On Sun, 14 Jan 2018 17:52:27 -0800 (PST),
I agree with you that the primary role of friction material is their
friction, but as the AMECA engineer told me, the way they outgas alone can
have an effect that is huge, as you are also noting.
It would be nice to figure out what these second-order effects are, such as
outgassing as mentioned by the AMECA engineer, as the police cruiser test
already eliminated any second-order effects from a difference in vehicles
since they tested the different pads on the exact same vehicle.
So we can tentatively state that you are 100% correct that second-order
effects (outgassing) apparently are as big as first-order effects
The AMECA engineer said that all materials heat up differently, which, he
said, also effects the performance of the pads.
So I think we have two potentially high second-order effects which are
(shockingly) almost as important as the first-order effect of friction
1) outgassing (outgasing sp?)
What other potentially very high (as high as friction) second-order effects
could we have, when we've eliminated the difference in vehicles and driver?
On Mon, 15 Jan 2018 14:19:45 -0000 (UTC), Mad Roger
Pad vibration - which has an effect on gas venting, counterd by the
effect of reduced pad contact
May not be a HUGE difference, but it is possibly a factor. Also heat
CONDUCTANCE - metallic pads conduct more heat to the caliper than
ceramice - making the boiling point of the fluid more critical (if
running metallic or semi-metalic pads you want to be sure to be
running DOT4, not DOT3, and you want it freash and dry) One reason
Chrysler was using composite pistons for several years in the early
no-asbestos days (until they found the pistons swelled and stuck - - -
They used to be a bitch to get out.
To Madman: When I was early in emergency services I used to run my private
vehicle. I had to pay attention to braking because after 3 stops there were
NO brakes. I got the police shoes because I was all into it. What a
difference! When I got a pursuit certified vehicle it was wonderful. They
are designed and built to endure punishment. Try and go to the dealer and
get the model, good luck with that. Watch what happens on one of the police
shows. See which car is destroyed or smoking at the end. The actors can't
make the corner because they got no brakes. Or the engine expires. Something
is to be said when one goes from 0 to 40 then 40 to 0 repeatedly and sit
there idling for the next 1/2 hour then going to the next call. Then there
were the ambulances and fire trucks. *Training*
On Mon, 15 Jan 2018 17:01:47 -0500,
I've never experienced such fade in my life, and I drive a performance car,
where I've driven down many a long hill. I don't know why I have never
experienced brake fade, but I know it exists. I just have never felt it.
But I've never put in less than FF pads either.
That may or may not be related - we can't tell. It's just a datum.
What's a "police shoe"?
The police report from Michigan tested "regular" shoes only.
If there was a difference, it's hard to tell because nobody (except the
police in Michigan it seems) tests *new* pads against *new* pads (after
You probably didn't as nobody does.
You probably tested *old* pads against *new* pads, and even if you did test
apples to apples, it's not extensible to "my" car or to anyone else's car.
That's the problem with tiny experiments of a single datapoint.
What the heck is a "pursuit certified vehicle"?
I drove an EMT vehicle many times. It drove like a truck.
Like any performance vehicle on the road today?
Don't even know what it is.
Is it a souped up police cruiser?
That's not a good scientific test.
I have been trained to drive an ambulance.
Know what they taught me?
a. Defensive driving
b. Noise pollution is bad
c. Laws (nobody is allowed to break the law in that state, not even
I think in some states emergency vehicles *are* allowed to break the law,
but not in that state where I drove the ambulance. Of course, nobody is
going to give you a ticket either, but if you kill someone while breaking
the law, the onus is on you.
On Tue, 16 Jan 2018 02:10:28 -0000 (UTC), Mad Roger
The shoes they tested were premium and heavy duty (all of the FF and
FG were "heavy duty" pads.
On Persuit rated vehicles they oftern also have larger rotors and
drums - as well as different tires, and even different RIMS to allow
bwtter brake cooling. Never wondered why cruisers have "dog dish" hub
caps instead of full wheel covers??? To allow the brakes to "breath"
I can say without reservation that the "police duty" and severe duty
brakes were MUCH better at high speeds than standard brakes (and
sometimes not nearly as good when cold/low speed) 1 1966 Dodge Polara
Pursuit Special I drove for a short time went like a scalded cat, and
stopped like you had jammed a stick into a hole in the pavement.
Todays persuit special vehicles are often the big ecoboost engine on
fords, and Hemis on Chargers. Often with a "special tune" that raises
the rev limiter setting and reprograms the tranny shift points - as
well as having bigger rads, bigger alternators, honking big sway bars
and super-duty shocks and springs.
Then you have been poorly trained. Our company had mandatory EVOC (Emergency
Vehicle Operations Course) training by a certified instructor &
recertification. PA is a "due regard" state. Look it up. You can't help if
the vehicle is crashed. You are responsible for the crew and victims.
On Mon, 15 Jan 2018 12:23:01 -0500,
Clare Snyder wrote:
That makes sense that the outgassing of pad A can be vastly different than
that of pad B, and, in fact, they "burnished" the pads in the police test
to minimize the initial presumed-far-greater effect of that as the
adhesives heated up for the first time and vented gases.
