Comparison of Auminium, Steel and Carbon forks?

[Tom Sherman]

The "jim beam" sock puppet wrote:
> Tom Sherman wrote:
>> "jim beam" wrote:
>>> [...]
>>> well, krygowski picks up a check for being an "engineering" professor,
>>> but he doesn't know his ass from his elbow, and jobst brandt, esteemed
>>> stanford alumni, doesn't know a damned thing about fatigue, deformation
>>> or strength of materials. your conspicuous absence from all /those/
>>> debates doesn't show me you have credentials.[...]
>>>
>> Gee "jim", ever consider the possiblity that "Mike" is a newcomer to
>> the group? That would explain his lack or participation in previous
>> debates, no?
>>
>
> gee tom, don't you think that pulling the "30 year veteran" card carries
> some responsibility to do some homework?
>
Researching archived RBT posts? Certainly not, since discussions can
stand on their own, regardless of past history of the posters, no?

After all "jim", that is YOUR argument of why a sock puppet is no less
credible than someone using their real name.

> goddamned lightweight.

Ooooh, an insult from a sock puppet!

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

 

[Mike]

In article <[email protected]>, [email protected] says...
> Mike wrote:
> > In article <[email protected]>, [email protected] says...
> > You may re-parrot "hysteresis in polymers" but without evidence that this provides a measurable reduction in the
> > transfer of vibrational energy _taking into account the differing geometry, mass and design of forks built from
> > differing materials_ you have not proved your case. If you _can_ supply such evidence, I will be willing to admit to
> > the accuracy of your hypothesis.
>
> you've still gotten your approach inverted. as stated before, the
> behavior of polymers are a given. even you admit it. now what /you/
> have to do is argue the extent to which cf reinforcement mitigates that.
> your "30 year career in materials physics" should make it easy, yes?
>
Yet still it goes on, and on.., and on...

Indisputible factoid: Polymers exhibit hysteresis upon deformation.

Ridiculous conclusion: Therefore they absorb all possible vibrational frequencies. Completely. Absolutely. No need
to demonstrate this - it is a given, a fact, an act of God. You can ride across a rough chip surface and won't feel a
thing as long as your front fork is cf. Heck - you can ride down a staircase on a 700-21C tyre at 125 PSI and won't
feel a thing as long as your front fork is cf.

Now read the following - carefully - please. I haver itemised things to make it easier for your comprehension.

1) I have made _no_ claims as to the benefits of cf over aluminium or steel. I have made no claims as to the benefit
of steel over cf or aluminium. I have made no claims as to the benefits of aluminium over steel or cf. But you have.

2) I have suggested that experimental evidence (do you need to read that again? e-x-p-e-r-i-m-e-n-t-a-l e-v-i-d-e-n-
c-e) would be required to convince me that any of cf, aluminium or steel, has a significant (or even measurable)
benefit over the other materials for vibration-mitigation in forks. You haven't supplied it.

3) It is you who has made the claims - it is you who needs to provide the evidence. Mention of the hysteretic
properties of polymers is not evidence, specifically because the discussion is not about the capacity for vibratiuonal
absorption of materials, but instead is about the capacity for vibrational aborption of _structures_ (i.e. forks). You
need to demonstrate that such a capacity in the material confers a measurable advantage in the structure. Oterwise,
your claim is not dissimilar to claiming that (for example), because steel exhibits greater tensile strength than nylon
(as a function of cross-sectional area), _any_ steel rope must be stronger than _any_ nylon rope. That arguement is
patently absurd, and so is yours unless you take into account the structure of forks, as well as the materials from
which they are constructed. You need to supply the evidence, because it is you who makes the claims.

4) I don't expect a sensible answer - you appear incapable of providing them. Why not try and surprise me?

Mike

 

[Mike]

In article <[email protected]>, [email protected] says...
> Tom Sherman wrote:
> > "jim beam" wrote:
> >> [...]
> >> well, krygowski picks up a check for being an "engineering" professor,
> >> but he doesn't know his ass from his elbow, and jobst brandt, esteemed
> >> stanford alumni, doesn't know a damned thing about fatigue, deformation
> >> or strength of materials. your conspicuous absence from all /those/
> >> debates doesn't show me you have credentials.[...]
> >>

Whereas, your presence in numerous debates makes it clear to me that your purported "expertise" in one small field,
does not aid you at all in coming to sensible conclusions in applications even marginally outside your field of
ewxperience.

