Can improper use of back brakes cause the wheel rim to deform?

[Tim McNamara]

In article <[email protected]>,
jim beam <[email protected]> wrote:

> Tim McNamara wrote:
> > In article <[email protected]>,
> > jim beam <[email protected]> wrote:
> >
> >> sure, so
> >>
> >> http://www.flickr.com/photos/38636024@N00/101935519/
> >>
> >> is a fake?
> >
> > As I said earlier, it's impossible to tell if those are the salmon
> > pads or just the red pads, which are an inferior compound.
>
> this is the item i bought - and vendor from whom i did it.
>
> http://biketoolsetc.com/index.cgi?id=230161582707&d=single&c=Repair-Pa
> rts&sc=B rake&tc=Pads-Road&item_id=KS-C2SA
>
> there is no confusion.

To you, perhaps. However, your overt dislike for Jobst calls into
question the veracity of your statements. I question everything you
write because you seem so biased. I get the impression that you would
do whatever it takes to bring Jobst down a notch. Your behavior towards
him goes far beyond disagreeing with his ideas about bikes, and appears
to verge on hatred. It's intriguiing that you would have such a intense
negative cathexis towards someone you profess to have never met. Your
words say it's an impersonal disagreement, yet your actions say it's
personal.

Good price on those pads, BTW. Currently I am using this version of
Mathauser pads:

http://www.rivendellbicycles.com/webalog/brakes/15095.html

> >> "salmons are great because they don't embed grit" we are told by
> >> those with a vested interest in selling them. i've found this not
> >> to be true. "they stop well in the wet" we are told. i've found
> >> that not to be true also - and because i have the temerity to say
> >> so, that makes me untruthful?
> >
> > Just pointing out that your experience, as seems to frequently be
> > the case, is at odds with the rest of us.
>
> yes. and how many of you, and for how many years, blindly accepted
> jobst's engineering gaffes without question? mockery and ridicule
> don't make a naysayer incorrect - indeed such behavior frequently
> demonstrates the opposite since a factual rebuttal would be both much
> simpler and carry more weight.

As of this date, jim, you have yet to demonstrate the fallacy of Jobst's
engineering. You are convinced of your rightness, but it clearly seems
that no one else is except perhaps Carl Fogel on occasion.

As far as the KoolStop/Mathauser pads go, the consensus seems to be
against you both here in rec.bicycles.tech and elsewhere:

http://mtbr.com/reviews/Brake_Pad/product_20469.shtml

> > I've used these pads for years (got my first set of Mathausers in
> > the late 1970s) and have had no problems with the pads picking up
> > bits of rim material, and find them better in the rain than any
> > other brake pad I have tried. Interestingly there is objective
> > data to back up that subjective impression, as I mentioned.
>
> what's with the presumption that kool-stops are the same as the
> mathausers and therefore have the same properties? it's simply that
> - a presumption. i've questioned this point before, but so far, no
> one has been able to definitely illuminate.

Well, all I can go by is media reports by well-informed people (e.g.,
Sheldon Brown, Grant Petersen who do business with both) that KoolStop
makes the pads for Mathauser. To examination the material is the same
color and has the same tactile feel. I suppose you could contact
KoolStop and ask them for verification.

http://www.sheldonbrown.com/harris/brakeshoes.html

http://www.rivendellbicycles.com/webalog/brakes/15061.html

Jobst (not that you would believe him if he told you the sky was blue)
asked the KoolStop people about this, as mentioned in this post from
2/5/99:

> Talking to the KoolStop people at the annual bicycle trade show, I
> learned that it is a KoolStop formulation and that they make pads for
> most of the smaller brand brakes, including Matthauser.

Jobst was also critical of the old Mathauser brake compound in the same
post:

> The original Matthauser pads had a compound that melted and became
> dangerously gummy before failing entirely. I had some scary moments
> on these because they were insertable in Campagnolo holders and I had
> been told how good they were. I still have samples of these pads
> with obvious molten material on them. Subsequently Matthauser used
> KoolStop salmon compound that had previously been available but only
> in the Continental model, that did not have the wheel insertion ears
> of the Campagnolo brakes. That's when I changed to KoolStop and have
> not regretted it.

