Re: [OT] car brakes

Robert Lorenzini

On Sat, 03 May 2008 21:06:41 GMT, Peter Cole <peter_cole@verizon.net> wrote:
>
> Cross-drilled seems to be more about looks than anything else. "Vented"
> or "ventilated" rotors are another matter. They appear to be reasonably
> effective, but it's not a *huge* effect (+40%, rather than 100%).
>

Vented (cross-drilled or slotted) rotors came from racing brakes
which use pads that boil gasses under heat. This is most noticeable
when bedding green pads and they act just like a tire hydroplaning
until most of the volatiles have disapated.

Bob

JG

'fu' - art, skill, workmanship - from the Chinese gong(1)fu(1) meaning
art, skill, workmanship.

JG

Nate Nagel

Robert Lorenzini wrote:
> On Sat, 03 May 2008 21:06:41 GMT, Peter Cole <peter_cole@verizon.net> wrote:
>
>>Cross-drilled seems to be more about looks than anything else. "Vented"
>>or "ventilated" rotors are another matter. They appear to be reasonably
>>effective, but it's not a *huge* effect (+40%, rather than 100%).
>>
>
>
> Vented (cross-drilled or slotted) rotors came from racing brakes
> which use pads that boil gasses under heat. This is most noticeable
> when bedding green pads and they act just like a tire hydroplaning
> until most of the volatiles have disapated.
>
> Bob

Again, what is commonly known as "vented rotors" have nothing to do with
venting the gases from the pads, and unless they are *also* crossdrilled
and/or slotted will have perfectly flat braking surfaces. The venting
is cast into the rotor in the form of spaces between the two braking
surfaces for air to flow.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Ben C

On 2008-05-04, Robert Lorenzini <bob@newportharbornet.com> wrote:
> On Sat, 03 May 2008 21:06:41 GMT, Peter Cole <peter_cole@verizon.net> wrote:
>>
>> Cross-drilled seems to be more about looks than anything else. "Vented"
>> or "ventilated" rotors are another matter. They appear to be reasonably
>> effective, but it's not a *huge* effect (+40%, rather than 100%).
>>
>
> Vented (cross-drilled or slotted) rotors came from racing brakes
> which use pads that boil gasses under heat. This is most noticeable
> when bedding green pads and they act just like a tire hydroplaning
> until most of the volatiles have disapated.

Do you know what gasses these are and how or why they are produced?

Jobst reckons this theory is myth and lore, and it does sound pretty
unlikely, but perhaps if more of the details were explained it wouldn't
seem so implausible.

Robert Lorenzini

On Sun, 04 May 2008 12:51:13 -0400, Nate Nagel <njnagel@roosters.net> wrote:
> Robert Lorenzini wrote:
>> On Sat, 03 May 2008 21:06:41 GMT, Peter Cole <peter_cole@verizon.net> wrote:
>>
>>>Cross-drilled seems to be more about looks than anything else. "Vented"
>>>or "ventilated" rotors are another matter. They appear to be reasonably
>>>effective, but it's not a *huge* effect (+40%, rather than 100%).
>>>
>>
>>
>> Vented (cross-drilled or slotted) rotors came from racing brakes
>> which use pads that boil gasses under heat. This is most noticeable
>> when bedding green pads and they act just like a tire hydroplaning
>> until most of the volatiles have disapated.
>>
>> Bob
>
> Again, what is commonly known as "vented rotors" have nothing to do with
> venting the gases from the pads, and unless they are *also* crossdrilled
> and/or slotted will have perfectly flat braking surfaces. The venting
> is cast into the rotor in the form of spaces between the two braking
> surfaces for air to flow.
>

Correct, different animal entirely.

Bob

Kerry Montgomery

"Ben C" <spamspam@spam.eggs> wrote in message
news:slrng1rtll.5ks.spamspam@bobomb.marioworld...
> On 2008-05-04, Robert Lorenzini <bob@newportharbornet.com> wrote:
>> On Sat, 03 May 2008 21:06:41 GMT, Peter Cole <peter_cole@verizon.net>
>> wrote:
>>>
>>> Cross-drilled seems to be more about looks than anything else. "Vented"
>>> or "ventilated" rotors are another matter. They appear to be reasonably
>>> effective, but it's not a *huge* effect (+40%, rather than 100%).
>>>
>>
>> Vented (cross-drilled or slotted) rotors came from racing brakes
>> which use pads that boil gasses under heat. This is most noticeable
>> when bedding green pads and they act just like a tire hydroplaning
>> until most of the volatiles have disapated.
>
> Do you know what gasses these are and how or why they are produced?
>
> Jobst reckons this theory is myth and lore, and it does sound pretty
> unlikely, but perhaps if more of the details were explained it wouldn't
> seem so implausible.

