x-post: Bike Biz: Wheel ejection theory goes legal

On Feb 12, 8:58 pm, Tim McNamara wrote:
In article . com,
"Ed Pirrero" wrote:





On Feb 12, 3:02 pm, "G.T." wrote:
"Ed Pirrero" wrote in message

roups.com...

On Feb 12, 2:27 pm, "G.T." wrote:
"Ed Pirrero" wrote in message

roups.com...

On Feb 11, 7:54 pm, Gary Young wrote:

This is a variant of the
my-uncle-was-a-smoker-and-he-lived-until-95 argument.

Except for the small details that smoking will most definitely
cause some harm, and, so far, disk brakes have caused none due
to the ejection force being present.

None? You're sure about that?

Greg

The answer to both questions is in the part you trimmed.

"(Qualifier: if some harm has occurred, it certainly hasn't been
distinguished from user error.)"

So now you're omniscient?

Strawman.

If you've got any, and I mean ANY, credible data that any of the
incidents involving wheel ejection have been proven as disk-brake
caused, go ahead and cite it.

Define "credible." As far as I can tell, you consider no report
credible that contradicts your theory.- Hide quoted text -

Credible includes where the initial conditions are known and verified.

"Somebody said so" isn't data, Tim. Never has been, never will be.

E.P.

Ed Pirrero wrote:
On Feb 12, 8:58 pm, Tim McNamara wrote:
In article . com,
"Ed Pirrero" wrote:





On Feb 12, 3:02 pm, "G.T." wrote:
"Ed Pirrero" wrote in message
oups.com...
On Feb 12, 2:27 pm, "G.T." wrote:
"Ed Pirrero" wrote in message
ups.com...
On Feb 11, 7:54 pm, Gary Young wrote:
This is a variant of the
my-uncle-was-a-smoker-and-he-lived-until-95 argument.
Except for the small details that smoking will most definitely
cause some harm, and, so far, disk brakes have caused none due
to the ejection force being present.
None? You're sure about that?
Greg
The answer to both questions is in the part you trimmed.
"(Qualifier: if some harm has occurred, it certainly hasn't been
distinguished from user error.)"
So now you're omniscient?
Strawman.
If you've got any, and I mean ANY, credible data that any of the
incidents involving wheel ejection have been proven as disk-brake
caused, go ahead and cite it.
Define "credible." As far as I can tell, you consider no report
credible that contradicts your theory.- Hide quoted text -

Credible includes where the initial conditions are known and verified.

"Somebody said so" isn't data, Tim. Never has been, never will be.


So you need, what, 17.5 people including the Pope to check that
someone's QR was tight before you'll believe any of these people?

Greg

--
"All my time I spent in heaven
Revelries of dance and wine
Waking to the sound of laughter
Up I'd rise and kiss the sky" - The Mekons

On Feb 13, 9:24 am, "G.T." wrote:
Ed Pirrero wrote:
On Feb 12, 8:58 pm, Tim McNamara wrote:
In article . com,
"Ed Pirrero" wrote:

On Feb 12, 3:02 pm, "G.T." wrote:
"Ed Pirrero" wrote in message
legroups.com...
On Feb 12, 2:27 pm, "G.T." wrote:
"Ed Pirrero" wrote in message
glegroups.com...
On Feb 11, 7:54 pm, Gary Young wrote:
This is a variant of the
my-uncle-was-a-smoker-and-he-lived-until-95 argument.
Except for the small details that smoking will most definitely
cause some harm, and, so far, disk brakes have caused none due
to the ejection force being present.
None? You're sure about that?
Greg
The answer to both questions is in the part you trimmed.
"(Qualifier: if some harm has occurred, it certainly hasn't been
distinguished from user error.)"
So now you're omniscient?
Strawman.
If you've got any, and I mean ANY, credible data that any of the
incidents involving wheel ejection have been proven as disk-brake
caused, go ahead and cite it.
Define "credible." As far as I can tell, you consider no report
credible that contradicts your theory.- Hide quoted text -

Credible includes where the initial conditions are known and verified.

"Somebody said so" isn't data, Tim. Never has been, never will be.

So you need, what, 17.5 people including the Pope to check that
someone's QR was tight before you'll believe any of these people?

Greg, I realize that you're now just after some sort of ****ing match.

That's fine - I'm not going to play. Have the last word, if you'd
like.

E.P.

Ben C? writes:

As I said in another thread, if the difference in direction is 45
degrees or better, I don't think you're going to get ejection.
Unless my calculations are still wrong (it's been known...) Ben
Micklem has a 54 degree difference with a 2:30 caliper and 20 degree
forwards dropout. Should be perfectly safe.

