"Actually you are the first person to bring up this issue"

"Tim McNamara" wrote in message
...
Not much of a clue, that, since the thread is also cross-posted to
rec.bicycles.tech which has an international audience as a matter of
course (although seems largely American) and alt.mountain-bike which
has an audience of who-knows-what.

People who know and ride the bikes that are being discussed. Unlike you.

tcmedara wrote:

You ****ing hypocritical little weasel.

Easy tiger, it's only "fun and amusement", remember? I already explained
why there was not much point:

1. There's nothing interesting in the CPSC files, we all know that the
manufacturers claim to have never heard of the problem.

2. If there was any evidence of a safety flaw, it would in any case be
prohibited from release by Section 6(b)(5) of the CPSA. Of course if
Tony had realised this he would not have been so mischievous as to say
"You should be able to request all the information they hold on the
subject". Perhaps you should do a little homework before being quite so
free with your insults.

3. The only interest in LaPlante's report is that he is so embarrassed
at its inadequacy that he is not prepared to release it. The whole point
is that there _is_ nothing of interest in it. I've already got the CPSC
letter (both versions) if I want to read a bland whitewash.

4. The fact that that manufacturers are holding up telescopes to their
blind eyes and saying "we see no danger" is clear enough. Did they
report the slippping front wheel (that started this thread) to the CPSC?
Well, we cannot check for sure, but since they did not even ask to see
it, or seem in any way concerned, it should not be too hard to guess the
answer.


James

James Annan wrote:
tcmedara wrote:

You ****ing hypocritical little weasel.

Easy tiger, it's only "fun and amusement", remember? I already
explained why there was not much point:

Watching you twist and turn amidst your own contradictions is quite fun and
amusing. You've explained away alot of things, but that doesn't mean they
just don't exist any more. Why you steadfastly refuse to submit a FOIA
request to support your allegations is the point of the moment.

1. There's nothing interesting in the CPSC files, we all know that the
manufacturers claim to have never heard of the problem.

How do you know what's in the CPSC files if you haven't seen them? You
claimed the CPSC was being "deliberately obstructive", but now claim you
have no interest in what they know or don't know? And why do you really
mean every bike fork manufacturer is lying about the problem. Have you
contacted them all? Or are you making that statement merely because they've
failed to respond to your cries?

2. If there was any evidence of a safety flaw, it would in any case be
prohibited from release by Section 6(b)(5) of the CPSA. Of course if
Tony had realised this he would not have been so mischievous as to say
"You should be able to request all the information they hold on the
subject". Perhaps you should do a little homework before being quite
so free with your insults.

You're the one who doesn't want to do the homework. You should be able to
request all the information they hold. Doesn't mean you'll get it, but
that's a far cry from not asking for it at all. You don't know what you'll
get out of a FOIA request, because you haven't tried it yet. You've given
lots of reasons why you won't try, but then stick to your story line that
the CPSC is stonewalling you. You can't have it both ways in real life.

3. The only interest in LaPlante's report is that he is so embarrassed
at its inadequacy that he is not prepared to release it. The whole
point is that there _is_ nothing of interest in it. I've already got
the CPSC letter (both versions) if I want to read a bland whitewash.

You claim frustration that LaPlante's report wasn't released and now say
there's nothing of interest in it? What makes you so sure that he's
"embarrassed". Maybe he just doesn't feel like dealing with you personally,
knowing that whatever is in his report isn't going to sway your opinion
either way. You easily assert it's a whitewash, but I guess that's easier
than having to actually read it and trying to refute it on it's merits.

4. The fact that that manufacturers are holding up telescopes to their
blind eyes and saying "we see no danger" is clear enough. Did they
report the slippping front wheel (that started this thread) to the
CPSC? Well, we cannot check for sure, but since they did not even ask
to see it, or seem in any way concerned, it should not be too hard to
guess the answer.

I would suggest that there are more manufacturers beyond just those you
cite, but that's just pointless nit-picking really. My guess is that the
issue hasn't made it out of the corporate noise level. Now you can attack
that angle too, but that's much different from them intentionally avoiding
the issue. Failure of the corporations to act as you demand is not prima
facia evidence of conspiricy to cover-up the issue. Get some hard facts
rather than innuendo and you might have a case.

