J
jim beam
Guest
[email protected] wrote:
> On Feb 14, 12:48 am, jim beam <[email protected]> wrote:
>> [email protected] wrote:
>>> EP and jb go on about initial conditions not being verified (or some
>>> such thing) without ever specifying what they'd accept as a standard
>>> for verification. Obviously, the procedures normally used (such as
>>> clamp angle of the QR) don't qualify in their eyes.
>>> They give the impression the only accepted testimony involves QRs
>>> tightened with a torque wrench whose resolution is 0.1 inch-pounds.
>>> Then checked again at the bottom of a suitable descent. With the
>>> entire process done in front of three witnesses. Who sign a document
>>> of testimony. Which is notarized.
>> classic krygowski getting red herringed. torque wrench means nothing
>> across different qr's since friction on each is different.
>
> That's even better, jim.
>
> Previously, you've implied gaging proper QR installation by clamp
> angle, as usually advised (90 degrees, 80 degrees, etc.) isn't valid.
> Now you say even the amount of torque applied to the QR can't prove
> it's been properly fastened.
for a mechanical engineering professor, you're either a damned idiot or
you're contributing to mcnamara's gullibility thesis research. and
don't put words in my mouth.
baby steps:
torque is a function of friction. friction is not constant. friction
varies from skewer to skewer, from design to design. torque is
therefore useless.
angle is a function of elasticity. elasticity varies according to
materials and physical dimensions. but angle can be more reliable than
torque for any given skewer since friction is not a factor.
>
> In effect, that means there is _no_ practical way of telling if the QR
> is clamped properly. That's certainly a handy state of affairs for a
> guy who wants to blame all failures on user error!
torque sure isn't the way to do it! and whoops, the engineering
professor needs to clue in on how vehicle head bolts are tightened these
days - final stage is angle tightening. idiot.
>
>> all that matters is indention, since that's what generates retention force.
>
> And how is one to gage "indentation"? Release the QR and look for
> marks? Obviously, that's testing ex post facto. It does nothing for
> a person intending to leave the QR clamped and ride.
do indentations disappear after each fastening? no. do indentations
get "reused"? yes. therefore, apart from the fact that initial
indentations proved the skewer was tightened sufficiently, their
subsequent reuse ensures continued retention. how did you get your job,
idiot?
>
> This doesn't even treat the fact that you've never specified a
> specific depth of indentation. Is 0.010" enough? How about 0.005"?
> How about 0.001"? And how will that be measured in the field?
er, have you never heard about shear? idiot.
>
> Furthermore, any indentation being examined might be from a previous
> installation of the QR, not the current one - which may be adjusted
> differently. (In fact, if a deeper previous indentation exists, the
> current installation may be tightened on flat surfaces adjacent to
> that indentation, but slip into it due to motion induced by impacts.
> When that happens, skewer tension _decreases_.)
my, what a short memory you have - that's been discussed before.
indenter profile ensures the same indent holes get "reused" repeatedly.
and that improves retention over time. idiot.
>
> You've shown your hand. Your standard for disproving user error is
> purposely unattainable. Therefore, you will never accept any failure
> account as anything but user error. Your bias is total and complete.
>
the charitable explanation for your making that statement might be that
you're ignoring many elephants in the room. of course, the other is
that you're an idiot.
> On Feb 14, 12:48 am, jim beam <[email protected]> wrote:
>> [email protected] wrote:
>>> EP and jb go on about initial conditions not being verified (or some
>>> such thing) without ever specifying what they'd accept as a standard
>>> for verification. Obviously, the procedures normally used (such as
>>> clamp angle of the QR) don't qualify in their eyes.
>>> They give the impression the only accepted testimony involves QRs
>>> tightened with a torque wrench whose resolution is 0.1 inch-pounds.
>>> Then checked again at the bottom of a suitable descent. With the
>>> entire process done in front of three witnesses. Who sign a document
>>> of testimony. Which is notarized.
>> classic krygowski getting red herringed. torque wrench means nothing
>> across different qr's since friction on each is different.
>
> That's even better, jim.
>
> Previously, you've implied gaging proper QR installation by clamp
> angle, as usually advised (90 degrees, 80 degrees, etc.) isn't valid.
> Now you say even the amount of torque applied to the QR can't prove
> it's been properly fastened.
for a mechanical engineering professor, you're either a damned idiot or
you're contributing to mcnamara's gullibility thesis research. and
don't put words in my mouth.
baby steps:
torque is a function of friction. friction is not constant. friction
varies from skewer to skewer, from design to design. torque is
therefore useless.
angle is a function of elasticity. elasticity varies according to
materials and physical dimensions. but angle can be more reliable than
torque for any given skewer since friction is not a factor.
>
> In effect, that means there is _no_ practical way of telling if the QR
> is clamped properly. That's certainly a handy state of affairs for a
> guy who wants to blame all failures on user error!
torque sure isn't the way to do it! and whoops, the engineering
professor needs to clue in on how vehicle head bolts are tightened these
days - final stage is angle tightening. idiot.
>
>> all that matters is indention, since that's what generates retention force.
>
> And how is one to gage "indentation"? Release the QR and look for
> marks? Obviously, that's testing ex post facto. It does nothing for
> a person intending to leave the QR clamped and ride.
do indentations disappear after each fastening? no. do indentations
get "reused"? yes. therefore, apart from the fact that initial
indentations proved the skewer was tightened sufficiently, their
subsequent reuse ensures continued retention. how did you get your job,
idiot?
>
> This doesn't even treat the fact that you've never specified a
> specific depth of indentation. Is 0.010" enough? How about 0.005"?
> How about 0.001"? And how will that be measured in the field?
er, have you never heard about shear? idiot.
>
> Furthermore, any indentation being examined might be from a previous
> installation of the QR, not the current one - which may be adjusted
> differently. (In fact, if a deeper previous indentation exists, the
> current installation may be tightened on flat surfaces adjacent to
> that indentation, but slip into it due to motion induced by impacts.
> When that happens, skewer tension _decreases_.)
my, what a short memory you have - that's been discussed before.
indenter profile ensures the same indent holes get "reused" repeatedly.
and that improves retention over time. idiot.
>
> You've shown your hand. Your standard for disproving user error is
> purposely unattainable. Therefore, you will never accept any failure
> account as anything but user error. Your bias is total and complete.
>
the charitable explanation for your making that statement might be that
you're ignoring many elephants in the room. of course, the other is
that you're an idiot.