Ben C,
Vented is not cross-drilled or slotted. Vented is:
http://images.outdoorinteractive.net/mgen/530211_oi.jpg
cross-drilled is:
http://www.camarotech.com/images/Br...rossDrilled.jpg
slotted is:
http://ecx.images-amazon.com/images...BLL._AA160_.jpg
Don't know about steel or iron brake disk rotors, but the carbon ones used
on F1 racing cars (with carbon pads) don't have cross-drilling or slotting,
but do have venting.
Kerry

Ben C

On 2008-05-04, Kerry Montgomery <kamontgo@teleport.com> wrote:
>
> "Ben C" <spamspam@spam.eggs> wrote in message
> news:slrng1rtll.5ks.spamspam@bobomb.marioworld...
>> On 2008-05-04, Robert Lorenzini <bob@newportharbornet.com> wrote:
>>> On Sat, 03 May 2008 21:06:41 GMT, Peter Cole <peter_cole@verizon.net>
>>> wrote:
>>>>
>>>> Cross-drilled seems to be more about looks than anything else. "Vented"
>>>> or "ventilated" rotors are another matter. They appear to be reasonably
>>>> effective, but it's not a *huge* effect (+40%, rather than 100%).
>>>>
>>>
>>> Vented (cross-drilled or slotted) rotors came from racing brakes
>>> which use pads that boil gasses under heat. This is most noticeable
>>> when bedding green pads and they act just like a tire hydroplaning
>>> until most of the volatiles have disapated.
>>
>> Do you know what gasses these are and how or why they are produced?
>>
>> Jobst reckons this theory is myth and lore, and it does sound pretty
>> unlikely, but perhaps if more of the details were explained it wouldn't
>> seem so implausible.
>
> Ben C,
> Vented is not cross-drilled or slotted. Vented is:
> http://images.outdoorinteractive.net/mgen/530211_oi.jpg
> cross-drilled is:
> http://www.camarotech.com/images/Br...rossDrilled.jpg
> slotted is:
> http://ecx.images-amazon.com/images...BLL._AA160_.jpg

Yes I did realize that but no harm in clarifying it. I heard the point
of the slotting is to break up glaze on the pads.

Tom Sherman

Kerry Montgomery wrote:
> "Ben C" <spamspam@spam.eggs> wrote in message
> news:slrng1rtll.5ks.spamspam@bobomb.marioworld...
>> On 2008-05-04, Robert Lorenzini <bob@newportharbornet.com> wrote:
>>> On Sat, 03 May 2008 21:06:41 GMT, Peter Cole <peter_cole@verizon.net>
>>> wrote:
>>>> Cross-drilled seems to be more about looks than anything else. "Vented"
>>>> or "ventilated" rotors are another matter. They appear to be reasonably
>>>> effective, but it's not a *huge* effect (+40%, rather than 100%).
>>>>
>>> Vented (cross-drilled or slotted) rotors came from racing brakes
>>> which use pads that boil gasses under heat. This is most noticeable
>>> when bedding green pads and they act just like a tire hydroplaning
>>> until most of the volatiles have disapated.
>> Do you know what gasses these are and how or why they are produced?
>>
>> Jobst reckons this theory is myth and lore, and it does sound pretty
>> unlikely, but perhaps if more of the details were explained it wouldn't
>> seem so implausible.
>
> Ben C,
> Vented is not cross-drilled or slotted. Vented is:
> http://images.outdoorinteractive.net/mgen/530211_oi.jpg
> cross-drilled is:
> http://www.camarotech.com/images/Br...rossDrilled.jpg
> slotted is:
> http://ecx.images-amazon.com/images...BLL._AA160_.jpg
> Don't know about steel or iron brake disk rotors, but the carbon ones used
> on F1 racing cars (with carbon pads) don't have cross-drilling or slotting,
> but do have venting.

What do you call this type of rotor:
<http://farm3.static.flickr.com/2249/2163925995_f7a5dd2a3b.jpg?v=0>?

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

Michael Press

In article <slrng1rnul.4ke.bob@localhost.localdomain>,
Robert Lorenzini <bob@newportharbornet.com> wrote:

> On Sat, 03 May 2008 21:06:41 GMT, Peter Cole <peter_cole@verizon.net> wrote:
> >
> > Cross-drilled seems to be more about looks than anything else. "Vented"
> > or "ventilated" rotors are another matter. They appear to be reasonably
> > effective, but it's not a *huge* effect (+40%, rather than 100%).
> >
>
> Vented (cross-drilled or slotted) rotors came from racing brakes
> which use pads that boil gasses under heat. This is most noticeable
> when bedding green pads and they act just like a tire hydroplaning
> until most of the volatiles have disapated.

