Honda Car Forum

"jim beam" <spamvortex@bad.example.net> wrote in message
news:qLWdnQoKN6A3Wc3bnZ2dnUVZ_hudnZ2d@speakeasy.ne t...
> Michael Pardee wrote:
>> "jim beam" <spamvortex@bad.example.net> wrote in message
>> news:27ydneh3Kqnl_s3bnZ2dnUVZ_jWdnZ2d@speakeasy.ne t...
>>> Michael Pardee wrote:
>>>> I'm convinced front drums are what gave drum brakes their reputation as
>>>> second rate.
>>> i'd say it differently - it's front drums that /prove/ they're second
>>> rate! their action is non-linear and they can only dump heat /through/
>>> the drum metal by conduction, not direct to atmosphere like a disk.
>>>
>>
>> They are definitely second rate for the front, where they have lots of
>> heat to dump. Drum brakes fade like crazy in that application. That isn't
>> an issue in the rear.
>>
>> From Edmunds techcenter @ http://tinyurl.com/6r6kh : ".. the truth is
>> that today's disc/drum setups are completely adequate for the majority of
>> new cars. Remember that both disc and drum brake design has been vastly
>> improved in the last 20 years. In fact, the current rear drum brake
>> systems on today's cars would provide better stopping performance then
>> [sic] the front disc setups of the '70s.
>
> eh? that's bullshit. whoever wrote that is basing it on the erroneous
> supposition that because drum brakes are still used, there must be a
> reason, and is just guessing that it's about performance. but it's just a
> guess and has no basis in fact if they'd bothered to look up performance
> figures. the reason drum brakes are used is cost and hand brake
> implementation. and market segmentation creeps in there too to some
> extent.
>
>> And today's front disc brakes are truly exceptional in terms of stopping
>> power. Combined with the fact that between 60 and 90 percent of a
>> vehicle's stopping power comes from the front wheels, it's clear that a
>> well-designed, modern drum brake is all that's required for most rear
>> wheel brake duty."
>
> what's required and what's best are not the same thing.
>

The part before the excerpt notes that drums are used because they are less
expensive. Their point is that drums are adequate for the application. Maybe
not "best" but "good enough."

Mike

"Matt Ion" <soundy106@gmail.com> wrote in message
news:IL24i.201980$aG1.43585@pd7urf3no...

> You'll note that drums are still used almost universally in semi-trailer
> rigs, where massive stopping power is of utmost importance.
>
> Of course, if you really want to confuse the issue, you can always look at
> the "hub brakes" used on train cars....
>

In trucks and trains the brakes are pre-engaged; air pressure is required to
release them. It is easier to do that with drums than disks.

Mike

Dave Kelsen wrote:
> On 5/20/2007 4:59 PM jim beam spake these words of knowledge:
>
>> Michael Pardee wrote:
>>> "jim beam" <spamvortex@bad.example.net> wrote in message
>>> news:27ydneh3Kqnl_s3bnZ2dnUVZ_jWdnZ2d@speakeasy.ne t...
>>>> Michael Pardee wrote:
>>>>> I'm convinced front drums are what gave drum brakes their
>>>>> reputation as second rate.
>>>> i'd say it differently - it's front drums that /prove/ they're
>>>> second rate! their action is non-linear and they can only dump heat
>>>> /through/ the drum metal by conduction, not direct to atmosphere
>>>> like a disk.
>>>>
>>>
>>> They are definitely second rate for the front, where they have lots
>>> of heat to dump. Drum brakes fade like crazy in that application.
>>> That isn't an issue in the rear.
>>>
>>> From Edmunds techcenter @ http://tinyurl.com/6r6kh : ".. the truth is
>>> that today's disc/drum setups are completely adequate for the
>>> majority of new cars. Remember that both disc and drum brake design
>>> has been vastly improved in the last 20 years. In fact, the current
>>> rear drum brake systems on today's cars would provide better stopping
>>> performance then [sic] the front disc setups of the '70s.
>>
>> eh? that's bullshit. whoever wrote that is basing it on the
>> erroneous supposition that because drum brakes are still used, there
>> must be a reason, and is just guessing that it's about performance.
>> but it's just a guess and has no basis in fact if they'd bothered to
>> look up performance figures. the reason drum brakes are used is cost
>> and hand brake implementation. and market segmentation creeps in
>> there too to some extent.
>
> Christ, Jim; is there any ****ing way you could be more pompous? Man!
>
> For what it's worth, you might try actually reading the paragraph above
> yours. Nothing is said about the reason drum brakes are used. Only
> that they are better than they used to be, and in the following
> paragraph, that they are adequate to the job requirements.
>
> Through the years you've shown yourself to be very knowledgeable, as
> well as high-handed, overbearing, impatient and rude.
>
> Or maybe it's just me. Ah, well, it's usenet.
>
"the current rear drum brake systems on today's cars would provide
better stopping performance then [sic] the front disc setups of the
'70s." is bullshit. it has no basis in fact - it's simply supposition
for the reasons i outlined before.

