere to work.. As soon as you guard the brakes you insulate them from the very air required to remove the heat through convection...
ie you reduce the capability of the brake..

Making a guard which also catches and channels air is of course possible but will in all probability introduce additional aero drag (at zero and shallow yaw) which some quarters are already stating as being a big issue (it really isn't, most of the additional drag of disc is from the wheel spoke pattern and the rotor at higher yaw anlges......

I already have a road disc bike, and disc CX bike and disc MTB bikes.. for me they are better for certain applications... its just another case of the right tool for the job..

How?

Braking torque. With rim brakes the wheel doesn't need to resist torque, but with disc brakes it does. A lot. Plus with rim brakes the wheel is laterally supported at the top when brakes are applied.

So with disc brakes you need more spokes with tangential lacing and a hub with a larger flange.

I'd say you need to find a competent LBS. hydraulic brakes are not that hard to maintain.

Currently I'd have to move to have any LBS. They never worked on my bikes anyway, I'd just go in to shoot the shit.

I don't have any bikes with hydraulic discs but apparently they are unreliable, which is why people kept bringing them in specifically for service. But hey, more money for manufacturers and mechanics.

Sorry for all the long posts. I just have to disagree based on real-world experience. POINT: Professional mechanics who complain about hydraulic discs are NOT using them correctly. It's not even hard for an amateur, using a kit and a YouTube video, to replace pads or bleed a line.

I ride MTB on average once a week throughout the year, and in 13 years (two bikes), I have had to bleed my disc brakes 3, maybe 4 times. (One of those times was from driving from Tennessee to Colorado at 9000'.) I've taken my bikes to many different shops, and they've all confirmed that the brakes were in great shape.

Other question: Do you really think the average road wheel has a harder life than the average MTB wheel, given the same ride time?

http://www.notubes.com/ZTR-Flow-EX-C167.aspx --- the gold standard in aggressive, all-mountain wheels. Aluminum, tubeless, 1900 grams, 29mm external width, 32 spoke: $600 for a set.

http://enve.com/...s/m-series-50-fifty/ --- Many roadies and triathletes gladly pay $2500 for a carbon wheelset. --- Sub-1500 gram carbon disc wheelsets, 28 spoke.

POINT: It's easy to built a good quality, strong, reasonably priced disc wheelset. It's harder to build one that's:

• as light as a Lightweight
• as strong as a Mavic Open Pro
• as aerodynamic as a rim-brake Zipp 404
• as cheap as a set of Aksiums

But isn't that why we buy new gear? When you buy a set of Zipp 404 Firestrikes, you're not paying specifically for that set --- you're paying for the R&D and the molds for the next-gen 404 Firebombs (release date 1Q17, patent pending).

POINT: Incremental improvements are still improvements. I really, really wish that everybody who thinks it's all a marketing scam would be forced to ride a bike with cantilevers and argue that modern side-pulls aren't better. In 10 years, I will get those same people to ride 2015 Dura Ace 9000 and argue that discs weren't an improvement (even if they lead to a completely different overall solution, like hydraulic rim brakes or electromagnetic brakes inside the hubs).

Hydraulic discs are hardly unreliable. In fact, I have a set of Hayes hydraulics that I have never once had to do any work on in over 15 years.

Sounds like user error to me. Like I said, find a competent LBS.

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

Not necessarily...the use cases are different. I can point to many technologies that make sense for one discipline that don't for another.

I'm afraid you're falling for the common fallacy of comparing "best in class" performance of separate braking discs with the full range of rim caliper performance. Let's compare "best to best", Ok? How about we explore the ramifications of Hed's claims for their new "Turbine" brake tracks, which result in "...25% shorter stopping distances in dry conditions, or 70% shorter stopping distances in wet conditions. Additionally, the consistency of stopping distances has improved by nearly a factor of five. "? Combine that with data from SRAM showing that the HRR rim brakes on aluminum rims result in braking force within 10% of their hydraulic discs w/160mm rotors (which would imply at least equivalency to 140mm rotors), and do you think that maybe there are some largely unexplored improvements left in the current "Rim Aero Integrated Disc" designs? ;-)

Aaah...see, there's part of your problem right there. CF surfaces should not be used for braking on bicycles. Now, before you respond that rims with aluminum braking surfaces are too heavy...think about the fact that you're already willing to add weight to add additional braking surfaces...so what's the problem?