Occam's Razor logic tells us that only one of 2 things is happening:
a. There is a huge as-yet-unnamed second-order effect, or,
b. There is a combination that results in a huge second-order effect.
That there is a huge second-order effect (after friction), there can be no
But what is the 2nd-order effect's cause and can we test for it?
Two Occam's Razor points on that observation above, which is correct.
1. While this vehicle specs DOT3, I'll put in DOT4 instead.
2. Metal versus semi-metallic versus ceramic is marketing bullshit
I know there are no laws that differentiate between metal, ceramic, and
semi-metallic - as I've personally spoken to the people who make the
Axxis/PBR/Metalmasters pads. They told me it's all bullshit only they said
it far more politely and less succinctly than I just did.
Suffice to repeat that a spec of dust makes a pad ceramic, just as a spec
of iron makes it semi-metallic.
I posit marketing came up with these wonderful good/better/best number-line
decisions for people since people (like Terry Schartz seems to be) want a
simple number line instead of those oh-so-very-complex quality
Where's Jeff Liebermann when you need him!!!!!!!!!!!!!!!!!!!! :)
On Tue, 16 Jan 2018 02:10:28 -0000 (UTC), Mad Roger
Most definitely is NOT marketing Bullshit. It is solid engineering
You speak mandarin, do you?
There may not be "legal" definitions, but there are industry accepted
definitions - and I've sent you numerous referencesthat spell them out
pretty clearly. Yes, there are "hybrids" that sort of bridge the gap -
but MOST of them are identified as such.
Most definirely not. There is a small percentage of metal even in
organic pads, and the metal does not need to be iron. And "ceramic"
has nothing to do with "dust".
A ceramic is a vitified clay base which may or may not have metals
also included. A ceramic does not use phenol;ic binders.
Again - READ the stuff I posted for you.
On Mon, 15 Jan 2018 07:54:12 -0800 (PST),
Terry Schwartz wrote:
I get your point, even ensconced inside the sarcasm, so I'll just say it
bluntly that I do realize 99.99% of the people out there do not care that
they're completely unable to intelligently purchase things using a modicum
These people all want a "number line" decision, where they can use the
good, better, best by "marketing derived" criteria, such as silly words
like "ceramic" (where one spec of clay makes it a ceramic) and
"semi-metallic" (where one spec of iron makes it metallic).
You're one of those people, most likely (based on Occam's Razor deduction),
and that's fine.
You *think* you're intelligently choosing a brake pad, and that's fine too.
You may even buy by one of the three marketing-induced criteria:
a. If you're cost conscious, you buy the cheapest FF that fits.
b. If you're value conscious, you buy the mid FFs (with a small price bump)
c. If you're status conscious, you buy the high FFs (bigger price jump)
I'm not like you.
I like to *understand* that which I buy.
That's my take on the main difference between you and me base on the one
line you wrote.
I like to make intelligent buying decisions.
You apparently don't care to - and that's fine.
On Tue, 16 Jan 2018 02:10:29 -0000 (UTC), Mad Roger
And YOU think YOU are smart. (nobody else does - sorry to break your
and if you are SMART you buy the type of pad that matches
yourdriving requirements - which for most commuters is a standard
organic pad, for heavy duty use, a semi metallioc, and for high speed
light duty, generally a ceramic.
And yet you most certainly do NOT when it comes to brakes. You are
totally clueless and uneducatable
On Sun, 14 Jan 2018 17:58:04 -0800 (PST),
That's why I say those who say "you get what you pay for" are misguided
because a $157 pad "might" be just as good or bad as a $20 pad, where I can
prove this statement for the $300 20W Panasonic speakers in a Toyota since
I know the specs on the $50 speakers at Crutchfields.
Even at Crutchfields, you can get a good $50 speaker or a less-good $50
speaker, and the price is exactly the same.
So if someone tells me "you get what you pay for", they'll get the same
rant from me that everyone loves to pick products off a number line, but
the real number line is a bunch of specs, and not a simple price.
That's retail for you! :)
I think price is not an indication of anything other than what the
marketing can make people pay. It's certainly not an indication of quality.
I'm not sure what you mean by "scrapyards". To me, that means a junk yard,
which contains dead cars. I wouldn't buy brakes off a dead car for a
billion reasons which are obvious so I shouldn't need to state it.
What's the difference between my concept of a junkyard (which contains
entire cars that were thrown away) and your scrapyard?
Are you talking about *used* brake pads or *new* brake pads?
There is no other logical conclusion to be made, given the information we
have. Price is NOT the determinant of a good or bad brake pad.
The sad thing is that there is no determinant we can make that will hold
true other than there is no difference practically that you can do anything
I'm NOT saying they are all the same. I'm saying we consumers can't tell by
having two of them in our hand or having two of them sold online.
On Mon, 15 Jan 2018 14:19:40 -0000 (UTC), Mad Roger
You still have not learned ANYTHING?????