> > Gee "jim", ever consider the possiblity that "Mike" is a newcomer to the
> > group? That would explain his lack or participation in previous debates,
> > no?
> >
>
> gee tom, don't you think that pulling the "30 year veteran" card carries
> some responsibility to do some homework?
>
You want me to lie about my age, Jim?

 

[jim beam]

Mike wrote:
> In article <[email protected]>, [email protected] says...
>> Tom Sherman wrote:
>>> "jim beam" wrote:
>>>> [...]
>>>> well, krygowski picks up a check for being an "engineering" professor,
>>>> but he doesn't know his ass from his elbow, and jobst brandt, esteemed
>>>> stanford alumni, doesn't know a damned thing about fatigue, deformation
>>>> or strength of materials. your conspicuous absence from all /those/
>>>> debates doesn't show me you have credentials.[...]
>>>>
>
> Whereas, your presence in numerous debates makes it clear to me that your purported "expertise" in one small field,
> does not aid you at all in coming to sensible conclusions in applications even marginally outside your field of
> ewxperience.
>
>>> Gee "jim", ever consider the possiblity that "Mike" is a newcomer to the
>>> group? That would explain his lack or participation in previous debates,
>>> no?
>>>
>> gee tom, don't you think that pulling the "30 year veteran" card carries
>> some responsibility to do some homework?
>>
> You want me to lie about my age, Jim?

no, but i'd sure love to know how a "30-year veteran in materials
physics" can get bamboozled by b.s. he reads on newsgroups and
apparently doesn't have any interest in materials theory.

 

[jim beam]

Mike wrote:
> In article <[email protected]>, [email protected] says...
>> Mike wrote:
>>> In article <[email protected]>, [email protected] says...
>>> You may re-parrot "hysteresis in polymers" but without evidence that this provides a measurable reduction in the
>>> transfer of vibrational energy _taking into account the differing geometry, mass and design of forks built from
>>> differing materials_ you have not proved your case. If you _can_ supply such evidence, I will be willing to admit to
>>> the accuracy of your hypothesis.
>> you've still gotten your approach inverted. as stated before, the
>> behavior of polymers are a given. even you admit it. now what /you/
>> have to do is argue the extent to which cf reinforcement mitigates that.
>> your "30 year career in materials physics" should make it easy, yes?
>>
> Yet still it goes on, and on.., and on...
>
> Indisputible factoid: Polymers exhibit hysteresis upon deformation.
>
> Ridiculous conclusion: Therefore they absorb all possible vibrational frequencies. Completely. Absolutely. No need
> to demonstrate this - it is a given, a fact, an act of God. You can ride across a rough chip surface and won't feel a
> thing as long as your front fork is cf. Heck - you can ride down a staircase on a 700-21C tyre at 125 PSI and won't
> feel a thing as long as your front fork is cf.

hmmm, the ridiculous b.s. argument that contains nuggets of truth, only
to condemn with outrageous lies.


>
> Now read the following - carefully - please. I haver itemised things to make it easier for your comprehension.
>
> 1) I have made _no_ claims as to the benefits of cf over aluminium or steel. I have made no claims as to the benefit
> of steel over cf or aluminium. I have made no claims as to the benefits of aluminium over steel or cf. But you have.
>
> 2) I have suggested that experimental evidence (do you need to read that again? e-x-p-e-r-i-m-e-n-t-a-l e-v-i-d-e-n-
> c-e) would be required to convince me that any of cf, aluminium or steel, has a significant (or even measurable)
> benefit over the other materials for vibration-mitigation in forks. You haven't supplied it.

dude, you're the materials physicist!!! there's plenty of stuff on the
web, but /you/ can go ahead and cite the real deal!!!