I used the neat-looking but uselessly finned Scott/Mathauser pads back
in the late 70s. Still have 'em somewhere, even though that bike has
been long gone for over 20 years. I didn't experience what Jobst
reported, but then I didn't live anywhere with descents longer than a
few minutes to put it to the test.

> >>> LOL. You're such a troll.
> >>
> >> no tim, i just don't like smoke being blown up my kilt. and i
> >> will call out anyone that tries to do so.
> >
> > "Call out?" What is this, the OK Corral? LOL! Perhaps you should
> > change your handle from "jim beam" to "pale rider."
>
> if dueling was legal, there wouldn't be as many liars and
> bullshitters in the world. and many lawyers would be unemployed.

That explains a lot about your mentality.

 

[jim beam]

Tim McNamara wrote:
> In article <[email protected]>,
> jim beam <[email protected]> wrote:
>
>> Tim McNamara wrote:
>>> In article <[email protected]>,
>>> jim beam <[email protected]> wrote:
>>>
>>>> sure, so
>>>>
>>>> http://www.flickr.com/photos/38636024@N00/101935519/
>>>>
>>>> is a fake?
>>> As I said earlier, it's impossible to tell if those are the salmon
>>> pads or just the red pads, which are an inferior compound.
>> this is the item i bought - and vendor from whom i did it.
>>
>> http://biketoolsetc.com/index.cgi?id=230161582707&d=single&c=Repair-Pa
>> rts&sc=B rake&tc=Pads-Road&item_id=KS-C2SA
>>
>> there is no confusion.
>
> To you, perhaps. However, your overt dislike for Jobst calls into
> question the veracity of your statements. I question everything you
> write because you seem so biased. I get the impression that you would
> do whatever it takes to bring Jobst down a notch. Your behavior towards
> him goes far beyond disagreeing with his ideas about bikes, and appears
> to verge on hatred. It's intriguiing that you would have such a intense
> negative cathexis towards someone you profess to have never met. Your
> words say it's an impersonal disagreement, yet your actions say it's
> personal.

so what are you evidencing right now? bottom line, you don't know
enough about the subject matter to know when you're being bullshitted.
how you can use that foundation of ignorance as a basis for criticism is
beyond my comprehension.

>
> Good price on those pads, BTW. Currently I am using this version of
> Mathauser pads:
>
> http://www.rivendellbicycles.com/webalog/brakes/15095.html
>
>>>> "salmons are great because they don't embed grit" we are told by
>>>> those with a vested interest in selling them. i've found this not
>>>> to be true. "they stop well in the wet" we are told. i've found
>>>> that not to be true also - and because i have the temerity to say
>>>> so, that makes me untruthful?
>>> Just pointing out that your experience, as seems to frequently be
>>> the case, is at odds with the rest of us.
>> yes. and how many of you, and for how many years, blindly accepted
>> jobst's engineering gaffes without question? mockery and ridicule
>> don't make a naysayer incorrect - indeed such behavior frequently
>> demonstrates the opposite since a factual rebuttal would be both much
>> simpler and carry more weight.
>
> As of this date, jim, you have yet to demonstrate the fallacy of Jobst's
> engineering.

tim, why do you keep on demonstrating such blind willful stubborn
pig-headed ignorance? don't you understand anything you read? you're
the guy that argued that a 1000N load was dangerous on a fork that can
easily retain 3000N - you're just so far off base, it's jaw-dropping.

brief recap of some jobstian fallacies, in random order:

