re: "Google Wallet may be making a return" (and "Why is it so complex

Differential thermal expansion does not require entering the plastic zone for the entire piece.

Finally someone on this newsgroup is using their brain.

It's disconcerting that most people completely ignored the dozen references I provided and that they provided, in turn, a 20-second youtube from a kid in NJ which shows absolutely nothing whatsoever - and yet they think it does.

They may as well claim the earth is flat in a 20 second video from a kid in NJ who _proves_ it beyond any doubt in their (strange) low-IQ brains.

Anyway, Amuzi brings up an _excellent_ point that you don't likely need the

2300 degrees it takes to _begin_ melting a typical cast iron rotor.

But bear in mind even the best brake fluid boils off at well under one quarter of that temperate, and that the rubber in the braking system would be marshmallows anywhere near the "zone of thermal expansion" Amuzi alludes to, and we have what appears to be a situation which requires more data.

At what temperature does a rotor 'soften' is key here, I think, isn't it? Isn't that what Amuzi is alluding to?

Certainly if you leave the rotors on a steel rack at a thousand degrees for ten hours (which we learned in the paper Vic Smith referenced), they will "increase" their "distortion"; so I _believe_ what Amuzi is alluding to.

However, nobody here is going to claim that their rotors spent ten hours at a thousand degrees and _then_ they declared that they warped, right?

The brake system components (piston gaskets, fluid lines, fluid, etc.) would be marshmallows at even the "low" temperature of a thousand degrees.

In summary, I get it that people _believe_ their rotors warped, and yet, I've _never_ seen anyone who said that who actually _measured_ it, and, worse, I found a dozen experts who claim it's impossible given the temperature required is greater than the brake system can handle.

If Amuzi is correct that warp (aka "thermal distortion") happens at a lower temperature than a thousand degrees for ten hours, then I'm all ears.

Give me a fact, and I'll read it. Does anyone have any reliable cites that back up their belief system?

How about videos of warped rotors?

Will those do?

I realized belatedly that I didn't point out that the temperature it takes to "soften" rotors only has to be "locally" applied for what Amuzi is hypothesizing to occur, to occur.

So, for example, you can perhaps get to the 2300 degrees it takes to begin softening rotors locally, but bear in mind rotors are _designed_ to cool off, so it's not going to be easily done, if it's even possible to be done.

I get it that almost everyone trusts their intuition more than they will ever trust in facts, where I repeat I know Quantum Mechanics, where _nothing_ is intuitive. Trust me on that.

We humans own the intuition of monkeys. That serves us well sometimes - but it serves us poorly most of the time.

The reason it serves us poorly is that, sure, it "sounds good" that rotors would warp, especially when most of the time replacing or machining the rotors "solves" the warp, so, to most morons, it's intuitive it warped.

But the facts remain that you need an astoundingly huge temperature, whether applied locally or not, to force a rotor to deform like that.

The brake system can't handle that temperature.

There are a few reasons for that, one of which is it never happens, but the more important reason is that the system is _designed_ to cool itself off.

What I'm fighting here is the fact I'm not used to dealing with the hoi polloi who believe in a 20 second YouTube video of basically nothing, without even _reading_ the dozen or so reliable reference links I cited.

I'm not saying Amuzi is wrong, by the way - since his premise is valid that locally, the deformation temperature point might be reached in a typical braking system under duress...

But what we need now is _science_ backing up his supposition. If you post it, I'll read it.

More to the point, as with Vic Smith's reference, if I read it, I'll at least grasp what it says (using basic adult cognitive skills God gave me).

Metals don't need to "soften" to undergo change due to relief of stress.

Brake pads are thermal insulators so whatever is going on at the rotor doesn't necessarily melt rubber bits or boil brake fluid. There's also ample airflow and space between rotor and other components. Even brake shoe holders have minimal contact with calipers.

Also, out in the world, boiling brake fluid is virtually unknown but warped rotors, while not commonplace, are regularly noted in brake service.

further to my recent comments:

Note relatively significant heat isolation of rotor braking surface as compared to caliper, brake lines, wheel bearing etc.

<snip>

Exactly. The idea that brake fluid would boil because the rotors got hot displays a profound cluelessness about how vehicle braking systems function.

When people say *trust me*, it is far wiser to do the opposite.

You might, I don't. One of the things I do is *test* any *theory* I come up with. Is the rotor warped? Intuition might tell you, my measurements tell me what the reality is *on the ground*. I spent decades teaching apprentices to *test* any diagnosis theories (or intuition) they come up with. Never assume, just measure.

But to us *mechanics* who actually *measure the warp*, it is no longer

*intuitive*, it's *proven fact*. Facts are good.

Rotors never heat *uniformly*. In fact, it is the outer periphery that will heat the most and it is the outer periphery that will begin to deform first.