What is the chemical composition of the boiling gasses?
Do the boiling gasses come from the pads?

--
Michael Press

A Muzi

>> Peter Cole <peter_cole@verizon.net> wrote:
>>> Cross-drilled seems to be more about looks than anything else. "Vented"
>>> or "ventilated" rotors are another matter. They appear to be reasonably
>>> effective, but it's not a *huge* effect (+40%, rather than 100%).

> Robert Lorenzini <bob@newportharbornet.com> wrote:
>> Vented (cross-drilled or slotted) rotors came from racing brakes
>> which use pads that boil gasses under heat. This is most noticeable
>> when bedding green pads and they act just like a tire hydroplaning
>> until most of the volatiles have disapated.

Michael Press wrote:
> What is the chemical composition of the boiling gasses?
> Do the boiling gasses come from the pads?

Counterintuitive, isn't it? This guy thinks it happens:
http://www.innerauto.com/Auto_Part/Brake_Disc/

I'm not convinced ('gas' goes in the little hole??) or that taking one's
foot off a brake can break it.

These guys just say 'ducted', which is what I thought this conversation
was about earlier:
http://www.lexus.com/models/IS/feat...isc_brakes.html

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
** Posted from http://www.teranews.com **

Ben C

On 2008-05-04, A Muzi <am@yellowjersey.org> wrote:
>>> Peter Cole <peter_cole@verizon.net> wrote:
>>>> Cross-drilled seems to be more about looks than anything else. "Vented"
>>>> or "ventilated" rotors are another matter. They appear to be reasonably
>>>> effective, but it's not a *huge* effect (+40%, rather than 100%).
>
>> Robert Lorenzini <bob@newportharbornet.com> wrote:
>>> Vented (cross-drilled or slotted) rotors came from racing brakes
>>> which use pads that boil gasses under heat. This is most noticeable
>>> when bedding green pads and they act just like a tire hydroplaning
>>> until most of the volatiles have disapated.
>
> Michael Press wrote:
>> What is the chemical composition of the boiling gasses?
>> Do the boiling gasses come from the pads?
>
> Counterintuitive, isn't it? This guy thinks it happens:
> http://www.innerauto.com/Auto_Part/Brake_Disc/
>
> I'm not convinced ('gas' goes in the little hole??) or that taking one's
> foot off a brake can break it.

If gas did come off the pad where it touched the disk then it would have
nowhere to go except to try and squeeze round the edge of the pad or
build up into a sort of bubble. Either way the gas pressure would try to
push pad and disk apart. The holes would prevent that happening.

So I can see how the holes would work if the gas is there.

And just because I don't know what gas would come off brake pads doesn't
mean no gas does. After all what I don't know about brake pads would
fill a book.

clare at snyder dot ontario dot canada

On Sun, 04 May 2008 14:23:21 -0500, Tom Sherman
<sunsetss0003@REMOVETHISyahoo.com> wrote:

>Kerry Montgomery wrote:
>> "Ben C" <spamspam@spam.eggs> wrote in message
>> news:slrng1rtll.5ks.spamspam@bobomb.marioworld...
>>> On 2008-05-04, Robert Lorenzini <bob@newportharbornet.com> wrote:
>>>> On Sat, 03 May 2008 21:06:41 GMT, Peter Cole <peter_cole@verizon.net>
>>>> wrote:
>>>>> Cross-drilled seems to be more about looks than anything else. "Vented"
>>>>> or "ventilated" rotors are another matter. They appear to be reasonably
>>>>> effective, but it's not a *huge* effect (+40%, rather than 100%).
>>>>>
>>>> Vented (cross-drilled or slotted) rotors came from racing brakes
>>>> which use pads that boil gasses under heat. This is most noticeable
>>>> when bedding green pads and they act just like a tire hydroplaning
>>>> until most of the volatiles have disapated.
>>> Do you know what gasses these are and how or why they are produced?
>>>
>>> Jobst reckons this theory is myth and lore, and it does sound pretty
>>> unlikely, but perhaps if more of the details were explained it wouldn't
>>> seem so implausible.
>>
>> Ben C,
>> Vented is not cross-drilled or slotted. Vented is:
>> http://images.outdoorinteractive.net/mgen/530211_oi.jpg
>> cross-drilled is:
>> http://www.camarotech.com/images/Br...rossDrilled.jpg
>> slotted is:
>> http://ecx.images-amazon.com/images...BLL._AA160_.jpg
>> Don't know about steel or iron brake disk rotors, but the carbon ones used
>> on F1 racing cars (with carbon pads) don't have cross-drilling or slotting,
>> but do have venting.
>
>What do you call this type of rotor:
><http://farm3.static.flickr.com/2249/2163925995_f7a5dd2a3b.jpg?v=0>?
Eyecandy.
** Posted from http://www.teranews.com **