See the comments above about the Hed Turbine surfaces...or, the PEO coated Mavic Exalith brake tracks. Going to be difficult wearing through those...

OK...on these 2 you're just picking nits. Admit it.


See comments above about the Turbine brake tracks...but, I find it odd you don't mention brake fade on long descents for additional discs used on road bikes...nor do you mention all the other downsides of additional braking disc on road bikes (my new favorite one is the admonition to needing to be careful when washing your bike so that you don't contaminate the pads with road oils/grime...WTF? Really?)


Exactly...and yet why do people say that rims with aluminum brake tracks are too heavy and insist on running rims with CF brake tracks? If you're OK with adding mass for marginal improvements in braking performance, why not do it in the way that has the least compromises on the rest of the system and doesn't result in wholesale changes in the bike designs?

When looking at it from an overall system standpoint, it's really hard NOT to conclude that a large part of the clamor is based on just thinking its "cool and more advanced", whether or not it actually is a net gain.

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http://bikeblather.blogspot.com/

So what you're saying is rim braking can be equivalent with Al surface and the right pads, to pretty much any disk setup regardless including carbon?

How much have you tested disk on a road bike? More than a couple laps around parking lot at Interbike?

I've ridden a gravel bike with disk since this spring without any service at all. And that included a 100 mile gravel race with more technical branking situations than any road scenario.

+1

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feltbicycles.com - wilcouchatfeltbicyclesdotcom - Facebook

POINT: It's easy to built a good quality, strong, reasonably priced disc wheelset.

Of course. Is anyone claiming otherwise?

It's harder to build one that's:

as light as a Lightweight
as strong as a Mavic Open Pro
as aerodynamic as a rim-brake Zipp 404
as cheap as a set of Aksiums

Poor choice of argument. Rather disc brake wheels are:

Heavier
Weaker Wheels
Less Aero
More Expensive

And for all these negatives we get a minor incremental improvement. Better braking in the wet. Less hand fatigue on long descents. That's basically it.

Incremental improvements are still improvements. I really, really wish that everybody who thinks it's all a marketing scam would be forced to ride a bike with cantilevers and argue that modern side-pulls aren't better.

Decent cantilevers properly set up are just as good. Plus changing from cantilevers to sidepulls didn't require a new frame and wheels in addition to the brakes. Neither did it entail all the negatives that disc brakes do.

This is an incremental improvement that most road riders won't even care about, that brings a bunch of negatives along with it that everybody should care about.

I'm not understanding what you're trying to ask in that last part about carbon...

It's been more than just those hot laps around the USA Crits Finals course...but I think you know that ;-)

Besides, didn't you see my first post above lamenting the lack of ACTUAL performance DATA in this discussion? Ride tests can only tell you so much, and confirmation bias is a tough one to get around, especially in this case...

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http://bikeblather.blogspot.com/

And ability to run bigger tires, which may not matter to some but is certainly a benefit to year-round and mixed surface riders.

Funny to me that people who haven't even ridden disk brakes are such experts on how they work. You haven't ridden disk yet claim they're just as good as cantelever. Alternatively, a guy like Tim Johnson, who has actually tested both, claims the opposite. You and Tom are so bent on shouting them down that all sense of objectivity--and thus credibility-- is lost.

So what you're saying is rim braking can be equivalent with Al surface and the right pads, to pretty much any disk setup regardless including carbon?

Road bikes are simply not "brake challenged". Except in one situation, switchback descents with carbon rims in the rain. And that is based on the testimony of others, because if I thought that situation would arise, I'd just put on my aluminum clinchers and still have a lighter and more aero setup than a carbon rimmed disc brake bike!

Not trying to put words in your mouth but I understand your comments to be that there are a couple of very specific Al rim and brake pad combos that are required to get equivalent braking performance of basically any disk, on any rim type (carbon or Al).