Well done, and the cooling is *never even*.

I don't consider myself to be a member of the hoi polloi and, in direct contrast, I have seen and measured many such warped rotors as depicted in the video. And, as in the video, I have *machined* countless rotors

*with warp* and measured, seen, heard and *felt* the same effects as shown in that video and so many others.

You screwed yourself on that last sentence.

You are being deliberately disingenuous here! I have told you that I have *measured* warped rotors. It is very easy to prove that a rotor has warped, all you need is a dial indicator with a magnetic base. You measure the face and find the *low point*, mark it. Then you find the

*high* point, mark it and include the measurement. Use zero as the reference datum for the low point. Then measure the obverse face of the rotor in the same manner. If the zero reference on one side matches the high side on the obverse, you have a *warped rotor*. You can do further checks to ensure that something else is not causing the effect, the dial indicator will serve for that purpose as well.

BTW, have you spent *any time* in an engineering shop at all?

Irrelevant to the situation that occurs in a brake rotor. You are making incorrect assumptions, bullshit assumptions in fact.

I have given you facts, they don't match your *belief system* so you diss them out of hand.

I have been there, measured warped rotors. Your voodoo science doesn't match the *reality* in which I live. That is a problem for you, not me.

It's kind of interesting how _desperate_ you have become given not a single one of you read even a single one of the references already provided.

All you "can" do is point to a special Porsche destructive testing jig.

You do realize that rotor was run on a special test jig that purposefully ran at a simulated speed of 150 mph continuously with the calipers locked.

The pads were destroyed. The rubber was on fire. The fluid boiled. The rotors were cracked.

Just as the references said they would be.

Think about the _logic_ here, in your _desperation_ to back up your imaginary belief system.

If you can't get rotors _that_ hot without _tremendous_ damage to the braking system components, how do people who claim their rotors warp "justify" that their pads and fluid and rubber is just fine.

Doesn't anyone here own a synapse that can explain that obvious fatal flaw in their argument?

Find even a _single_ reliable reference that backs up your claims.

And I'll read it.

Find just one.

I can tell you're getting desperate because you have no defense to facts. You're acting just like Putin where you accuse me of what _you_ are doing.

FACT: a. I gave you a dozen reliable references; none of which you read. b. You gave me zero.

Who is being disingenuous here, Xeno. a. I backed up my claims with reliable references. b. You didn't.

But you can turn me around on a dime. I'm easy to convince with facts.

Just "saying" you measured warp isn't going to work since I've heard people say that for decades and not one of them ever knew that the temperatures required would turn a braking system into mush.

Provide me even a _single_ reliable reference that says what you say, which is that people "think" rotors don't warp and yet they do. *Find just one*

Without even a _single_ reliable reference backing up your claim, it's you who is being disingenuous. Not me.

Note: I am well aware you can find a billion bullshit web pages selling new rotors that will "claim" the rotors warped so find a _reliable_ cite, like I did, from _experts_ who aren't selling anything but just telling the facts.

Remember, a rotor will crack before it will warp.

Me? Desperate? You must be joking? FWIW, Putin is a *liar*.

I gave you the one I value most, my direct experience.

I backed up my claim with reference to what I saw and did whilst working at my trade. My direct experience. Yes, I worked in the industry and have *hands on* experience with warped rotors. I have seen them, I have measured them, I have, where possible, even cleaned them up to serviceable condition. Your *experience* with brakes is limited to hobby repairs at home.

Um, no you're not. You ignore facts that disagree with yours.

Then you do not understand what goes on in braking systems in the real world. The rotors I have seen and measured did not warp because I gave them a *dark look*.

A saw with my own eyes and measured with my own hands numerous warped rotors.

Um, not always. I have seen plenty of rotors that were warped with no signs of cracking. I have also seen the converse, cracked rotors with no signs of warpage. It's a *different effect*.

The only spec, ultimately, that matters is the minimum thickness spec. If the rotor won't clean before minimum thickness is reached, any gouge spec becomes irrelevant. I'm not going to put a machined rotor back on a customer's car if *gouges* can still be seen on it - regardless of what any gouge spec says.

*I rest my case*! My brake work has always been for *customers* and, as such, I place a high standard on it. You want to reuse a rotor I deem too gouged, you will find yourself doing the job for *I* won't touch it. It's called *responsibility*, perhaps you've heard of the concept?

No matter who you are, "my own experiences" is not a reference, much less a reliable one.

A reference is something published and accepted by others, preferably through an editorial process that includes exports in the field. It is not some guy saying "this is my experience" even though that might be useful in some cases.

About the only exception to this is pure math where you can demonstrate a proof, and even there when you apply those numbers to real-world problems you may still be doing it wrong.

Here's an example that might relate to you and help you understand.