1. spokes have high levels of residual stress. unproven, but easily
tested. testing never done.
2. rims crack because of anodizing. false - rim cracks do not follow
anodizing cracks.
3. wheels increase in strength as spoke tension increases. false.
tensile strength is "borrowed" from one component and added to the
compressive side of the graph of the other, but there is no net increase.
4. fatigue can be eliminated from spokes. false. stainless steels have
no endurance limit.
5. spoke gauge does not affect tensiometer deflection. false.
6. bike bearings are elasto-hydrodynamically separated. false.
7. fracture is a function of cross sectional area. "confused". in
static load, yes. in fatigue, no. jobst apparently has never heard of
the concepts determining crack tip behavior.
8. headset bearings cannot be brinneled. false.
9. bmw's "whoosh" because their bearings are damaged in shipping. false.
10. "stress relief" occurs in a region of the stress/strain graph where
there is deformation without work hardening. false. stainless and high
tensile steels don't exhibit this behavior.

etc.

> You are convinced of your rightness, but it clearly seems
> that no one else is except perhaps Carl Fogel on occasion.
>
> As far as the KoolStop/Mathauser pads go, the consensus seems to be
> against you both here in rec.bicycles.tech and elsewhere:
>
> http://mtbr.com/reviews/Brake_Pad/product_20469.shtml

heh. ever heard of astroturf? i've been approached by certain
individuals to write "user endorsements" of products on that site. how
many others are there? that behavior doesn't do much for credibility imo.

>
>>> I've used these pads for years (got my first set of Mathausers in
>>> the late 1970s) and have had no problems with the pads picking up
>>> bits of rim material, and find them better in the rain than any
>>> other brake pad I have tried. Interestingly there is objective
>>> data to back up that subjective impression, as I mentioned.
>> what's with the presumption that kool-stops are the same as the
>> mathausers and therefore have the same properties? it's simply that
>> - a presumption. i've questioned this point before, but so far, no
>> one has been able to definitely illuminate.
>
> Well, all I can go by is media reports by well-informed people (e.g.,
> Sheldon Brown, Grant Petersen who do business with both) that KoolStop
> makes the pads for Mathauser. To examination the material is the same
> color and has the same tactile feel. I suppose you could contact
> KoolStop and ask them for verification.

so could you. you're the one making the assumption, i'm not.

>
> http://www.sheldonbrown.com/harris/brakeshoes.html
>
> http://www.rivendellbicycles.com/webalog/brakes/15061.html
>
> Jobst (not that you would believe him if he told you the sky was blue)
> asked the KoolStop people about this, as mentioned in this post from
> 2/5/99:
>
>> Talking to the KoolStop people at the annual bicycle trade show, I
>> learned that it is a KoolStop formulation and that they make pads for
>> most of the smaller brand brakes, including Matthauser.
>
> Jobst was also critical of the old Mathauser brake compound in the same
> post:
>
>> The original Matthauser pads had a compound that melted and became
>> dangerously gummy before failing entirely. I had some scary moments
>> on these because they were insertable in Campagnolo holders and I had
>> been told how good they were. I still have samples of these pads
>> with obvious molten material on them. Subsequently Matthauser used
>> KoolStop salmon compound that had previously been available but only
>> in the Continental model, that did not have the wheel insertion ears
>> of the Campagnolo brakes. That's when I changed to KoolStop and have
>> not regretted it.
>
> I used the neat-looking but uselessly finned Scott/Mathauser pads back
> in the late 70s. Still have 'em somewhere, even though that bike has
> been long gone for over 20 years. I didn't experience what Jobst
> reported, but then I didn't live anywhere with descents longer than a
> few minutes to put it to the test.

entertaining little red herring. it still won't get you over the
evidence of salmon pads and embedded grit tim.

>
>>>>> LOL. You're such a troll.
>>>> no tim, i just don't like smoke being blown up my kilt. and i
>>>> will call out anyone that tries to do so.
>>> "Call out?" What is this, the OK Corral? LOL! Perhaps you should
>>> change your handle from "jim beam" to "pale rider."
>> if dueling was legal, there wouldn't be as many liars and
>> bullshitters in the world. and many lawyers would be unemployed.
>
> That explains a lot about your mentality.

i'd love an explanation of the mentality that is willfully, stubbornly
and utterly blind to fact.