Placing the caliper in from of the fork would result in the
reaction force driving the axle into the dropout and eliminating
the ejection force altogether.

Of course true, but although not impossible, undesirable.

Why is that undesirable? I believe it is entirely aesthetics. I see
no technical reason for not doing so. Caliper behind the strut is
much like recessed rim brake anchor nuts (even on the back side of the
fork crown), it looks more "cool".

The 2007 range of "Ben C" mountain bikes will use rear calipers
mounted at 2:30 and slightly forward-opening dropouts. And no
tapering on the forks.

Instead of calculating, I think more would be gained by observing the
reactions on a bicycle by taking out the QR skewer to observe how the
axle moves when someone else pushes the bicycle forward and applies
the disk brake. This does not require a rider to sit on the bicycle,
just pushing it forward will do, the forces being proportional
regardless of load.

Jobst Brandt

On Feb 13, 11:49 am, wrote:
Ben C? writes:
As I said in another thread, if the difference in direction is 45
degrees or better, I don't think you're going to get ejection.
Unless my calculations are still wrong (it's been known...) Ben
Micklem has a 54 degree difference with a 2:30 caliper and 20 degree
forwards dropout. Should be perfectly safe.
Placing the caliper in from of the fork would result in the
reaction force driving the axle into the dropout and eliminating
the ejection force altogether.
Of course true, but although not impossible, undesirable.

Why is that undesirable? I believe it is entirely aesthetics.

But you don't *know* that. So far, this is merely conjecture. Oddly,
others have presented this as fact.

I see
no technical reason for not doing so.

Which means what? That there is no technical reason for doing so?

Another conjecture.

Caliper behind the strut is
much like recessed rim brake anchor nuts (even on the back side of the
fork crown), it looks more "cool".

Opinion based on conjecture.

The 2007 range of "Ben C" mountain bikes will use rear calipers
mounted at 2:30 and slightly forward-opening dropouts. And no
tapering on the forks.

Instead of calculating, I think more would be gained by observing the
reactions on a bicycle by taking out the QR skewer to observe how the
axle moves when someone else pushes the bicycle forward and applies
the disk brake.

And exactly what does this prove, aside from the fact that the
ejection force exists?

Everyone who is involved in this discussion, and for the last few of
these discussions, already agrees that the force exists, and its
approximate magnitude.

What is to be gained, Jobst? How does it change the discussion at
all?

(Anyone want to take bets on how these last two questions will be
studiously avoided?)

E.P.

On 2007-02-13, wrote:
Ben C? writes:

As I said in another thread, if the difference in direction is 45
degrees or better, I don't think you're going to get ejection.
Unless my calculations are still wrong (it's been known...) Ben
Micklem has a 54 degree difference with a 2:30 caliper and 20 degree
forwards dropout. Should be perfectly safe.

Placing the caliper in from of the fork would result in the
reaction force driving the axle into the dropout and eliminating
the ejection force altogether.

Of course true, but although not impossible, undesirable.

Why is that undesirable?

Because it puts the mounting point in tension as explained by jim beam.

Also I am concerned about grit, brake dust etc. coming out of the back
of the caliper being thrown upwards towards the rider's face. With the
caliper behind the fork it's directed towards the road behind the front
wheel.

Ed Pirrero writes:

As I said in another thread, if the difference in direction is 45
degrees or better, I don't think you're going to get ejection.
Unless my calculations are still wrong (it's been known...) Ben
Micklem has a 54 degree difference with a 2:30 caliper and 20
degree forwards dropout. Should be perfectly safe.

Placing the caliper in from of the fork would result in the
reaction force driving the axle into the dropout and eliminating
the ejection force altogether.

Of course true, but although not impossible, undesirable.

Why is that undesirable? I believe it is entirely aesthetics.

But you don't *know* that. So far, this is merely conjecture.
Oddly, others have presented this as fact.

Well, I didn't present it as fact. Now what?

I see no technical reason for not doing so.

Which means what? That there is no technical reason for doing so?

Another conjecture.

Why are you so argumentative. You seem to take my posting as a
personal injury. Instead of "another conjecture" you might propose an
alternative. As you see, what I wrote, I put forth as opinion, not
fact as you seem to assume.

Caliper behind the strut is much like recessed rim brake anchor
nuts (even on the back side of the fork crown), it looks more
"cool".

Opinion based on conjecture.

The 2007 range of "Ben C" mountain bikes will use rear calipers
mounted at 2:30 and slightly forward-opening dropouts. And no
tapering on the forks.

Instead of calculating, I think more would be gained by observing
the reactions on a bicycle by taking out the QR skewer to observe
how the axle moves when someone else pushes the bicycle forward and
applies the disk brake.

And exactly what does this prove, aside from the fact that the
ejection force exists?

