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

Hi Xeno, Let's cut our losses as you will _never_ read any reference I've provided.

I provided, what, oh, maybe about a dozen reliable references that back up my point of view, and you provided, oh, um, what? Zero, right?

You think I didn't know that was going to happen, oh, maybe a decade ago? There's a reason I said that we own the intuition of monkeys, Xeno.

And there's a reason I said that this intuition is a terrible thing indeed. People who trust only in their intuition are only right by pure chance.

It's people who trust in facts who are right more often than they're wrong. And you don't want to see any facts (you didn't even _read_ them, in fact).

That means it's impossible to carry on an adult conversation with you on this topic. It's like asking someone to stop believing in the Easter Bunny.

Let's just leave it at that because I can provide ten thousand factual references that the earth isn't flat and there will _still_ be people like you and Steve and Alan Baker who will emphatically claim it _is_ flat.

Not only that it's flat, but they'll find some 30-second YouTube video of a twelve year old kid in NJ who, with just a yardstick, "proved" it's flat.

So let's cut our losses. You think the earth is flat, and you have Alan Baker on your side. Steve too.

All I have on my side is every reputable brake expert in the industry. I won't provide you with any more facts because you don't want to see them.

I have real world experience with disc brakes on my side, that's enough!

And it also can cause shimmy without pulsations or judder. That I have definitely experienced and on my own car.

A lot of people, when doing diagnosis, cannot differentiate the symptoms. At the end of the day, the process of *measuring* and

*machining* clears up beyond any shadow of doubt as to what the problem is.

You do know that cast gray iron _melts_ at about 2,300°F, right?

"To get cast iron hot enough to soften the metal you'd need to generate almost 2,300°F range. There isn't a factory stock automotive brake system in the world that's capable of generating that kind of heat. In fact, you would experience brake pad fade, pad disintegration, brake fluid boiling and rotor discoloration long before you reached 1,000°F."

And, let's be clear about the boiling point of brake fluid, Vic.

DOT 3 >401°F (new) & 284°F (1-2 years old) DOT 4 >446°F (new) & 311°F (1-2 years old) DOT 5.1 >500°F (new) & 356°F (1-2 years old) DOT 5 >500°F (new) & 356°F (1-2 years old)

Having said that, you do realize the test disks used in that experiment were not "normal" in that the prior heat treatment was for five & ten hours at 1,076°F and then furnace cooled to 572°F at the rate of 104°F per hour for about five more hours, and then air cooled to room temperature for a few more hours _before_ testing on the dynamometer, right?

*How often do _your_ brake rotors spend ten hours at a thousand degrees?*

They tested those cast iron rotors under those rather extreme conditions because they were scientists & engineers who were studying the effects of various manufacturing conditions for improving cast materials, and because they were interested in crafting what they called a "prescreening process" for disk selection at the early stages of brake system development.

It's almost certainly good science, but it's not a real-world test, Vic. HINT: _A brake system would be marshmallows under those conditions._

Good video

Andy Burnelli/Arlen Holder/Dean Hoffman/Nil/Robin Goodfellow/more is wrong of course™.

Those look like pretty thick rotors. The warping had to be pretty minor in order to machine them flat. Most of the rotors these days are too thin to machine and are just replaced as part of brake job.

There is one train of thought that turning sufficiently thick, flat, non-warped, rotors, is unnecessary and that after a short while the pads will break in to match the minor imperfections in the rotor, with just a little extra wear on the pads. "If your rotor surface is smooth there is generally no need to have them turned. If, however, you have warping, or rough spots they should be turned, or replaced if need be. This is easily detected if you have a solid, non-pulsing braking action when you press down on the pedal,"

.

People like Steve are no different than people who believe the earth is flat. Steve actually _believes_ what he writes.... and yet... And yet... and yet... Steve doesn't even _read_ what the experts say about it.

As a result, Steve will _never_ (ever!) find a reputable expert to back up his claims that the earth is, dammit, flat.

But... he can _always_ find a salesperson selling bullshit to back him up. Which is what Steve did in this thread (and with his four URLs):

. Notice Steve can't find even a _single_ expert backing up his claims that the earth is flat simply because he found people who said so.

Below is what Steve is completely unaware of (it's from _all_ the experts). ==================

*Warped Rotor Myth Training Video, by Raybestos Brand Brakes* Many technicians will diagnose pedal pulsation as warped rotors. Let's dispel that myth right now. *Rotors do not warp.* *To warp a rotor you physically have to change the* *metallurgy of that rotor. To change the metallurgy* *of a rotor, you're running in excess of 2,300 degrees.*

_There is no brake system that runs 2,300 degrees._ ==================

"To get cast iron hot enough to soften the metal you'd need to generate almost 2,300°F range. There isn't a factory stock automotive brake system in the world that's capable of generating that kind of heat. In fact, you would experience brake pad fade, pad disintegration, brake fluid boiling and rotor discoloration long before you reached 1,000°F." ================== Let's be clear we're "mostly" talking cast iron rotors here:

1. cast iron (2,300°F)
2. steel
3. stainless steel
4. laminated steel
5. high carbon iron (e.g., Sparta CX3.5)
6. ceramic

And, let's be clear about the boiling point of brake fluid.