 

[Tim McNamara]

In article <[email protected]>,
jim beam <[email protected]> wrote:

> Tim McNamara wrote:
> > In article <[email protected]>,
> > jim beam <[email protected]> wrote:
> >
> >> Tim McNamara wrote:
> >>> In article <[email protected]>,
> >>> jim beam <[email protected]> wrote:
> >>>
> >>>> sure, so
> >>>>
> >>>> http://www.flickr.com/photos/38636024@N00/101935519/
> >>>>
> >>>> is a fake?
> >>> As I said earlier, it's impossible to tell if those are the
> >>> salmon pads or just the red pads, which are an inferior compound.
> >> this is the item i bought - and vendor from whom i did it.
> >>
> >> http://biketoolsetc.com/index.cgi?id=230161582707&d=single&c=Repair
> >> -Pa rts&sc=B rake&tc=Pads-Road&item_id=KS-C2SA
> >>
> >> there is no confusion.
> >
> > To you, perhaps. However, your overt dislike for Jobst calls into
> > question the veracity of your statements. I question everything
> > you write because you seem so biased. I get the impression that
> > you would do whatever it takes to bring Jobst down a notch. Your
> > behavior towards him goes far beyond disagreeing with his ideas
> > about bikes, and appears to verge on hatred. It's intriguiing that
> > you would have such a intense negative cathexis towards someone you
> > profess to have never met. Your words say it's an impersonal
> > disagreement, yet your actions say it's personal.
>
> so what are you evidencing right now? bottom line, you don't know
> enough about the subject matter to know when you're being
> bullshitted. how you can use that foundation of ignorance as a basis
> for criticism is beyond my comprehension.

It's simple enough, even for you. I use the product. I've used them in
all weathers locally and in the Alps, where they worked great. But it
only rained for about 5 minutes out of the 10 days I was in the Alps, so
I can't comment on how the pads would work riding down a mountain in the
rain. My brake pads certainly worked better than the horrible Shimano
pads being used by my friend.

> > Good price on those pads, BTW. Currently I am using this version
> > of Mathauser pads:
> >
> > http://www.rivendellbicycles.com/webalog/brakes/15095.html
> >
> >>>> "salmons are great because they don't embed grit" we are told by
> >>>> those with a vested interest in selling them. i've found this
> >>>> not to be true. "they stop well in the wet" we are told. i've
> >>>> found that not to be true also - and because i have the temerity
> >>>> to say so, that makes me untruthful?
> >>> Just pointing out that your experience, as seems to frequently be
> >>> the case, is at odds with the rest of us.
> >> yes. and how many of you, and for how many years, blindly
> >> accepted jobst's engineering gaffes without question? mockery and
> >> ridicule don't make a naysayer incorrect - indeed such behavior
> >> frequently demonstrates the opposite since a factual rebuttal
> >> would be both much simpler and carry more weight.
> >
> > As of this date, jim, you have yet to demonstrate the fallacy of
> > Jobst's engineering.
>
> tim, why do you keep on demonstrating such blind willful stubborn
> pig-headed ignorance? don't you understand anything you read?
> you're the guy that argued that a 1000N load was dangerous on a fork
> that can easily retain 3000N - you're just so far off base, it's
> jaw-dropping.

You'll have to refresh my memory on that. If you're referring to my
calculations regarding the ejection force created by disc brakes versus
the retention force offered by skewers, I just used the readily
available numbers and simple math. And I allowed that the calculations
could be incorrect, and asked for correction of that was the case. You
offered none, but a real engineer pointed out that I had made a mistake
which underestimated the degree to which the ejection force could
overcome the retention force.