I don't know what your experience is riding disk on a road bike, actually. So far it sounds like not much--a parking lot is hardly exhaustive.

I'll take the feedback of ACTUAL expert bike rider's experience and opinion along with my own over the absence of data. But regardless, the lack of data doesn't prove your point. As you like to say, show me the data that rim bakes work better than disk...

Your confirmation bias comment is also ironic...

This is hilarious. I came from downhill MTB where guys crash with astounding regularity and I've never once heard of a problem with a disc (with huge 200-220mm discs too). Tons of theoretical arguments here that only sound good to people who have never used them

Fact is, braking strength, modulation, and consistency are worlds better with them. And that's what it all comes down to. Sorry that change makes everyone feel uncomfortable

Or I could ride my carbon disk wheels, with bigger tires, without having to switch to another wheel set, and it would still brake better than your Al rim.

But once again, please explain how you know this without having ridden a disk? I have both setups. Have raced both, and taken the feedback from guys at top level of the sport who have both. In other words, people who actually have hands-on experience instead of anecdotal opinions.

I don't see the big deal. No one is forcing anyone to ride anything.

I still have an 8 speed campy equipped road bike and I really would like to get back to the 8 versus 9 speed debate. I will restart it...

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Threadless headsets required new frames, but I don't see anybody arguing for a return to quill stems. Carbon frames had a learning curve, but they are now the industry standard. Every new gear added to a drivetrain has had its share of issues including "weaker chains, faster wear and tear, unnecessary new parts, being forced to ride 10 speed when my old 9 speed was just fine." Why didn't we just go from 5 speed to 11 speed? Who says we're going to stop at 11 speed?

Nobody is forcing you to buy a new frame. Professionals will get their new bikes for free. Some forward-thinking amateurs will adopt disc brakes when they inevitably get new-bike fever. Others will buy new frames with rim brakes because they don't know that it's the future. A few more will keep riding the exact same thing for years until they can't get replacement parts. Then they'll grudgingly be forced into buying what the market supplies, which looks like it'll be disc brakes or some derivative of that.

10 years ago, common knowledge was that most carbon wheels were "heavier, weaker, more expensive." Now everybody has a set, maybe two, and they get ridden over the cobbles at Roubaix. Until a few years ago, we didn't even know that lowering tire pressure by 10 PSI could actually make us faster!!

I'm not saying there aren't some short-term kinks to resolve. But this much is perfectly clear: Innovation and improvement can't all happen in a perfectly linear fashion, and it can't happen in a vacuum. There are known unknowns, and then there are unknown unknowns -- and somebody has to volunteer to figure out what those are. It's abundantly obvious that it won't be you, but please don't try to halt progress for the rest of us.

Exactly this.

We are still in the early stages od road disc development. we have barely gotten past the "slap some MTB brakes and CX wheels on a bike" stage. i have always noted two significant developments required to allow road discs to flourish - hydraulic brifters and UCI approval.

Now that both have occurred, you will begin to see new designs, better integration and new technologies developed. No one is saying the current gen products are the final answer, but a step along the way.

And part of product development is also failure.....it may prove that road discs are a trend and the final application is reserved for CX and gravel bikes. I personally hope to see hydraulic calipers end up being the "final" answer, but I am not betting on it.

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

How about HED's claims that their Jet Black rim brake surface reduces stopping distance by 25% in dry conditions, 70% in the wet, and is more consistent in all conditions?

If true, presumably the mechanism is that it lets an experienced rider better act as an ABS, riding the lock-up boundary?

Though I don't "feel" brake-challenged, I'd certainly consider such an advantage in rim surface if the performance could be corroborated. The ability to brake later is a huge advantage in bike racing, just like auto racing.

I'm hoping this whole disc brakes on road bikes pushes for further development to improve rim brakes.

As I mentioned earlier in a post, I have 10 bikes and 5 of them have disc brakes (Spackler, I have tonnes of experience on both), but I'm really not seeing the net advantage on a straight-up road bike.

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I mostly agree with your post, but would adjust the above to say that while there are distinct advantages, I'm not sure they outweigh the negatives at this point. Whether they do in the future or not is unknown.