>
> 3) It is you who has made the claims - it is you who needs to provide the evidence. Mention of the hysteretic
> properties of polymers is not evidence, specifically because the discussion is not about the capacity for vibratiuonal
> absorption of materials, but instead is about the capacity for vibrational aborption of _structures_ (i.e. forks). You
> need to demonstrate that such a capacity in the material confers a measurable advantage in the structure. Oterwise,
> your claim is not dissimilar to claiming that (for example), because steel exhibits greater tensile strength than nylon
> (as a function of cross-sectional area), _any_ steel rope must be stronger than _any_ nylon rope. That arguement is
> patently absurd, and so is yours unless you take into account the structure of forks, as well as the materials from
> which they are constructed. You need to supply the evidence, because it is you who makes the claims.

that is totally logically flawed. material properties of polymers are
indisputable - a subject you carefully avoid directly addressing,
although you're happy to put in a sentence with ridiculous garbage - and
yet you use the garbage part of the argument to extrapolate that it is
/all/ wrong.


>
> 4) I don't expect a sensible answer - you appear incapable of providing them. Why not try and surprise me?

why? you claim to be an expert, then you show yourself to be anything
but serious.

but who cares. the fact is, the fibers in composites like this transfer
load among themselves via their polymer matrix. since that polymer has
hysteresis, i.e. that load transfer is time dependent, load transmission
is not is not "pure" but colored by that polymer's ability to transmit.
this effect is affected by fiber density, layup, matrix polymer,
etc, but the "physics" are pretty basic. definitely something a
"30-year veteran" should understand.

[non-bike b.s. poisoned] examples of this effect in a 30-second google
search:
http://www.patentstorm.us/patents/5482774-description.html
http://www.nikkiso.co.jp/e-c_seihin/fukugozai/index.html
http://composite.about.com/library/PR/2001/bltekes2.htm
http://www.macqc.com/apps_industrial.php

 

[Mike]

In article <[email protected]>, [email protected] says...
> Mike wrote:

> > 3) It is you who has made the claims - it is you who needs to provide the evidence. Mention of the hysteretic
> > properties of polymers is not evidence, specifically because the discussion is not about the capacity for vibratiuonal
> > absorption of materials, but instead is about the capacity for vibrational aborption of _structures_ (i.e. forks). You
> > need to demonstrate that such a capacity in the material confers a measurable advantage in the structure. Oterwise,
> > your claim is not dissimilar to claiming that (for example), because steel exhibits greater tensile strength than nylon
> > (as a function of cross-sectional area), _any_ steel rope must be stronger than _any_ nylon rope. That arguement is
> > patently absurd, and so is yours unless you take into account the structure of forks, as well as the materials from
> > which they are constructed. You need to supply the evidence, because it is you who makes the claims.
>
> that is totally logically flawed. material properties of polymers are
> indisputable - a subject you carefully avoid directly addressing,
> although you're happy to put in a sentence with ridiculous garbage - and
> yet you use the garbage part of the argument to extrapolate that it is
> /all/ wrong.
>
It is like talking to a 5 year old.

I do _not_ dispute the fact that polymers have material properties that provide them with a capacity to absorb and
dampen vibration. I know this - I agree with you - I have "directly addressed" this in several posts. For the sake of
sanity, let's assume it is a given. Got that?

I _do_ dispute your premise that, as a result of these material properties, any and all cf forks are of necessity,
measurably better than any and all aluminium or steel shocks at reducing the transfer of vibrational energy from the
bottom of the fork to its top.

Note specifically the terms: 'measurably better', 'transfer', and 'any and all'. If you have proof of your thesis, then
supply it. If you believe that your thesis has been mis-stated, then re-state it. If you cannot do either of the above,
then admit to your error.

Mike

 

[jim beam]