> brief recap of some jobstian fallacies, in random order:
>
> 1. spokes have high levels of residual stress. unproven, but easily
> tested. testing never done. 2. rims crack because of anodizing.
> false - rim cracks do not follow anodizing cracks. 3. wheels increase
> in strength as spoke tension increases. false. tensile strength is
> "borrowed" from one component and added to the compressive side of
> the graph of the other, but there is no net increase. 4. fatigue can
> be eliminated from spokes. false. stainless steels have no
> endurance limit. 5. spoke gauge does not affect tensiometer
> deflection. false. 6. bike bearings are elasto-hydrodynamically
> separated. false. 7. fracture is a function of cross sectional area.
> "confused". in static load, yes. in fatigue, no. jobst apparently
> has never heard of the concepts determining crack tip behavior. 8.
> headset bearings cannot be brinneled. false. 9. bmw's "whoosh"
> because their bearings are damaged in shipping. false. 10. "stress
> relief" occurs in a region of the stress/strain graph where there is
> deformation without work hardening. false. stainless and high
> tensile steels don't exhibit this behavior.

LOL. You've either wilfully misconstrued, taken out of context, or just
plain gotten it wrong. When all else fails you resort to obfuscation.
Isn't it odd that the real mechanical engineers in this newsgroup never
rush to your defense? Why would that be?

> > You are convinced of your rightness, but it clearly seems
> > that no one else is except perhaps Carl Fogel on occasion.
> >
> > As far as the KoolStop/Mathauser pads go, the consensus seems to be
> > against you both here in rec.bicycles.tech and elsewhere:
> >
> > http://mtbr.com/reviews/Brake_Pad/product_20469.shtml
>
> heh. ever heard of astroturf? i've been approached by certain
> individuals to write "user endorsements" of products on that site.
> how many others are there? that behavior doesn't do much for
> credibility imo.

Come back from LaLa Land, jim! Earth is calling!

> >>> I've used these pads for years (got my first set of Mathausers in
> >>> the late 1970s) and have had no problems with the pads picking up
> >>> bits of rim material, and find them better in the rain than any
> >>> other brake pad I have tried. Interestingly there is objective
> >>> data to back up that subjective impression, as I mentioned.
> >> what's with the presumption that kool-stops are the same as the
> >> mathausers and therefore have the same properties? it's simply
> >> that - a presumption. i've questioned this point before, but so
> >> far, no one has been able to definitely illuminate.
> >
> > Well, all I can go by is media reports by well-informed people
> > (e.g., Sheldon Brown, Grant Petersen who do business with both)
> > that KoolStop makes the pads for Mathauser. To examination the
> > material is the same color and has the same tactile feel. I
> > suppose you could contact KoolStop and ask them for verification.
>
> so could you. you're the one making the assumption, i'm not.

You're the one challenging it. The onus is on you.

> > http://www.sheldonbrown.com/harris/brakeshoes.html
> >
> > http://www.rivendellbicycles.com/webalog/brakes/15061.html
> >
> > Jobst (not that you would believe him if he told you the sky was
> > blue) asked the KoolStop people about this, as mentioned in this
> > post from 2/5/99:
> >
> >> Talking to the KoolStop people at the annual bicycle trade show, I
> >> learned that it is a KoolStop formulation and that they make pads
> >> for most of the smaller brand brakes, including Matthauser.
> >
> > Jobst was also critical of the old Mathauser brake compound in the
> > same post:
> >
> >> The original Matthauser pads had a compound that melted and became
> >> dangerously gummy before failing entirely. I had some scary
> >> moments on these because they were insertable in Campagnolo
> >> holders and I had been told how good they were. I still have
> >> samples of these pads with obvious molten material on them.
> >> Subsequently Matthauser used KoolStop salmon compound that had
> >> previously been available but only in the Continental model, that
> >> did not have the wheel insertion ears of the Campagnolo brakes.
> >> That's when I changed to KoolStop and have not regretted it.
> >
> > I used the neat-looking but uselessly finned Scott/Mathauser pads
> > back in the late 70s. Still have 'em somewhere, even though that
> > bike has been long gone for over 20 years. I didn't experience
> > what Jobst reported, but then I didn't live anywhere with descents
> > longer than a few minutes to put it to the test.
>
> entertaining little red herring. it still won't get you over the
> evidence of salmon pads and embedded grit tim.