Michael Pardee wrote:
> "Matt Ion" <soundy106@gmail.com> wrote in message
> news:IL24i.201980$aG1.43585@pd7urf3no...
>
>> You'll note that drums are still used almost universally in semi-trailer
>> rigs, where massive stopping power is of utmost importance.
>>
>> Of course, if you really want to confuse the issue, you can always look at
>> the "hub brakes" used on train cars....
>>
>
> In trucks and trains the brakes are pre-engaged; air pressure is required to
> release them. It is easier to do that with drums than disks.
>
true!

On 5/20/2007 8:54 PM jim beam spake these words of knowledge:

> Dave Kelsen wrote:
>> On 5/20/2007 4:59 PM jim beam spake these words of knowledge:
>>
>>> Michael Pardee wrote:
>>>> "jim beam" <spamvortex@bad.example.net> wrote in message
>>>> news:27ydneh3Kqnl_s3bnZ2dnUVZ_jWdnZ2d@speakeasy.ne t...
>>>>> Michael Pardee wrote:
>>>>>> I'm convinced front drums are what gave drum brakes their
>>>>>> reputation as second rate.
>>>>> i'd say it differently - it's front drums that /prove/ they're
>>>>> second rate! their action is non-linear and they can only dump heat
>>>>> /through/ the drum metal by conduction, not direct to atmosphere
>>>>> like a disk.
>>>>>
>>>>
>>>> They are definitely second rate for the front, where they have lots
>>>> of heat to dump. Drum brakes fade like crazy in that application.
>>>> That isn't an issue in the rear.
>>>>
>>>> From Edmunds techcenter @ http://tinyurl.com/6r6kh : ".. the truth is
>>>> that today's disc/drum setups are completely adequate for the
>>>> majority of new cars. Remember that both disc and drum brake design
>>>> has been vastly improved in the last 20 years. In fact, the current
>>>> rear drum brake systems on today's cars would provide better stopping
>>>> performance then [sic] the front disc setups of the '70s.
>>>
>>> eh? that's bullshit. whoever wrote that is basing it on the
>>> erroneous supposition that because drum brakes are still used, there
>>> must be a reason, and is just guessing that it's about performance.
>>> but it's just a guess and has no basis in fact if they'd bothered to
>>> look up performance figures. the reason drum brakes are used is cost
>>> and hand brake implementation. and market segmentation creeps in
>>> there too to some extent.
>>
>> Christ, Jim; is there any ****ing way you could be more pompous? Man!
>>
>> For what it's worth, you might try actually reading the paragraph above
>> yours. Nothing is said about the reason drum brakes are used. Only
>> that they are better than they used to be, and in the following
>> paragraph, that they are adequate to the job requirements.
>>
>> Through the years you've shown yourself to be very knowledgeable, as
>> well as high-handed, overbearing, impatient and rude.
>>
>> Or maybe it's just me. Ah, well, it's usenet.
>>
> "the current rear drum brake systems on today's cars would provide
> better stopping performance then [sic] the front disc setups of the
> '70s." is bullshit. it has no basis in fact - it's simply supposition
> for the reasons i outlined before.

Thank you for your reasonable response to my outburst.

I would think that to test that claim, you'd have to find figures on
vehicles from the 70's which had disc front brakes - not difficult - and
current vehicles which have drum front brakes, as well as similar weight
and tire characteristics to those 70's cars, which I imagine would be
awfully difficult. Maybe tractor-trailer rigs?


