MA3 rim failure, where to now

Tim McNamara writes:

And for the reasons that I and other have delineated, it is reasonable
to use the term "stands" in this context. If you don't like it, you
don't have to use it. As far as your understanding goes, as Mr.
Feynman famously pointed out: if you can't express it in plain simple
language, you don't understand it yourself.

Indeed. And he himself has said it, so it's surely to his credit...

Look, I have this nice pair of stilts you might want to buy. They're
made of boiled spaghetti, so they're sure to support your weight. Just
stand on them and try.

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

Age equals angst multiplied by the speed of fright squared.
;; the Worlock

Tim McNamara writes:

And for the reasons that I and other have delineated, it is reasonable
to use the term "stands" in this context. If you don't like it, you
don't have to use it. As far as your understanding goes, as Mr.
Feynman famously pointed out: if you can't express it in plain simple
language, you don't understand it yourself.

Indeed. And he himself has said it, so it's surely to his credit...

Look, I have this nice pair of stilts you might want to buy. They're
made of boiled spaghetti, so they're sure to support your weight. Just
stand on them and try.

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

Age equals angst multiplied by the speed of fright squared.
;; the Worlock

Ian Smith typed


On Tue, 23 Sep 2003, Helen Deborah Vecht
wrote:

But I'm probably bluffing...

Bluffing or not, it's the right answer.

:-)

They did say education was what remained when you'd forgotten all you
crammed for exams...

--
Helen D. Vecht:
Edgware.

Ian Smith typed


On Tue, 23 Sep 2003, Helen Deborah Vecht
wrote:

But I'm probably bluffing...

Bluffing or not, it's the right answer.

:-)

They did say education was what remained when you'd forgotten all you
crammed for exams...

--
Helen D. Vecht:
Edgware.

Simon Brooke wrote:

I think you probably meant to say 'the bottom spokes undergo more
strain than the top ones'; if so, it's _not_ true, and is just
precisely the misunderstanding this 'stands on' nonsense leads to. The
bottom spokes at any given moment - those immediately above the
contact patch - experience the _least_ strain of all the spokes -
they're doing _least_ work. But they do, dynamically, experience the
greatest _change_ of strain as they move from being normally loaded at
about half-past-four to relatively highly loaded at five o'clock to
relatively unloaded at 6 o'clock to relatively highly loaded at 7
o'clock to normal again by half-past-seven.


No, I meant what I said.

As the load comes on the hub, the bottom spokes undergo more strain. Their
length is reduced compared what it would be in an unloaded state.

As a loaded wheels rotates the spokes exhibit a periodic pattern of strain,
with a sharp compressive strain as the spoke points straight down.

Of course this is supperimposed on a constant tensile stress and strain.

It is the periodic compressive stress that can cause fatigue.



--
Andy Morris

AndyAtJinkasDotFreeserve.Co.UK


Love this:
Put an end to Outlook Express's messy quotes
http://home.in.tum.de/~jain/software/oe-quotefix/

Simon Brooke wrote:

I think you probably meant to say 'the bottom spokes undergo more
strain than the top ones'; if so, it's _not_ true, and is just
precisely the misunderstanding this 'stands on' nonsense leads to. The
bottom spokes at any given moment - those immediately above the
contact patch - experience the _least_ strain of all the spokes -
they're doing _least_ work. But they do, dynamically, experience the
greatest _change_ of strain as they move from being normally loaded at
about half-past-four to relatively highly loaded at five o'clock to
relatively unloaded at 6 o'clock to relatively highly loaded at 7
o'clock to normal again by half-past-seven.


No, I meant what I said.

As the load comes on the hub, the bottom spokes undergo more strain. Their
length is reduced compared what it would be in an unloaded state.

As a loaded wheels rotates the spokes exhibit a periodic pattern of strain,
with a sharp compressive strain as the spoke points straight down.

Of course this is supperimposed on a constant tensile stress and strain.

It is the periodic compressive stress that can cause fatigue.



--
Andy Morris

AndyAtJinkasDotFreeserve.Co.UK


Love this:
Put an end to Outlook Express's messy quotes
http://home.in.tum.de/~jain/software/oe-quotefix/

Helen Deborah Vecht wrote:
Simon Brooke typed


"AndyMorris" writes:

Simon Brooke wrote:

Even if you still think you're right and we're wrong, you still
should not use this terminology because it obviously
miscommunicates with a substantial subset of you audience.

[snip]

To say that a hub stands on the bottom spokes suggests that the
bottom spokes undergo more strain than the bottom ones, this is
true.

I think you probably meant to say 'the bottom spokes undergo more
strain than the top ones';

To many engineers the term 'strain' has a very different meaning to
that of 'stress'.

It is a very long time since I did my Physics A Level (1976) but I
vaguely remember the Young modulus (measuring stiffness) being
stress/strain. Stress was the force being applied to something and
strain its deformation.

These words would be used interchangeably in 'ordinary English' but
have very different meanings in this sort of context. It strikes me
that the lowermost spokes might be under 'most strain' because they
deform most at the bottom of the cycle but that the tension in a
spoke would be maximum (only minimally) at the top.

But I'm probably bluffing...

Spot on helly, I did listen a little at the mech eng.

--
Andy Morris

AndyAtJinkasDotFreeserve.Co.UK


Love this:
Put an end to Outlook Express's messy quotes
http://home.in.tum.de/~jain/software/oe-quotefix/

Helen Deborah Vecht wrote:
Simon Brooke typed


"AndyMorris" writes:

Simon Brooke wrote:

Even if you still think you're right and we're wrong, you still
should not use this terminology because it obviously
miscommunicates with a substantial subset of you audience.

[snip]

To say that a hub stands on the bottom spokes suggests that the
bottom spokes undergo more strain than the bottom ones, this is
true.

I think you probably meant to say 'the bottom spokes undergo more
strain than the top ones';

To many engineers the term 'strain' has a very different meaning to
that of 'stress'.

It is a very long time since I did my Physics A Level (1976) but I
vaguely remember the Young modulus (measuring stiffness) being
stress/strain. Stress was the force being applied to something and
strain its deformation.

These words would be used interchangeably in 'ordinary English' but
have very different meanings in this sort of context. It strikes me
that the lowermost spokes might be under 'most strain' because they
deform most at the bottom of the cycle but that the tension in a
spoke would be maximum (only minimally) at the top.

But I'm probably bluffing...

Spot on helly, I did listen a little at the mech eng.

--
Andy Morris

AndyAtJinkasDotFreeserve.Co.UK


Love this:
Put an end to Outlook Express's messy quotes
http://home.in.tum.de/~jain/software/oe-quotefix/

Simon Brooke wrote:

Look, I have this nice pair of stilts you might want to buy. They're
made of boiled spaghetti, so they're sure to support your weight. Just
stand on them and try.

Hmm. That sentence demonstrates that Simon has failed to understand the
many lines of lucid explanation of the bicycle wheel that have been
offered to him.

What was that about Simple Simon again?

--
Ted Bennett
Portland OR

Simon Brooke wrote:

Look, I have this nice pair of stilts you might want to buy. They're
made of boiled spaghetti, so they're sure to support your weight. Just
stand on them and try.

Hmm. That sentence demonstrates that Simon has failed to understand the
many lines of lucid explanation of the bicycle wheel that have been
offered to him.

What was that about Simple Simon again?

--
Ted Bennett
Portland OR