*edit - just saw your "net advantage" wording. So yeah, we agree.

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Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams

What I'm saying is that there is data (and opinions) out there implying that there isn't as huge of a disparity (if any) between "best in class" rim caliper setups and road disc setups. I'm also saying that there is a dearth of actual, independent data saying one way or the other. Sure, confirmation bias goes both ways...which is why I'm asking for objective data. Makes sense, no?

My experience with disc brakes is more than just those hot laps on the Shimano setups at Interbike 2 years ago you keep talking about, and I'm pretty sure I've told you that already. I've also had extensive experience with Mavic Exalith equipped wheels, along with spending the last 2 months riding the Heds with the Turbine brake track. I also have experience in riding with a hydraulic rim setup for a few months. May I ask how much experience you've had with those technologies?

Oh yeah...I'm finding it hard to understand why you are implying that requiring "specific Al rim and brake pad combos" for best braking is a bad thing...isn't moving to separate discs doing the same thing, but then also requiring a whole new bike as well? Besides, Hed recommends just normal black brake pads for their Turbine equipped wheels, so it's not even special pads on that one ;-)

Seriously...spend some time with some Hed Jets or Ardennes wheels, and then couple them with a hydraulic rim brake. It may open your eyes...

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http://bikeblather.blogspot.com/

I've been on a set of the Jet 6+ Blacks and have put nearly 800 miles on them so far...and the braking is REALLY nice. Powerful AND controlled. I'm using TriRig Omegas and KoolStop Black pads.

I'd really like to see some braking test data on these...as I said above...

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http://bikeblather.blogspot.com/

The early results of the pro peloton testing of disc brakes:

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

I've been riding and racing disc equipped bikes for 12+ years and never burned myself on a rotor...

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feltbicycles.com - wilcouchatfeltbicyclesdotcom - Facebook

I've had the same experience, but I don't race in a pro tour peleton.

The crashes in pro tour races are more frequent, at higher speeds, and likely on more technical roads.

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Dang...is that from today?

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http://bikeblather.blogspot.com/

I'm pretty sure you haven't told me your experience and keep giving repeating that same reply.

I've has Ardennes + wheels for three years, on Shimano DA and Ultregra calipers as well as SRAM Red. Do they work fine? Sure. I also have Easton's new carbon race wheel, which paired with Black Prince pads, stops better in non-wet conditions. Is the Ultegra disk set up I have on Stans wheels superior? Yes, in my experience.

Your argument is against switching to a new brake/wheel system, yet you're advocating for certain "best in class" carbon wheels and hydraulic rim brakes to get the same performance as pretty much any disk setup. In other words, also changing a bunch of stuff, and in all likelihood at greater cost with less flexibility. I can buy a cheap wheel or one carbon one and it will stop the same in every condition.

I don't think anyone needs to run out and buy a new bike just because of disk's benefits (just like I don't need to buy new "best in class" carbon wheels and hydro brakes to stop), nor do I think that's the point. But when I'm ready for a new one it will def be that.

I'm talking about the models with the "Turbine" brake track. Those weren't available 3 years ago.

Although my experience with discs on the road isn't as extensive as yours, it has been enough to plant doubts in my mind...hence, again the call for actual data.

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http://bikeblather.blogspot.com/

you two need to meet up and ride each others bikes set up as you like. then you can come back and extoll on your experiences and if you are swayed one way or the other the least little bit.

or you can rent the movie, grumpy old men ;)

From his Instagram page yesterday. It was floating around twitter and made it over to Pez.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

But this much is perfectly clear: Innovation and improvement can't all happen in a perfectly linear fashion, and it can't happen in a vacuum. There are known unknowns, and then there are unknown unknowns -- and somebody has to volunteer to figure out what those are. It's abundantly obvious that it won't be you, but please don't try to halt progress for the rest of us.

Hey I'm an engineer. I'm not in the habit of halting progress. Rather calling BS on change and marketing masquerading as progress.

There are good reasons why disc brakes make sense on MTBs and CX bikes, which are absent when you look at road bikes. Same for tubeless tires. The positives do not outweigh the negatives for 99% of riders. You don't need to wave your hands about threadless headsets or carbon rims, as though all change is the same. It isn't. Not by a long shot.