In the US, there was a problem with aluminum electrical wiring in homes, and the use of aluminum wiring in new construction is banned because it is too easy for it to cause house fires.

Now, some people will decide that "ZOMG! This house has electrical wiring that is aluminum, I have to rewrite the house before it explodes!"

An experienced electrician will tell you that, yes, you should probably rewire because it isn't safe.

The same electrician will go home to his/her house with aluminum wiring and will not lose a second of sleep.

Why? Because the electrician knows from experience that aluminum wiring is only an issue if incompetent nincompoops (like home owners) f*ck with it and don't know what they are doing.

But no electrician is going to cite their personal experience with aluminum wiring, or point out that there are plenty of ~70 year old houses with aluminum wiring still out there not catching on fire, because personal knowledge and experience is not a reference.

If you want to argue about something, you need to be able to provide actual references.

All of that said, in this case you are wallowing in mud with a shit-covered pig on his home turf, all that will happen here is that you are going to smell like a pig covered in shit and the pig you are arguing with is going to be very happy. VERY happy.

Please, every time you're going to reply to him imagine that little chubby he gets and think again. Do you really want to be responsible for the only sexual stimulation that obese naked troglodyte gets in his life? Please, think of that image first.

Indeed but Arlen says warped rotors don't exist, I say they do because I have seen them, I have measured them, I have machined them. There are video references showing *warped rotors* so they do exist.

The maths involved is above my pay grade. ;-)

I have seen the same incompetent nincompoops dick with vehicle wiring that they simply do not understand. Had a friend show me a heated and

*melted* headlight socket and said it was caused by a *short*. Didn't understand enough about electricity to see that a resistance causes a voltage drop which, in turn, generates heat. What he was looking at was the after effects of a bad connection in a relatively high current environment.

No experience with aluminium wiring because, as far as I am aware, it isn't legal in this country. I can imagine scenarios where incompetent nincompoops can right royally screw something like that. I have a name for people like that - Crayfish - the meat is in the tail, the shit in the head!

It's a stark image you paint there! ;-)

Why did you concoct that purely imaginary fanciful strawman above Xeno?

I wonder if you own the cognitive skills to realize you just proved my case and, at the same time, you proved that you can't comprehend basic facts?

Basic facts that you can't seem to comprehend: a. I said I junk a rotor (of my own) that doesn't meet spec. b. I said I even sometimes junk a rotor (for others) that meets spec. c. Better yet, I've said many times I've never seen gouges on those rotors. d. And better still, I call the manufacturer to _get_ the rotor specs.

From those four stated facts, you comprehended _zero_ of them. Why did you miss _every_ fact?

I don't know why. I suspect you're desperate.

Like Alan Baker, you're desperate to _ignore_ all facts. You're desperate to try to find any way around all those facts.

You're so desperate, you won't even _read_ what the experts say.

In your desperation to ignore facts, you actually _concocted_ an imaginary situation where I allowed gouged rotors to remain on the vehicle.

Let me ask you a simple logical sensible question please, Xeno. Is it _possible_ to have an _adult_ conversation with someone like you?

My observations (based on the facts), Xeno:

1. You strongly believe in what experts say is a common myth, and,
2. You completely and totally ignore all facts from those experts, and,
3. You believe only in a 20-second video from a 12 year old kid, and,
4. in the end, you are desperate to concoct a strawman that was never said.

Why did you concoct that purely imaginary fanciful strawman above Xeno?

I'm willing to listen to and read and watch "good science"; but I must first let you know that I'm allergic to people trying to bullshit me.

I'm all about good science, where I appreciated that Vic Smith brought up that engineering test article which shows there "can" be deformation; but unfortunately, that deformation came after ten hours at a thousand degrees.

A car brake system would be mush after ten hours at a thousand degrees.

If you can find even a _single_ reliable expert in the field who can back up your belief system, post the reference and I'll read it. But please stop it with the 20 second videos from a 12 year old.

If you can't find even a _single_ reliable reference from experts in the field, then that alone should tell you what you won't believe from me about your strongly held belief system.

I recognize that people hold onto belief systems that have absolutely no basis (otherwise, religion wouldn't exist, for example), but if you're going to try to discuss rotor warp, and yet, if you're going to ignore a dozen reliable cites, then at least provide a reliable cite of your own.

What Amuzi said is certainly an interesting hypothesis... what we need to explore it further is good solid references that back up his hypothesis.

Does _anyone_ out there have a _single_ reliable cite to back up the hypothesis that Amuzi proposed to explain how rotors can commonly "warp" when the temperature that is required would make the rest of the braking system boil & seals would disintegrate before rotors could get to even one quarter of the required temperature.

In summary, if you don't believe the dozen references I provided, then you're not going to believe a thousand more from me; so it's up to _you_ to provide a reliable reference.