You see James, asserting obstruction on the part of the government and fork
makers and then failing to avail yourself of the tools to prove it really
suggests something other than rational thought is afoot. Using your website
to suggest others contact the CPSC with email but then refusing to attempt
what is ostensibly a more effective approach is --dare I say it?--
hypocritcal. Your lame dodge of not wanting to to be a "dancing bear" is
what earned the "weasel" moniker -- as in "weasel out of a dilemma". The
"****ing" modifier was merely for effect

In reality, I'm quite curious about the real impact of the infamous ejection
force. I wonder if it's really something to worry about, or is it something
that can be mitigated by proper use of the QR (I know your answer James, so
just leave that alone). Anecdotes aside, the question is yet to be
answered. I manage the "gravity/fat ass force" on my seatpost with a QR
despite the inherent design flaw that forces it into the seat tube even with
constant loading and unloading, so I wonder if the same can be done with the
fork. That said, your religious zealotry, artful dodges, and downright
obfuscation unfortunately cloud any meaningful weight you bring to solving
the issue. It keeps the NG interesting though...keep it up!

.......and for $20.00 and your old QRs I'll submit the FOIA request for you.

Tom

"tcmedara" wrote in message news:mXI9c.20940$oH2.4343@lakeread01...
Why you steadfastly refuse to submit a FOIA
request to support your allegations is the point of the moment.

I haven't "steadfastly refused" to do anything. I merely said it would
not achieve anything, and explained why. Maybe I will after all? I
suppose it would be amusing to see what sort of analysis (if any) was
presented to them. Perhaps your encouragement has helped, wouldn't
that be a delicious irony if one of the head-in-the-sand advocates was
the one who actually precipitated the critical step? Don't worry,
there's little chance of that, since this problem will only be solved
when a significant number of cyclists bother to report their slipping
wheels (or worse).

James

James Annan wrote:
"tcmedara" wrote in message
news:mXI9c.20940$oH2.4343@lakeread01...
Why you steadfastly refuse to submit a FOIA
request to support your allegations is the point of the moment.

I haven't "steadfastly refused" to do anything. I merely said it would
not achieve anything, and explained why. Maybe I will after all? I
suppose it would be amusing to see what sort of analysis (if any) was
presented to them. Perhaps your encouragement has helped, wouldn't
that be a delicious irony if one of the head-in-the-sand advocates was
the one who actually precipitated the critical step? Don't worry,
there's little chance of that, since this problem will only be solved
when a significant number of cyclists bother to report their slipping
wheels (or worse).

James

It wouldn't be ironic at all, it would be quite rational. Rather than mere
assertion regarding the CPSC, a FOIA request might actually provide some
real documentation about the role of the CPSC, the actions of fork
manufacturers, and the contents of the infamous LaPlante report. Wouldn't
it be absolutely amazing if it turned out you had it all wrong? Now that
would be irony. And if the FOIA request results in the release of
information that supports your whole construct, I'll be the first to take
credit for the guy that goaded you into it. Now that would be some irony
too.

Call me a "head-in-the-sand advocate" if you choose, but that does nothing
to cover the otherwise obvious holes in your whole theory. No need to
rehash those now, they're all over the thread. I've said it before, I
don't reject the notion, I just don't think it's a certain as you make it
out to be. I'm sure that looks like a "head-in-the-sand" approach to you
and the rest of the true believers, and that's too bad. That precludes you
from seeing the flaws in your own construct and diminishes whatever
credibility you could have brough to bear. This "with us or against us"
approach to a serious question of safety is really counter-productive. It's
absolutely naive to assume you've got the whole thing sewed up tight and
suggest that anyone who might challenge that is either ignorant or
criminally negligent.

My biggest beef with you James isn't with the issue of disks and qr's.
You've gathered a pretty serious pile of evidence. My problem here is that
you (and many others) fail to acknowledge that there's lots of unanswered
questions remaining. You might not care for the answers, but impinging the
motives and intelligence of those who do suggests a faith-based crusade
rather than a rational desire to know the facts.

Tom

Tim McNamara writes:

Name calling doesn't change the facts, BTW. Neither does your
anger nor your emotional reasoning. Everybody that has disk
brakes may just have been hoodwinked by the companies that made
them- those are the people you should be challenging.