The industry loves "new". It's nice if there is a new thing that is actually better, but even if it isn't, they'll see if marketing does the trick. What matters is perception, not reality. Lemmings jumping on the bandwagon.

The reason I care is because if the pros are on disc brakes, then that is what we will get also. Like it or not.

And BTW trail, racing road bikes is nothing like racing cars. The only time braking is important on a bike is tight switchbacks. And then, having a more "powerful" brake is only going to reduce hand fatigue. Even shitty calipers have enough power to endo or skid.

I'm opposed to disc brake development for road race/tt/tri bikes because manufacturers are spending resources in the wrong place. I want hydraulic brakes, and I want compounds and resins that modulate well and tolerate braking heat to be developed without adding drag from spokes and increasing loading on the fork. Or figure out how to bond a ceramic braking surface to a carbon wheel. There are a whole lot of ways to improve road bike braking that don't involve hanging more junk on the frame and make more engineering sense. They're more difficult to market though, and not as visually distinct, so marketing is driving companies away from that, which is dumb for performance applications.

Tom, you mentioned Pad contamination from road oils and I've seen that elsewhere like a GCN video where they suggest not having the wheels in the bike during washing because of this aswell.

Don't you think that in a peloton of 150+ riders, the improved wet weather braking that discs may provide will be effected by the road grime and oil coming off everyone else's wheels and getting on the rotors?

I don't buy that. I was thinking mostly about crit racing with corners sharp enough that braking is necessary. Which is a lot of like road-circuit racing in cars. The later you can brake, the better. Same in TT. If I can brake 0.1s later going into some turns, that's "free" time. It's marginal. But we do lots of things for "marginal gains."


Locking up is the problem that's being avoided, not the goal. Before ABS race cars could all lock up their brakes. But ABS was a game-changer. Because computer-controlled brake modulation allows braking right at the threshold of lock-up to a degree that was impossible for a human to do.

That's why I speculated on the modulation of the HED "black" surface. You can lock up any HED wheel just fine. So the benefit (if the claims are true) must be on the new surface providing more rider-feedback about an impending lock-up. A really bad brake is one that only has two states - free and locked. A better brake has more stages in between. The more "dynamic range" the better. And it's helpful to have a more linear response in pad-rim friction to hand-lever force. Vs. squeezing the lever and having a sudden (non-linear) transition from moderate friction to complete lock up.

That's ostensibly a benefit of disc brakes in cycling. Personally, I don't have enough experience with them to have an opinion. But I respect the opinion of those who do have that experience.

These things are testable without too much trouble! Someone just needs to do it.

I don't buy that. I was thinking mostly about crit racing with corners sharp enough that braking is necessary. Which is a lot of like road-circuit racing in cars. The later you can brake, the better. Same in TT. If I can brake 0.1s later going into some turns, that's "free" time. It's marginal. But we do lots of things for "marginal gains."

Do you actually race crits? If you are near the front where you belong you won't be needing brakes, and if you are farther back where you need them, your speed and brake application is dictated by the rider in front of you.

Locking up is the problem that's being avoided, not the goal. Before ABS race cars could all lock up their brakes. But ABS was a game-changer. Because computer-controlled brake modulation allows braking right at the threshold of lock-up to a degree that was impossible for a human to do.

I thought we were talking about discs vs rim brakes, not ABS.

And it's helpful to have a more linear response in pad-rim friction to hand-lever force. Vs. squeezing the lever and having a sudden (non-linear) transition from moderate friction to complete lock up.

That isn't disc brake specific at all. Whatever you are envisioning is better about the disc, can be done just as well at the rim.

The rim is actually a big disc. It was a stroke of brilliance in the beginning when someone discovered that the rim (that needs to be there anyway) works great as a brake rotor. Simple, light, effective.

Road grime doesn't have any affect on motorcycle road racing and they throw up a lot more grime than a bicycle.

It's a none factor.