DOT 3 >401°F (new) & 284°F (1-2 years old) DOT 4 >446°F (new) & 311°F (1-2 years old) DOT 5.1 >500°F (new) & 356°F (1-2 years old) DOT 5 >500°F (new) & 356°F (1-2 years old) ==================

*Stop the "Warped" Rotors Myth and Service Brakes the Right Way* Rotors are cast in extreme heat at three to five times greater than the most aggressive braking situation. Physically 'warping' a rotor would require a similar application of extreme heat, which is impossible." ================== *The 'Warped' Brake Disc & Other Myths of the Braking System* "In more than 40 years of professional racing, including the Shelby/Ford GT 40s - one of the most intense brake development programs in history - I have never seen a warped brake disc." ================== "By declaring a customer's brake pedal pulsation complaint is caused by warped rotors is like saying the earth is flat. Both are cases where the observation of the person is based on a tiny piece of evidence that is false in nature and application." ================== "Brake rotors do not warp from heat, even when driven by the most aggressive traffic officer." ================== *The Mystery of Warped Brake Rotors* "Contrary to popular belief, brake rotors, and especially brake rotors supplied by a reputable manufacturer such as DBA don't warp, no matter how aggressively a vehicle is driven. Yet, as we know, brake pedal pulsation caused by out-of-true brake rotors is a fairly common problem that is almost invariably attributed to warped rotors, which is almost invariably confirmed by excessive amounts of rotor run out that is easy to "prove" with a dial gauge." ================== *Why Do Brake Rotors Warp?* "The thing is, rotors don't actually permanently warp. It may feel that way when braking, but what really happens is that they become irregular due to excessive lateral run out of the rotor face. You can feel through the brake pedal as little as .002" of run out. This amount of run out is far smaller than you can see. In other words, rotors always remain true, but they can wear out irregularly for several reasons."

1. Lug torque
2. Hub rust
3. Hub runout ==================

*Brake Rotors Warp From Heat -- Myth Busted* "there's simply no way that a brake rotor can get hot enough to warp or deform on an ordinary passenger car." ================== *Nuts & Bolts: Warped Rotor Myth* "It's exceedingly rare to actually warp a rotor. Instead, the cause of the shudder you feel through the pedal is an uneven buildup of brake pad material on the rotor itself. As little as 0.0004 inch can be felt through the pedal & 0.001 inch can be downright annoying" ================== **Everything You Need to Know About High-Tech Rotors** "The most persistent myth about rotors is that they warp. It takes a lot of heat, the kind of heat used in the casting process, to actually warp a rotor. The two common problems that cause pedal pulsation are lateral run-out and disc thickness variation. Lateral run-out is typically caused by run-out from the hub face, wheel bearing, uneven lug nut torque, or a buildup of rust and corrosion between wheel and hub. Disc thickness variation is most often caused by excess pad transfer, the very thin layer of pad material that bonds to the rotor surface, and uneven wear from an improperly mounted caliper. " ================== *Warped Brake Rotors - Vibrating Reality or Internet Myth?* "Traditionally, this was blamed on warped rotors, and the prescription was to either get the rotors machined or to replace the rotors. Technically this wasn't wrong, but it's not completely right either. To understand what is going on, lets examine how the brake pads and rotors interact. It's not as simple as it seems on the surface, and relies on complex interaction between friction materials. Technically yes, the rotor is warped because the buildup of pad deposits is a few thousandths of an inch thick. To restore proper smooth braking performance, the uneven deposits need to be removed, and a fresh uniform layer of friction material needs to be laid down." ================== *Stop the "Warped" Rotors Myth and Service Brakes the Right Way* "Myths take hold ­because either A) they seem completely logical or B) they are so often repeated that they just become common knowledge. The warped rotor myth is a little bit of both. A rotor that contributed to a pulsation condition certainly appears 'warped.' Plus, everyone says it - even technicians that know the rotor isn't really warped will say it as shorthand. Rotors are cast in extreme heat at three to five times greater than the most aggressive braking situation. Physically 'warping' a rotor would require a similar application of extreme heat, which is impossible." ================== *Six Brake Rotor Myths Debunked* Brake Rotors Warp - Rotors don't warp. Back in the 1970s, in what was probably a scene right out of the movie Dazed and Confused, someone came up with a theory about brake-rotor "warping," and it totally stuck. Why? Probably because, in layman's terms, it makes sense. But then real life happens and this faulty explanation doesn't hold up to scientific scrutiny. What is often described as "warping" is actually the presence of two separate phenomena that can happen in isolation or in combination with each other, and neither has anything to do with warping. These phenomena are: a. Brake torque variation (BTV), and b. Disc thickness variation (DTV) ================== *The myth of warped brake discs* "Have you ever heard someone say they had warped brake discs? Typically someone had the discs resurfaced to cure the problem and after a relatively short time the roughness or vibration came back. In almost every case, this problem is not caused by a warped discs, but that the brake pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation or run-out due to hot spotting that occurred at elevated temperatures." ================== "Calling it brake rotor warp demonstrates a complete misunderstanding of the metallurgy and the braking process" ==================