Well, jim, since I've never had that happen with my use of those pads
for decades, I think the problem is not mine. It's yours. And as I've
said, I basically don't believe just about anything you write, so I
don;t buy your claims about those pads. I think you're a liar and a
fraud.

> >>>>> LOL. You're such a troll.
> >>>> no tim, i just don't like smoke being blown up my kilt. and i
> >>>> will call out anyone that tries to do so.
> >>> "Call out?" What is this, the OK Corral? LOL! Perhaps you
> >>> should change your handle from "jim beam" to "pale rider."
> >> if dueling was legal, there wouldn't be as many liars and
> >> bullshitters in the world. and many lawyers would be unemployed.
> >
> > That explains a lot about your mentality.
>
> i'd love an explanation of the mentality that is willfully,
> stubbornly and utterly blind to fact.

I prefer facts that are demonstrable, not factoids based on unproven
claims or misapplied principles. Your claims are typically not proven
except on rare occasion (and, though you've failed to notice, I agree
with you on those occasions). Your habit is to make a claim and then
argue that it is proven because no one has disproven it, which is shitty
science. That you routinely fail to prove your own claims escapes you
in your pathetic desperation to beat Jobst. You turn a deaf ear to
anyone who disagrees with you and ignore that reality is not on your
side.

 

[jim beam]

Tim McNamara wrote:
<snip rant>

tim, you believe whatever you want, but faith-based engineering doesn't
fly in the real world. meanwhile, i'll do some math, post some facts
and post some evidence. you just keep on flinging your teddy in the
corner - that'll really be a significant contribution.

 

[Johnny Sunset aka Tom Sherman]

jim beam wrote:
> Tim McNamara wrote:
> <snip rant>
>
> tim, you believe whatever you want, but faith-based engineering doesn't
> fly in the real world. meanwhile, i'll do some math, post some facts
> and post some evidence. you just keep on flinging your teddy in the
> corner - that'll really be a significant contribution.

Questions for "jim beam".

Why are you afraid to use your real name?

Does your keyboard lack "Shift" keys or is your newsreader capital
letter deficient?

What is your real problem with Jobst Brandt?

--
Tom Sherman - Here, not there.

 

[jim beam]

Johnny Sunset aka Tom Sherman wrote:
> jim beam wrote:
>> Tim McNamara wrote:
>> <snip rant>
>>
>> tim, you believe whatever you want, but faith-based engineering doesn't
>> fly in the real world. meanwhile, i'll do some math, post some facts
>> and post some evidence. you just keep on flinging your teddy in the
>> corner - that'll really be a significant contribution.
>
> Questions for "jim beam".
>
> Why are you afraid to use your real name?

who says that's not my real name? call me "james" if you want - my
mother does. you can also call me "lisa" if it'll make you feel better.

>
> Does your keyboard lack "Shift" keys or is your newsreader capital
> letter deficient?

no, it's a flaw in my scripting algorithm.

>
> What is your real problem with Jobst Brandt?
>

i don't understand anyone that /doesn't/ have a problem with jobst
brandt. he knows nothing about fatigue or fracture, but he presumes to
lecture on those subjects like a drunken sailor on the subject of
romance. his engineering isn't much better either. admittedly, his
style of ad hominem appears to entertain the peanut gallery, but that
still doesn't make for fatigue elimination in a material with no
endurance limit, and it doesn't make tensiometer deflection immune to
spoke gauge. assumption masquerading as fact may be inconsequential to
most, but to those of us that know different, it's wretched to behold.

 

[Dane Buson]

Johnny Sunset aka Tom Sherman <[email protected]> wrote:
>
> Does your keyboard lack "Shift" keys or is your newsreader capital
> letter deficient?

Now, now, in a thread earlier this year I actually saw him use a capital
letter. I think it's more a matter of willful disobedience of that
particular grammatical rule. Perhaps he was bitten by an English
teacher when he was young?

--
Dane Buson - [email protected]
Yesterday upon the stair
I met a man who wasn't there.
He wasn't there again today --
I think he's from the CIA.