Not every crit. But I like the technical ones, and in the technical ones, you need them. Even in the front. Watch the hands of Bahati in this one. And few in the business are better than him at "not braking."

Quote:

I thought we were talking about discs vs rim brakes, not ABS.

We're talking about your claim that road bike brakes don't need improvement, and your claim that because road brakes are capable of lock-up, that nothing more is needed. My counter-claim is that the ability to achieve lock-up is a necessary but not sufficient conditions for good breaking. ABS is an example where improve modulation provides enormous benefit over just the ability to lock up. It's an edge case. But I'm using the edges cases because you're making absolute claims which are relatively easy to refute.

Quote:

That isn't disc brake specific at all. Whatever you are envisioning is better about the disc, can be done just as well at the rim.

There are unbridgeable differences in design space. And some that are bridgeable, but not practical. The unbridgeable ones are the differences in applying a braking force near the wheel axle vs. at the rim. Very different - much more mechanical advantage to applying a braking force at the rim. You have to apply a lot more force at a "disc" to achieve the same effect at the rim. Seems like "advantage: rim." And it would be if the goal were lock-up. But - though I'm not an expert here - it's my understanding that the increased force "buys" increased "modulation range." Maybe you could get that same range on the rim, I don't know.


Yes, but there are costs. One of which is that your rotor material is the same as your rim material. And they serve different purposes. The lengths that wheel manufacturers go to (and the $$ we spend) to get serviceable carbon braking surfaces on the rim seems absurd to me.

Whether the costs outweigh the benefits depends on a lot of things. The balance of those things may be a no-brainer for MTB and cross. Debatable for "gravel," and far less certain for road. But making the final determination for road, I think, depends on truly characterizing differences in real-world performance between the two. And, afaik, no one's done that yet. So we're just taking dogmatic positions based on what we "feel."
I shouldn't say "no" testing. There's some wind tunnel testing. And a few "descending" tests between the two. But no real quantitative characterization of the two in terms of braking performance. Where are they different? How are they different?

I'm not talking about "in general." I'm talking about conditions where you have to brake to get below the adhesion limit. In many crits the optimal strategy for some corners is to brake. Even in the front. If you're going 35 in the straight and coming into a 180 turn where the adhesion limit of the racing line is ~20MPH, you'd need to coast for a looooong time to reach 20 MPH. The optimal strategy is to brake. Because it's a faster way to reach the finish line. That's what I'm talking about. I'm not talking about Cat 4's accordioning into a corner for no good reason.

It depends on what you mean by "not typical."

It's not all that atypical in my area. Manhattan Beach GP. Sea Otter crit course. Brentwood GP. That's just off the top of my head. All big-time CA crits with barn-burner straights leading into *very* sharp turns. Braking performance and skill is very much a part of those courses.

A statement and a question

The improvement I see is that while rim brakes have adequate stopping power, it requires significant input from your hands to achieve full force. This tends to increase rigidity in the limb (wrist, elbow and shoulder) which leads to decreased bike handling.

Riding my CX bike with road tires, I've noticed I can brake to the same level that I did with rim brakes, but with a more supple upper body and improved handling. I can better absorb imperfections in the road and race course.

I don't go down hill particularly slowly, However segments like this require you to go from almost 50 to under 20 for a hairpin corner:

Strava Segment: Down Sunshine - 8th overall.

Now, has anyone ridden the hydraulic rim brakes? I haven't heard much about them, maybe that says something.

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The above poster has eschewed traditional employment and is currently undertaking the ill-conceived task of launching his own hardgoods company. Statements are not made on behalf of nor reflective of anything in any manner... unless they're good, then they count.
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Effective lobbying of the cycling industry.

Yes it is???

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He who understands the WHY, will understand the HOW.

So rim brakes do not transfer torque to the fork, but disc brakes do?

"resist torque"? I thought you said you were an engineer? Holiday inn express last night doesn't count.

Try again. Draw the free body diagram. Account for all six dof's. Post the picture when you're done.

Now that you mention it the fork will need to be beefed up as well on a disc brake bike.

But I was talking about the wheel, not the fork. With a rim brake the wheel doesn't need to resist braking torque, but with a disc it does.