Should not the criticism be leveled at the fork manufacturers and
not the brake manufacturers?

IMHO both, since they are equal parts of the system. The brake is
designed by its maker to be mounted behind the fork leg, and the
fork is designed to put it there by its maker. Both are equal
contributors to the problem.

I don't know but do suspect that changing the dropout design might
be the easier solution, and I don't know but do suspect that
changing the location of the brake would be the better solution.

If you consider forks without offset at the dropout end, as they are
commonly made today, where offset is achieved at the fork crown, No
change other than placing the mounting lugs for the disc brake caliper
on the front side is required. I think the same caliper would be
adequate for most brands with the distance between caliper and fork
leg remaining as it is today. This requires a new fork strut anyway.

Changing the dropout is not a reasonable option because the dropout
would need to face upward, which would release the wheel on normal
wheel loads, while reversing loads of rider and brake force, being
opposite, could still cause QR loosening. The dropout should be
loaded in the same direction at all times as it is with rim brakes.

That stress reversals cause unanticipated failures was evident in the
old Shimano short splined hollow BB axles. Riders who descended
standing, right foot forward, had crank loosening and spline failures
as I predicted. We had a similar thread to this one on that issue as
well as one on the progressive ratio Campagnolo Delta brake. Both
products are no longer made for practical and safety reasons.

How long will it take to get the disc caliper ahead of the fork leg?

Jobst Brandt

Tom Sherman wrote:
You could make it quite exciting by locking your brakes and launching
yourself forwards into an upright position to continue on foot.


I have locked both front brakes on my Dragonflyer trike on broom
finished Portland cement concrete surfaces and on unworn (no significant
aggregate polishing has occurred) asphalt cement concrete surfaces. In
neither case did I even come close to flying forward off the bike.

Consider this; if I am able to decelerate at 1-G on my trike, the force
that I will have to resist with my legs is the same magnitude as the
force that I have to exert to stand upright. This obviously is not much
of an issue for a person without a physical handicap.

I was not quibbling with your leg strength. It is now clear to me
that the centre of mass of you and your recumbent is low enough that
you can break the traction with your front wheels (skid) rather than
pivoting on the contact patch as can happen with an upright (endo).

In the case of an endo, bracing against the bars stops you moving
with respect to the bars, but does not prevent the pivoting at the
contact patch. I was wondering (half jokingly) that the same effect
might work on a recumbent and be an interesting circus trick.

--
R.

Richard Brockie "Categorical statements
The tall blond one. always cause trouble."

Richard Brockie writes:

You could make it quite exciting by locking your brakes and launching
yourself forwards into an upright position to continue on foot.

I have locked both front brakes on my Dragonflyer trike on broom
finished Portland cement concrete surfaces and on unworn (no
significant aggregate polishing has occurred) asphalt cement
concrete surfaces. In neither case did I even come close to flying
forward off the bike.

Consider this; if I am able to decelerate at 1-G on my trike, the
force that I will have to resist with my legs is the same magnitude
as the force that I have to exert to stand upright. This obviously
is not much of an issue for a person without a physical handicap.

I was not quibbling with your leg strength. It is now clear to me
that the centre of mass of you and your recumbent is low enough that
you can break the traction with your front wheels (skid) rather than
pivoting on the contact patch as can happen with an upright (endo).

In the case of an endo, bracing against the bars stops you moving
with respect to the bars, but does not prevent the pivoting at the
contact patch. I was wondering (half jokingly) that the same effect
might work on a recumbent and be an interesting circus trick.

I didn't see a picture of this tricycle but short wheelbase recumbent
bicycles, ones where pedal cranks are ahead of the front wheel, do
endo's more easily than a conventional bicycle. Drawing a visual line
from the rider's belly button (rider CG) to the contact patch of the
front wheel shows that the CG is no better positioned than that of a
conventional bicycle and usually worse.

I don't think trikes work well on MTB trails any more than recumbent
bicycles do, the ability to rise off the saddle being absent and with
more than a single track vehicle, most trails are impassable quite
aside from the sudden drops and obstacles that usually abound. In any
case, I have never seen a recumbent on any of the trails in the Santa
Cruz Mountains nor in the Alps in the many years that I have ridden.