Michael Press

In article <slrng1sie4.612.spamspam@bowser.marioworld>,
Ben C <spamspam@spam.eggs> wrote:

> On 2008-05-04, A Muzi <am@yellowjersey.org> wrote:
> >>> Peter Cole <peter_cole@verizon.net> wrote:
> >>>> Cross-drilled seems to be more about looks than anything else. "Vented"
> >>>> or "ventilated" rotors are another matter. They appear to be reasonably
> >>>> effective, but it's not a *huge* effect (+40%, rather than 100%).
> >
> >> Robert Lorenzini <bob@newportharbornet.com> wrote:
> >>> Vented (cross-drilled or slotted) rotors came from racing brakes
> >>> which use pads that boil gasses under heat. This is most noticeable
> >>> when bedding green pads and they act just like a tire hydroplaning
> >>> until most of the volatiles have disapated.
> >
> > Michael Press wrote:
> >> What is the chemical composition of the boiling gasses?
> >> Do the boiling gasses come from the pads?
> >
> > Counterintuitive, isn't it? This guy thinks it happens:
> > http://www.innerauto.com/Auto_Part/Brake_Disc/
> >
> > I'm not convinced ('gas' goes in the little hole??) or that taking one's
> > foot off a brake can break it.
>
> If gas did come off the pad where it touched the disk then it would have
> nowhere to go except to try and squeeze round the edge of the pad or
> build up into a sort of bubble. Either way the gas pressure would try to
> push pad and disk apart. The holes would prevent that happening.
>
> So I can see how the holes would work if the gas is there.
>
> And just because I don't know what gas would come off brake pads doesn't
> mean no gas does. After all what I don't know about brake pads would
> fill a book.

What gas evolves, what is its chemical composition,
and its partial pressure?

--
Michael Press

Kerry Montgomery

"Tom Sherman" <sunsetss0003@REMOVETHISyahoo.com> wrote in message
news:fvl2fc$3qa$1@registered.motzarella.org...
> Kerry Montgomery wrote:
>> "Ben C" <spamspam@spam.eggs> wrote in message
>> news:slrng1rtll.5ks.spamspam@bobomb.marioworld...
>>> On 2008-05-04, Robert Lorenzini <bob@newportharbornet.com> wrote:
>>>> On Sat, 03 May 2008 21:06:41 GMT, Peter Cole <peter_cole@verizon.net>
>>>> wrote:
>>>>> Cross-drilled seems to be more about looks than anything else.
>>>>> "Vented"
>>>>> or "ventilated" rotors are another matter. They appear to be
>>>>> reasonably
>>>>> effective, but it's not a *huge* effect (+40%, rather than 100%).
>>>>>
>>>> Vented (cross-drilled or slotted) rotors came from racing brakes
>>>> which use pads that boil gasses under heat. This is most noticeable
>>>> when bedding green pads and they act just like a tire hydroplaning
>>>> until most of the volatiles have disapated.
>>> Do you know what gasses these are and how or why they are produced?
>>>
>>> Jobst reckons this theory is myth and lore, and it does sound pretty
>>> unlikely, but perhaps if more of the details were explained it wouldn't
>>> seem so implausible.
>>
>> Ben C,
>> Vented is not cross-drilled or slotted. Vented is:
>> http://images.outdoorinteractive.net/mgen/530211_oi.jpg
>> cross-drilled is:
>> http://www.camarotech.com/images/Br...rossDrilled.jpg
>> slotted is:
>> http://ecx.images-amazon.com/images...BLL._AA160_.jpg
>> Don't know about steel or iron brake disk rotors, but the carbon ones
>> used on F1 racing cars (with carbon pads) don't have cross-drilling or
>> slotting, but do have venting.
>
> What do you call this type of rotor:
> <http://farm3.static.flickr.com/2249/2163925995_f7a5dd2a3b.jpg?v=0>?
>
> --
> Tom Sherman - Holstein-Friesland Bovinia
> The weather is here, wish you were beautiful


Tom,
I don't know - maybe high void-ratio rotationally slotted but transversely
compliant?
And, pretty as it is, it doesn't have the mathematical artistry of:
http://www.rider-inc.com/Ti_Rotor_P..._Rotor_Frnt.jpg
Kerry