Mike wrote:
> In article <[email protected]>, [email protected] says...
>> Mike wrote:
>
>>> 3) It is you who has made the claims - it is you who needs to provide the evidence. Mention of the hysteretic
>>> properties of polymers is not evidence, specifically because the discussion is not about the capacity for vibratiuonal
>>> absorption of materials, but instead is about the capacity for vibrational aborption of _structures_ (i.e. forks). You
>>> need to demonstrate that such a capacity in the material confers a measurable advantage in the structure. Oterwise,
>>> your claim is not dissimilar to claiming that (for example), because steel exhibits greater tensile strength than nylon
>>> (as a function of cross-sectional area), _any_ steel rope must be stronger than _any_ nylon rope. That arguement is
>>> patently absurd, and so is yours unless you take into account the structure of forks, as well as the materials from
>>> which they are constructed. You need to supply the evidence, because it is you who makes the claims.
>> that is totally logically flawed. material properties of polymers are
>> indisputable - a subject you carefully avoid directly addressing,
>> although you're happy to put in a sentence with ridiculous garbage - and
>> yet you use the garbage part of the argument to extrapolate that it is
>> /all/ wrong.
>>
> It is like talking to a 5 year old.
>
> I do _not_ dispute the fact that polymers have material properties that provide them with a capacity to absorb and
> dampen vibration. I know this - I agree with you - I have "directly addressed" this in several posts. For the sake of
> sanity, let's assume it is a given. Got that?

no, all you do is bleat about cites, complaining that, somehow absent
this information, it doesn't happen.


>
> I _do_ dispute your premise that, as a result of these material properties, any and all cf forks are of necessity,

i've never said that. don't put false words in my mouth.


> measurably better than any and all aluminium or steel shocks at reducing the transfer of vibrational energy from the
> bottom of the fork to its top.

see above.


>
> Note specifically the terms: 'measurably better', 'transfer', and 'any and all'. If you have proof of your thesis, then
> supply it. If you believe that your thesis has been mis-stated, then re-state it. If you cannot do either of the above,
> then admit to your error.

see above. and respond to what i first said. it happens for the
reasons stated. /you/, as the one disagreeing, and the one playing the
"30-year veteran" card have yet to say a damned thing other than an
appeal to faith.

 

[jim beam]

jim beam wrote:
> Mike wrote:
>> In article <[email protected]>,
>> [email protected] says...
>>> Mike wrote:
>>
>>>> 3) It is you who has made the claims - it is you who needs to
>>>> provide the evidence. Mention of the hysteretic properties of
>>>> polymers is not evidence, specifically because the discussion is not
>>>> about the capacity for vibratiuonal absorption of materials, but
>>>> instead is about the capacity for vibrational aborption of
>>>> _structures_ (i.e. forks). You need to demonstrate that such a
>>>> capacity in the material confers a measurable advantage in the
>>>> structure. Oterwise, your claim is not dissimilar to claiming that
>>>> (for example), because steel exhibits greater tensile strength than
>>>> nylon (as a function of cross-sectional area), _any_ steel rope must
>>>> be stronger than _any_ nylon rope. That arguement is patently
>>>> absurd, and so is yours unless you take into account the structure
>>>> of forks, as well as the materials from which they are constructed.
>>>> You need to supply the evidence, because it is you who makes the
>>>> claims.
>>> that is totally logically flawed. material properties of polymers
>>> are indisputable - a subject you carefully avoid directly addressing,
>>> although you're happy to put in a sentence with ridiculous garbage -
>>> and yet you use the garbage part of the argument to extrapolate that
>>> it is /all/ wrong.
>>>
>> It is like talking to a 5 year old.
>> I do _not_ dispute the fact that polymers have material properties
>> that provide them with a capacity to absorb and dampen vibration. I
>> know this - I agree with you - I have "directly addressed" this in
>> several posts. For the sake of sanity, let's assume it is a given. Got
>> that?
>
> no, all you do is bleat about cites, complaining that, somehow absent
> this information, it doesn't happen

omission: "with composites".

..
>
>
>>
>> I _do_ dispute your premise that, as a result of these material
>> properties, any and all cf forks are of necessity,
>
> i've never said that. don't put false words in my mouth.
>
>
>> measurably better than any and all aluminium or steel shocks at
>> reducing the transfer of vibrational energy from the bottom of the
>> fork to its top.
>
> see above.
>
>
>>
>> Note specifically the terms: 'measurably better', 'transfer', and 'any
>> and all'. If you have proof of your thesis, then supply it. If you
>> believe that your thesis has been mis-stated, then re-state it. If you
>> cannot do either of the above, then admit to your error.
>
> see above. and respond to what i first said. it happens for the
> reasons stated. /you/, as the one disagreeing, and the one playing the
> "30-year veteran" card have yet to say a damned thing other than an
> appeal to faith.