 

[Tim McNamara]

In article <[email protected]>,
jim beam <[email protected]> wrote:

> Tim McNamara wrote: <snip rant>
>
> tim, you believe whatever you want, but faith-based engineering
> doesn't fly in the real world. meanwhile, i'll do some math, post
> some facts and post some evidence. you just keep on flinging your
> teddy in the corner - that'll really be a significant contribution.

Do whatever it is you think you do, jim. When the people in this
newsgroup who really are engineers agree with you. I'll take notice. As
you've pointed out in the past, you're no engineer.

 

[[email protected]]

On Fri, 15 Sep 2006 09:18:02 -0500, Tim McNamara
<[email protected]> wrote:

>In article <[email protected]>,
> jim beam <[email protected]> wrote:
>
>> Tim McNamara wrote: <snip rant>
>>
>> tim, you believe whatever you want, but faith-based engineering
>> doesn't fly in the real world. meanwhile, i'll do some math, post
>> some facts and post some evidence. you just keep on flinging your
>> teddy in the corner - that'll really be a significant contribution.
>
>Do whatever it is you think you do, jim. When the people in this
>newsgroup who really are engineers agree with you. I'll take notice. As
>you've pointed out in the past, you're no engineer.

He's also the guy who, when all else fails, thinks that trial by
combat is the way to decide issues of a mechanical nature.

 

[jim beam]

Tim McNamara wrote:
> In article <[email protected]>,
> jim beam <[email protected]> wrote:
>
>> Tim McNamara wrote: <snip rant>
>>
>> tim, you believe whatever you want, but faith-based engineering
>> doesn't fly in the real world. meanwhile, i'll do some math, post
>> some facts and post some evidence. you just keep on flinging your
>> teddy in the corner - that'll really be a significant contribution.
>
> Do whatever it is you think you do, jim. When the people in this
> newsgroup who really are engineers agree with you. I'll take notice. As
> you've pointed out in the past, you're no engineer.

no, i'm a[n ex] metallurgist. and an engineer posing as a metallurgist,
and getting it wrong, is wretched. almost as wretched as someone who is
neither, and who can't be bothered to read archives, presuming to
supplant fact with faith.

 

[David Damerell]

Quoting Johnny Sunset aka Tom Sherman <[email protected]>:
>Questions for "jim beam".
>Why are you afraid to use your real name?

"tux lover" won't even use his previous pseud.
--
OPTIONS=name:Kirsty,menustyle:C,female,lit_corridor,standout,time,showexp,hilit
e_pet,catname:Akane,dogname:Ryoga,fruitkonomiyaki,pickup_types:"!$?=/,scores:
5 top/2 around,color,boulder:0,autoquiver,autodig,disclose:yiyayvygyc,pickup_bu
rden:burdened,!cmdassist,msg_window:reversed,!sparkle,horsename:Rumiko,showrace

 

[Peter Cole]

jim beam wrote:
>
> brief recap of some jobstian fallacies, in random order:
>
> 1. spokes have high levels of residual stress. unproven, but easily
> tested. testing never done.

> 4. fatigue can be eliminated from spokes. false. stainless steels have
> no endurance limit.

From <http://www.stal.com.cn/pdffile/302304304l305.pdf>

"Stresses may result from cold deformation of the alloy during
forming, or by roller expanding tubes into tubesheets,
or by welding operations which produce stresses from
the thermal cycles used. Stress levels may be
reduced by annealing or stress relieving heat treat-
ments following cold deformation,"

And

"The fatigue strength or endurance limit is the maxi-
mum stress below which material is unlikely to fail in
10 million cycles in air environment. The fatigue strength for
austenitic stainless steels, as a group, is typically about 35 percent
of the tensile strength."

 

[Peter Cole]

jim beam wrote:
> brief recap of some jobstian fallacies, in random order:
>

> 3. wheels increase in strength as spoke tension increases. false.
> tensile strength is "borrowed" from one component and added to the
> compressive side of the graph of the other, but there is no net increase.