RFT!!!
Dave Kelsen
--
"SATAN, SATAN! It's the main megafurnace! She's losin' power and the
temperature is dropping fast! I'm not sure if I can hold her!" --
Scotty in Hell

Dave Kelsen wrote:
> On 5/20/2007 8:54 PM jim beam spake these words of knowledge:
>
>> Dave Kelsen wrote:
>>> On 5/20/2007 4:59 PM jim beam spake these words of knowledge:
>>>
>>>> Michael Pardee wrote:
>>>>> "jim beam" <spamvortex@bad.example.net> wrote in message
>>>>> news:27ydneh3Kqnl_s3bnZ2dnUVZ_jWdnZ2d@speakeasy.ne t...
>>>>>> Michael Pardee wrote:
>>>>>>> I'm convinced front drums are what gave drum brakes their
>>>>>>> reputation as second rate.
>>>>>> i'd say it differently - it's front drums that /prove/ they're
>>>>>> second rate! their action is non-linear and they can only dump
>>>>>> heat /through/ the drum metal by conduction, not direct to
>>>>>> atmosphere like a disk.
>>>>>>
>>>>>
>>>>> They are definitely second rate for the front, where they have lots
>>>>> of heat to dump. Drum brakes fade like crazy in that application.
>>>>> That isn't an issue in the rear.
>>>>>
>>>>> From Edmunds techcenter @ http://tinyurl.com/6r6kh : ".. the truth
>>>>> is that today's disc/drum setups are completely adequate for the
>>>>> majority of new cars. Remember that both disc and drum brake design
>>>>> has been vastly improved in the last 20 years. In fact, the current
>>>>> rear drum brake systems on today's cars would provide better
>>>>> stopping performance then [sic] the front disc setups of the '70s.
>>>>
>>>> eh? that's bullshit. whoever wrote that is basing it on the
>>>> erroneous supposition that because drum brakes are still used, there
>>>> must be a reason, and is just guessing that it's about performance.
>>>> but it's just a guess and has no basis in fact if they'd bothered to
>>>> look up performance figures. the reason drum brakes are used is
>>>> cost and hand brake implementation. and market segmentation creeps
>>>> in there too to some extent.
>>>
>>> Christ, Jim; is there any ****ing way you could be more pompous? Man!
>>>
>>> For what it's worth, you might try actually reading the paragraph
>>> above yours. Nothing is said about the reason drum brakes are used.
>>> Only that they are better than they used to be, and in the following
>>> paragraph, that they are adequate to the job requirements.
>>>
>>> Through the years you've shown yourself to be very knowledgeable, as
>>> well as high-handed, overbearing, impatient and rude.
>>>
>>> Or maybe it's just me. Ah, well, it's usenet.
>>>
>> "the current rear drum brake systems on today's cars would provide
>> better stopping performance then [sic] the front disc setups of the
>> '70s." is bullshit. it has no basis in fact - it's simply supposition
>> for the reasons i outlined before.
>
> Thank you for your reasonable response to my outburst.
>
> I would think that to test that claim, you'd have to find figures on
> vehicles from the 70's which had disc front brakes - not difficult - and
> current vehicles which have drum front brakes, as well as similar weight
> and tire characteristics to those 70's cars, which I imagine would be
> awfully difficult. Maybe tractor-trailer rigs?

no, the baseless bull is that current /rear/ brakes are more effective
than disks of the 70's. and for testing, you want to eliminate
variables, especially tires.

On 5/21/2007 7:50 AM jim beam spake these words of knowledge:

> Dave Kelsen wrote:
>> On 5/20/2007 8:54 PM jim beam spake these words of knowledge:
>>
>>> Dave Kelsen wrote:
>>>> On 5/20/2007 4:59 PM jim beam spake these words of knowledge:
>>>>
>>>>> Michael Pardee wrote:
>>>>>> "jim beam" <spamvortex@bad.example.net> wrote in message
>>>>>> news:27ydneh3Kqnl_s3bnZ2dnUVZ_jWdnZ2d@speakeasy.ne t...
>>>>>>> Michael Pardee wrote:
>>>>>>>> I'm convinced front drums are what gave drum brakes their
>>>>>>>> reputation as second rate.
>>>>>>> i'd say it differently - it's front drums that /prove/ they're
>>>>>>> second rate! their action is non-linear and they can only dump
>>>>>>> heat /through/ the drum metal by conduction, not direct to
>>>>>>> atmosphere like a disk.
>>>>>>>
>>>>>>
>>>>>> They are definitely second rate for the front, where they have lots
>>>>>> of heat to dump. Drum brakes fade like crazy in that application.
>>>>>> That isn't an issue in the rear.
>>>>>>
>>>>>> From Edmunds techcenter @ http://tinyurl.com/6r6kh : ".. the truth
>>>>>> is that today's disc/drum setups are completely adequate for the
>>>>>> majority of new cars. Remember that both disc and drum brake design
>>>>>> has been vastly improved in the last 20 years. In fact, the current
>>>>>> rear drum brake systems on today's cars would provide better
>>>>>> stopping performance then [sic] the front disc setups of the '70s.
>>>>>
>>>>> eh? that's bullshit. whoever wrote that is basing it on the
>>>>> erroneous supposition that because drum brakes are still used, there
>>>>> must be a reason, and is just guessing that it's about performance.
>>>>> but it's just a guess and has no basis in fact if they'd bothered to
>>>>> look up performance figures. the reason drum brakes are used is
>>>>> cost and hand brake implementation. and market segmentation creeps
>>>>> in there too to some extent.
>>>>
>>>> Christ, Jim; is there any ****ing way you could be more pompous? Man!
>>>>
>>>> For what it's worth, you might try actually reading the paragraph
>>>> above yours. Nothing is said about the reason drum brakes are used.
>>>> Only that they are better than they used to be, and in the following
>>>> paragraph, that they are adequate to the job requirements.
>>>>
>>>> Through the years you've shown yourself to be very knowledgeable, as
>>>> well as high-handed, overbearing, impatient and rude.
>>>>
>>>> Or maybe it's just me. Ah, well, it's usenet.
>>>>
>>> "the current rear drum brake systems on today's cars would provide
>>> better stopping performance then [sic] the front disc setups of the
>>> '70s." is bullshit. it has no basis in fact - it's simply supposition
>>> for the reasons i outlined before.
>>
>> Thank you for your reasonable response to my outburst.
>>
>> I would think that to test that claim, you'd have to find figures on
>> vehicles from the 70's which had disc front brakes - not difficult - and
>> current vehicles which have drum front brakes, as well as similar weight
>> and tire characteristics to those 70's cars, which I imagine would be
>> awfully difficult. Maybe tractor-trailer rigs?
>
> no, the baseless bull is that current /rear/ brakes are more effective
> than disks of the 70's. and for testing, you want to eliminate
> variables, especially tires.

That's what I was saying; you'd have to have vehicles with similar
weight and tire characteristics in order to minimize those differences
as factors.

RFT!!!
Dave Kelsen
--
My dumb brother says life is all about compassion, wisdom and love for
our fellow man. What an idiot! Life is about peace and understanding
and building a world full of friendship for all mankind. Dumbass.

jim beam <spamvortex@bad.example.net> wrote in
news:27ydneh3Kqnl_s3bnZ2dnUVZ_jWdnZ2d@speakeasy.ne t:


>
> a number of manufacturers don't have slide pins on rear disks - they
> use old fashioned twin-piston calipers because there are no steering
> geometry constraints. [single piston front calipers were originally
> born of the desire to create negative steering scrub radius.]



No. Single-piston brakes are CHEAPER. Way, WAY cheaper. Single piston
brakes were adopted for economy reasons and for no other.


--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

Tegger wrote:
> jim beam <spamvortex@bad.example.net> wrote in
> news:27ydneh3Kqnl_s3bnZ2dnUVZ_jWdnZ2d@speakeasy.ne t:
>
>
>> a number of manufacturers don't have slide pins on rear disks - they
>> use old fashioned twin-piston calipers because there are no steering
>> geometry constraints. [single piston front calipers were originally
>> born of the desire to create negative steering scrub radius.]
>
>
>
> No. Single-piston brakes are CHEAPER. Way, WAY cheaper. Single piston
> brakes were adopted for economy reasons and for no other.
>
>
not that simple.

regarding the single/double thing, there's a few factors at play, one
being that the caliper casting for single piston needs better q.c. to
take the fatigue load of spanning the disk in a single piece and the
more complex shape. with twin piston, there are two halves that bolt
together and q.c. on a single more compact part is easier to cast. the
extra piston is more expensive, but the housing can be cheaper and
machining access is easier.

but the biggest factor is steering geometry. by far. that's why you
have "double piston" calipers like this:
http://www2.partstrain.com/products/....html?index=17
to get negative scrub radius, you have to get the hub face as close to
the bottom swivel as possible. you can do that easily with single
piston [single sided] caliper, but not easily with double [sided] unless
you have shallow pistons and thin pads. that's not acceptable for
production cars.