Everyone who is involved in this discussion, and for the last few of
these discussions, already agrees that the force exists, and its
approximate magnitude.

What is to be gained, Jobst? How does it change the discussion at
all?

(Anyone want to take bets on how these last two questions will be
studiously avoided?)

How does your "conjecture" response "change the discussion at all"?

The direction of the ejection force and an optimum angle for dropout
slot has not been determined. My suggestion was aimed at resolving
that issue.

Jobst Brandt

Ben C? writes:

As I said in another thread, if the difference in direction is 45
degrees or better, I don't think you're going to get ejection.
Unless my calculations are still wrong (it's been known...) Ben
Micklem has a 54 degree difference with a 2:30 caliper and 20
degree forwards dropout. Should be perfectly safe.

Placing the caliper in from of the fork would result in the
reaction force driving the axle into the dropout and eliminating
the ejection force altogether.

Of course true, but although not impossible, undesirable.

Why is that undesirable?

Because it puts the mounting point in tension as explained by jim beam.

Every bending element is subject to tension. Thee is nothing wrong
with tension or we couldn't build anything right from the Golden Gate
Bridge to the elevator next to the stairs. There is nothing wrong
with tension as we see in spokes that don't fail at mid span where
they are entirely in tension. It is unintended bending that causes
most failures and these fail on their tensile side. Don't give
tension a bad name or we can't play tennis or listen to stringed
instruments.

Also I am concerned about grit, brake dust etc. coming out of the
back of the caliper being thrown upwards towards the rider's face.
With the caliper behind the fork it's directed towards the road
behind the front wheel.

For a particle to fly into your face, it would need to be at least as
large as a grain of coarse sand that flies of the front tire all the
time when on road edge pavement or dirt roads. This is not a hazard.

Jobst Brandt

On Tue, 13 Feb 2007 14:35:54 -0600, Ben C wrote:

Also I am concerned about grit, brake dust etc. coming out of the back
of the caliper being thrown upwards towards the rider's face. With the
caliper behind the fork it's directed towards the road behind the front
wheel.

Only if you're riding backwards surely? What little dust comes out is
going to follow the rotation of the disc and come out forwards.


Mike

On Feb 13, 12:50 pm, wrote:
Ed Pirrero writes:
As I said in another thread, if the difference in direction is 45
degrees or better, I don't think you're going to get ejection.
Unless my calculations are still wrong (it's been known...) Ben
Micklem has a 54 degree difference with a 2:30 caliper and 20
degree forwards dropout. Should be perfectly safe.
Placing the caliper in from of the fork would result in the
reaction force driving the axle into the dropout and eliminating
the ejection force altogether.
Of course true, but although not impossible, undesirable.
Why is that undesirable? I believe it is entirely aesthetics.
But you don't *know* that. So far, this is merely conjecture.
Oddly, others have presented this as fact.

Well, I didn't present it as fact. Now what?

If you're offering technical explanations, why bring your opinion of
positioning into it? What do they have to do with anything?

I see no technical reason for not doing so.
Which means what? That there is no technical reason for doing so?
Another conjecture.

Why are you so argumentative.

Now you're being evasive. Answer the question if you are able, or if
not, say "I don't know." It's really quite simple.

But attacking me is an easy way to avoid the question, right?

[strawman snipped]

Caliper behind the strut is much like recessed rim brake anchor
nuts (even on the back side of the fork crown), it looks more
"cool".
Opinion based on conjecture.
The 2007 range of "Ben C" mountain bikes will use rear calipers
mounted at 2:30 and slightly forward-opening dropouts. And no
tapering on the forks.
Instead of calculating, I think more would be gained by observing
the reactions on a bicycle by taking out the QR skewer to observe
how the axle moves when someone else pushes the bicycle forward and
applies the disk brake.
And exactly what does this prove, aside from the fact that the
ejection force exists?
Everyone who is involved in this discussion, and for the last few of
these discussions, already agrees that the force exists, and its
approximate magnitude.
What is to be gained, Jobst? How does it change the discussion at
all?
(Anyone want to take bets on how these last two questions will be
studiously avoided?)

How does your "conjecture" response "change the discussion at all"?

Another evasion. Not like I predicted it or anything...

The direction of the ejection force and an optimum angle for dropout
slot has not been determined. My suggestion was aimed at resolving
that issue.

"That issue" was resolved long ago. Let me repeat: the direction and
magnitude of the braking forces due to disk brakes is already agreed
upon by most everybody, and certainly everyone participating in this
particular thread.

Bringing it up (again) does nothing to resolve any of the remaining
issues. So why bring it up as a solution? It's an answer to a
question, for this thread at least, no one has asked.

E.P.