Empiricism trumps your bullshit, Arlen:

'In the past people here have said that rotors don't "warp". That shaking or shuddering during braking is caused by brake pad deposits. This is on my lathe right now. You can see the spots where the bit is not even touching the rotor. Definitely NOT pad deposits. The bits are missing the rotor on opposite sides like you would think it would if a rotor was warped. Thoughts?'

You didn't have to tell me that. I knew it.

Your real-world experience is very helpful sometimes. As it was with the tire wear on mountain roads.

I appreciate that. I won't delve further on the brake rotor warp issue.

Because you lack the integrity to admit you were wrong.

f you're so certain about that why not offer to pay parts and service charges for a warped brake rotor?

Where "reputable" is redefined as "agrees with me".

Very good question.

:-)

If that's supposed to be a question, I readily admit I don't know what you're asking.

Can you please rephrase the question so that I can understand what you're asking me to respond to?

Thanks!

And he's not just suddenly playing dumb, folks!

Yeah, that's been the trend for quite some time now. Rotors are considered as *disposable* as the pads themselves.

Indeed, I need to see a very overt issue before I would bother machining rotors. If you don't feel the symptoms on a road test, measurements look ok and the surfaces aren't gouged, I just fit pads, then do a bed in process

Yep, very familiar with that scenario. Been there, seen that, done that!

;-)

Hi Xeno, On _that_ topic alone, have you ever seen a typical rotor "gouge" spec? I have.

That spec is often hard to find, but when found, it's shocking (to me). For two reasons.

The first is that the spec allows _huge_ gouges (imho). And the second is I've never seen a rotor _that_ gouged.

No big deal. I'd junk any rotor that doesn't meet spec w/o a second thought since a rotor is a safety item that costs only about $15 to $35 per wheel.

While I'm not saying gouges can't happen, I've _never_ failed a rotor on its gouge spec in my life (however I only replace my own rotors of course).

My question to you are the two above: a. Have you seen how (seemingly) huge a gouge has to be to fail spec? b. How often have _you_ seen a rotor gouged enough to fail that spec?

We can certainly see what you wanted to change the topic.

Hi Xeno, (See the question in the bottom of the introductory explanation below.)

A _lot_ of morons (like Steve) "claim" to need to replace rotors with every pad change, and even more morons opine that they simply replace rotors at every second pad change, and even more morons than those prevalent types, ask on the car forums the dumbest question possible, which is Q: *How do you know when to replace your rotors?*

The reason all those three are the brain child of morons is that you replace a rotor when it no longer meets the spec, and, as you note below, the spec contains a few simple components, _all_ of which require tools.

Just as Dunning & Kruger wondered what made the bank robber think the lemon juice would work, and just as I wonder what makes iKooks believe their fabrications of functionality would work, I have wondered for years why people ask the dumbest "what oil" type of questions on car forums.

Over the decades, I've realized the "what oil" questions and the when do I replace rotors questions are born of the exact same "Steve" mentality.

1. They don't know the spec, and,
2. They don't own the tools to _measure_ to the spec.

It's really that simple, don't you think? Q: When do you replace rotors? A: When they no longer meet the spec.

Q: On rotors, how do you know when they no longer meet the spec? A: You measure them.

Q: What tools do you need to measure rotors? A: The most often missing tool is a dial gauge with a good sturdy mount. The second most often missing tool is a simple one-inch mic. The third most often missing tool is a gouge depth and width gauge.

The tool I don't yet own is the latter (as I've never needed it). So I use a coin of the correct width but that's not the "right" tool.

Q: What tool do _you_ use to measure the depth and width of a gouge? A: Xeno?

Given rotors cost about what it costs to machine them (and, in my last clutch replacement, flywheel machining was $60 while a brand new flywheel was only about $80), I have never bothered to have _my_ rotors machined.

However, I've also never taken a car to a mechanic in my life for something as trivial as a four wheel brake job, which is just about the easiest job anyone can do at home if they have the most basic of the simplest of tools.

The bed in process is critical in terms of what people call 'warp' (which is simply that the car does funny things, which I won't call 'shudder' or 'judder' or 'shimmy' or 'pulsations' since people call _everything_ "warp".

However, that bed in process takes an appreciable amount of time, especially in areas like those where I live where the highway is nowhere near, and it's jam packed during all hours of the day with traffic.

My question to you, Xeno, and to any others who get brakes done by the professional mechanics, is this simple but very important question:

Q: Do professional mechanics take the car on a drive to do proper bedding?

This text does not exist in the post to which you're replying, Arlen...

...so now you're just a liar.