The stiffness of the spokes and rim add. When the spoke is detensioned
from load the wheel is less stiff. The effect is identical to 2 springs
in parallel.

 

[Peter Cole]

jim beam wrote:
> brief recap of some jobstian fallacies, in random order:

> 10. "stress relief" occurs in a region of the stress/strain graph where
> there is deformation without work hardening. false. stainless and high
> tensile steels don't exhibit this behavior.

There is no (plastic) deformation in spoke stress relief.

 

[Michael Press]

In article
<[email protected]>,
Peter Cole <[email protected]> wrote:

> jim beam wrote:
> > brief recap of some jobstian fallacies, in random order:
>
> > 10. "stress relief" occurs in a region of the stress/strain graph where
> > there is deformation without work hardening. false. stainless and high
> > tensile steels don't exhibit this behavior.
>
> There is no (plastic) deformation in spoke stress relief.

What is stress relief, then?

It is plastic deformation of certain portions of the spoke
that have built in stress; those portions where the built
in stress plus spoke tension take that portion past the
fatigue strength.

--
Michael Press

 

[Peter Cole]

Michael Press wrote:
> In article
> <[email protected]>,
> Peter Cole <[email protected]> wrote:
>
>> jim beam wrote:
>>> brief recap of some jobstian fallacies, in random order:
>>> 10. "stress relief" occurs in a region of the stress/strain graph where
>>> there is deformation without work hardening. false. stainless and high
>>> tensile steels don't exhibit this behavior.
>> There is no (plastic) deformation in spoke stress relief.
>
> What is stress relief, then?
>
> It is plastic deformation of certain portions of the spoke
> that have built in stress; those portions where the built
> in stress plus spoke tension take that portion past the
> fatigue strength.
>

Yes, I meant overall deformation (elongation).

 

[Joe Riel]

Peter Cole <[email protected]> writes:

> The stiffness of the spokes and rim add. When the spoke is detensioned
> from load the wheel is less stiff. The effect is identical to 2
> springs in parallel.

What do you mean by "detensioned"? If you mean reducing the tension
to zero, then, yes, the wheel becomes less stiff at that point.
However, that isn't part of the normal operation of a wheel. The
minor detensioning in the lower spokes when the load is applied
does not affect the stiffness.

It isn't accurate to say that the rim and spokes act as parallel
springs. If anything, they act more as series springs.

--
Joe Riel

 

[Peter Cole]

Joe Riel wrote:
> Peter Cole <[email protected]> writes:
>
>> The stiffness of the spokes and rim add. When the spoke is detensioned
>> from load the wheel is less stiff. The effect is identical to 2
>> springs in parallel.
>
> What do you mean by "detensioned"? If you mean reducing the tension
> to zero, then, yes, the wheel becomes less stiff at that point.

That is what I meant.

> However, that isn't part of the normal operation of a wheel. The
> minor detensioning in the lower spokes when the load is applied
> does not affect the stiffness.

In this context (which you deleted) of wheel strength, it takes more
load to detension the spokes if the spoke tension is higher -- hence,
the wheel is stronger.


>
> It isn't accurate to say that the rim and spokes act as parallel
> springs. If anything, they act more as series springs.
>

If this were true then the combination of spoke and rim "springs" would
be less stiff than either individual component, yet the combination is
more stiff -- at least until the spoke becomes detensioned by load. In
that way, the combination acts as springs in parallel, not series.

 

[Joe Riel]

Peter Cole <[email protected]> writes:

> Joe Riel wrote:

[...]

>> It isn't accurate to say that the rim and spokes act as parallel
>> springs. If anything, they act more as series springs.
>>
>
> If this were true then the combination of spoke and rim "springs"
> would be less stiff than either individual component, yet the
> combination is more stiff -- at least until the spoke becomes
> detensioned by load. In that way, the combination acts as springs in
> parallel, not series.

You are correct. I got confused thinking about the mechanical
arrangement. Thanks.

--
Joe Riel