Holiday Inn? I don't get it...

Disc brakes do stress the fork more, hence the need for through axles.

Disc brakes are off to one side. Rim brakes are centered. Offset => twist => torque.

Disc brake calipers mount at the dropout. When you brake you the calipers pull on the disc, and the disc pulls on the calipers. With rim brakes this happens at the crown. Dunno if this is good or bad since the crown is already stressed.

Disc brakes tend to twist the wheel out of the dropout, which isn't usually a problem with rim brakes. We have learned some things from MTB.

The holiday inn joke is related to a series of commercials for the Holiday Inn hotels. When people stayed the night in the hotel, they gained a new skill

https://www.youtube.com/watch?v=SYw5eToTS5Y

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I'm so out of touch not having a tv. I recently learned that I've missed a lot of awesome Carl's Jr commercials. The internet caught me up, though...

Disc brake calipers mount at the dropout. When you brake you the calipers pull on the disc, and the disc pulls on the calipers. With rim brakes this happens at the crown. Dunno if this is good or bad since the crown is already stressed.

Offhand I'd guess it's not bad. The there is the force pushing the dropout back towards the frame, putting a bending load in the same direction on the crown. The caliper force is similar but in the opposite direction and with a much shorter lever.

Will the first iterations of disc brake road bikes/wheels be great aerodynamically and weight? No. Once a company makes a light/aero disc brake bike/wheel combination, someone will inevitably cite this thread.

However, to think that the first round of design will be the end all/be all is foolish and short-sighted. Unless the fastest (professionals) adapt new technologies you will not see the bike companies invest in the research and development necessary to make them better. From a design perspective disc brakes make sense as you now have components that serve ONE purpose, stopping the bike. Currently, wheel manufacturers HAVE to make compromises in order to develop wheels that balance weight, aero, and braking performance. There is NO such thing as designing a product that performs 2 distinct tasks perfectly. Disc brakes allow the rim to be developed to serve its purpose, keep the wheel in contact with the ground and be as light/fast as possible.

I am not one to support change for changes sake, but the evolution of biking is inevitable.

Cling to your 9-speed drive trains and call them superior. I'll grab my popcorn and watch how this disc brake thing shakes out in the pro-peleton and IF disc brakes become the de-facto standard in the pro-peleton, I'll begin converting as most others should.

Ummm, plenty of great engineering is having a component perform multiple functions. Yes, a single component may not perform two distinct tasks perfectly, but it may be a better solution than having two separate components. Yes, getting rid of braking on a the rim may increase the performance of the rim itself, but will it increase the performance of the wheel itself? Of the bike itself? Just looking at the wheel, the new wheel shapes, I do not see how getting rid of braking would make the wheel more aerodynamic, the shapes really do not care about the brake track. And you need to add more spokes to a front wheel, so now the wheel is less aerodynamic as a whole. And that is without figuring in the extra aero drag of the disk, sure you could make the disk more aero dynamic, but then you decrease the cooling of the disk. Sure you could make the disk more aero-dynamic, but then you have to figure out the heat issue, so you can add a bigger disk which will be heavier. This is even without talking about the caliper and its cooling. People keep talking that integration will solve this issue, but I am not sold on this because shielding the caliper from the wind is going to cause heat issues. When you brake you have a certain amount of energy you need to turn into heat. With disks brakes, you put this energy into a small amount of mass, which means the temperature is high. The bigger the disk, the lower the temperature at the end of braking. So to reduce aero drag, you may want a very big disk, so the caliper can be small and be very aero because it does not need much cooling since the temperature is low. Well at this point, maybe it makes sense to use the largest disk you have, the rim itself.

I think people in this thread that a less keen on disk brakes understand compromises very well. They are the ones asking if a possible improvement in brake modulation is worth the costs.

Disks may make sense, but right now there is nothing

Fully understand and agree with what you are saying with the back/forth between the pro and amateur racers. You make a very good point that the pro's are not ALWAYS on the fastest gear, simply because their sponsors want them on the companies gear. However, I do feel like bike companies have a vested interest in their bike winning tours/stages/races, so they will invest in refining the design for racing.