The specs on speakers are known to be some of the best fiction ever
written, followed only by the specs on consumer stereo equipment.
You "only" get what you pay for - and then only if you are both lucky
and astute. You SELDOM get more than what you pay for
You can take THAT to the bank.
Because someone was unloading something they didn't need, at a price
to get it off their shelves - and your requirements were not severe
enough to require anything better.
I've also been "lucky" enough to pick up some real "bargoons" by
being at the right place at the right time. I often buy what no-one
wants any more - nobody inOntario wanted a 1972 Pontiac Firenza in
1974 or 1975 - so I gor an almost pristine Vauxhaul Viva HC Magnum
coupe for $75 - and it served me well for a number of years before I
sold it to a friend of my wife, who needed a car and had no money for
something "good" - and she drove it another 7 years untill it required
a part that was not readily available or available at a decent cost .
I got "more than my money's worth" - I got "more than I paid for".
The same with my current pickup truck which I bought for $1500 because
nobody wanted a meticulously maintained 16 year old ford Ranger with
over 300,000km on it. It's been virtually trouble free for 6 years -
I've spent about $1500 on repairs over more than 50,000km, and all
indications areI'll get a few more years out of it. I got more than
my money's worth.
In both cases It was because I new the "value" of what I was buying
better than both the seller and other potential buyers.
You are FAR more likely to get less than you paid for - particularly
when buying any commodity new at retail - where you are SIGNIFICANTLY
less likely to get more than you pay for.
Price is not an accurate predictor of quality, but with a few other
often obvious clues, it is a pretty reliable indicator.
It is, as I have stated, an indicator, but not a predictor or
guarantee of quality.
No they are not - and in MANY places it is illegal to sell used brake
parts and used exhaust/emission parts.
Sometimes a car ends up in a scrapyard with lots of brand new parts
on it. The owner puts $3000 into making it safe to drive - new brakes,
suspension,and tires - the either has it hit, or blows a motor or
transmission, and decides not to keep it and repair it - or they spend
all kinds of money fixing it up - making it into their ":boy racer's
wet dream" and then cannot get it to pass smog - and it ends up in the
scrapyard with LOTS of good and/or expensive parts on it.
That said - as a matter of principal - unless no other adequate
source of brake parts was available, I'd be looking elsewhere - first.
Have I used "used" brake parts in the past??
Yes. I put a complete used rear axle from a '63 Belvedere into my '53
Coronet - brakes and all - as an upgrade when the originals failed and
OEM parts were not readilly available, and the old design was less
ANd I put used parts on my '49 VW in Livingstone Zambia. Where was I
going to get new parts??????? On a Sunday afternoon half way between
Choima and Macha - (look it up on Google Earth - and keep in mind
this was 44 years ago - - - - .
Perhaps not of a good one, but quite often of an inferior one
again, bushels of bovine excrement.
And why do you, like so many "millenials" (I'm aking an assumption
here from significant evidence) INSIST on buying everything
Obviously not sufficientfor a 3 ton vehicle going 100MPH - and
definitely not as good after a long downhill stop - -- but likely, at
low speeds - al ot better than you suspect!!!
There is SIGNIFICANT difference between different compounds of
"rubber" pads for rim brakes - includingin their stopping power and
their destructive effect on rims - some better for chromed rims, and
others for Alloy rims - some working better for side-pull, and others
for center pull (different amounts of pressure available)
More of "all you ever wanted to know about friction materials" but
were afraid to ask - - -
a whole lot more!!!!!!!!!!!
On Tue, 16 Jan 2018 08:45:56 -0800 (PST),
Yup. Basic Economics 101. Price is only a function of demand.
Price is never directly related to quality.
Price is only a function of demand.
Demand is a function of lots of complex variables, which is why they
invented Marketing (to greatly influence the demand).
I can't imagine buying used brake shoes or pads off a scrapped car.
I just can't.
Whoever proposes to buy brake pads and shoes off of junked cars is fine
with his logic, but he doesn't need to repeat it since it's not something
most of us would do.
I can see buying some parts at a scrap yard (e.g., a door or a fender), but
I just can't see buying a brake pad or shoe off a scrapped car.
How do you even do that? Do you walk around the junk yard to look for your
exact year, make and model and then pull the wheels and then pull the pads?
That's a lot of work, if you even find the right make and model, and then
if you can get to it (since they pile these things five cars high
sometimes) and if you can get the rusted lug bolts and brake drums off and
then you have to disassemble the brakes.
Seems like a *lot* of work for a brake shoe that will be "iffy" because you
have no way of knowing their condition ahead of time.
Or, maybe the junk yard does that for you, but then you are just staring at
a pile of brake shoes on the wall, which maybe, if you're lucky, have
accurate designations for the make and model of the vehicle they came off
I guess if you bring your old shoes with you, you can match them, but that
means your car is on blocks the whole time you do this, so you have to have
a second vehicle to do it.
I just don't see *how* it's practicable.
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