Jobst Brandt

wrote:

...
I didn't see a picture of this tricycle but short wheelbase recumbent
bicycles, ones where pedal cranks are ahead of the front wheel, do
endo's more easily than a conventional bicycle. Drawing a visual line
from the rider's belly button (rider CG) to the contact patch of the
front wheel shows that the CG is no better positioned than that of a
conventional bicycle and usually worse....

Picture of my trike.
http://www.ihpva.org/incoming/2002/df1a.jpg .

Mr. Brandt's comments on short wheelbase (SWB) recumbents indicate
outdated and/or incomplete knowledge. The first regular production SWB
recumbent was the Hypercycle. Among other design defects, the Hypercycle
had a very long pedal boom, which meant that the rear wheel would lift
easily when the front brake was applied, and hard braking could well
launch the rider off the front of the bike in a near standing position
and/or put the chainring into the ground.

Better designed (not all, by any means) modern SWB recumbents have a
static weight distribution of approximately 40%/60% front/rear and will
not lift the rear wheel under hard braking. Here is one such common
design that I have ridden extensively (including emergency braking)
without ever lifting the rear wheel.
http://www.ransbikes.com/2004Bikes/Rocket.htm .

Here is a picture of the SWB recumbent I regularly use for longer rides.
http://www.ihpva.org/incoming/2002/sunset/Sunset001.jpg . With the
low seat height and short pedal boom, the angle formed by the ground,
front tire contact patch, and combined bike/rider center of mass is very
small. It would take sudden stoppage of the front wheel (e.g., wedged in
a storm sewer inlet grating) for the rear wheel to lift off of the ground.

--
Tom Sherman - Quad Cities (Illinois Side)

"tcmedara" wrote in message
news:mXI9c.20940$oH2.4343@lakeread01...

In reality, I'm quite curious about the real impact of the infamous
ejection
force. I wonder if it's really something to worry about, or is it
something
that can be mitigated by proper use of the QR (I know your answer James,
so
just leave that alone).

The trouble is that in real life QR's do fail - if we leave aside the why,
it doesn't matter whether it's improper use or vibrating loose as per
James's theories the fact is they do come loose. The ejection force is very
real and seems to have been accepted by most people with an appreciation of
force vectors and / or basic physics. The REAL point is that at present the
system fails catastrophically but had it not been designed negligently and
the calipers positioned in the most sensible place then it would fail safe
in that braking would ensure that the wheel would remain in the dropouts.

It's very easy for the manufacturers to fix on new forks - just put the
mounting tabs on the front of the fork - nothing else is needed. BUT, and
it's a big but, in doing this the manufactuers would effectively be
admitting that there's a *potential* problem and would open the floodgates
to claims and demand for retrospective fixing of the problem. Whilst there
are no large legal cases (and hence costs) relating to this particular
problem then there's no reason for manufacturers to risk changing it. It's
difficult to see how any safety body can address the problem while the
vibrating loose theory remains just that, a theory (albeit one that's been
accepted in court cases in the US albeit unrelated to disc brakes) - the QR
and the lawyers lips should in the vast majority of cases ensure safety,
it's just that one in a million one where thay don't, this will need to be
forced on he manufacturers by cost implications or possibly by consumer
pressure.

Anecdotes aside, the question is yet to be
answered. I manage the "gravity/fat ass force" on my seatpost with a QR
despite the inherent design flaw that forces it into the seat tube even
with
constant loading and unloading, so I wonder if the same can be done with
the
fork.

It's a little less catastrophic if your seat post slips though isn't it,
even if the QR fails comletely - difficult to see how you can end up
paralysed as a result of that.

There's too many people focusing on whether the (wheel) QR can fail if
properly fastened rather than accepting the anecdotal evidence that they do
fail (even if it is as a result of incorrect use) on an alarmingly regular
basis. It doesn't matter why they fail - it's the consequences of it
happening that's the issue, systems should fail safe and we should all be
petitioning the manufacturers to make this simple change to the design of
the forks to ensure that they fail safe rather than failing catastrophically
in order to ensure that bad things don't happen whether or not it can be
proved that they have or haven't already happened.

In answer to your original question the real impact of the infamous ejection
force can almost certainly be mitigated by the proper use of the QR but
mitigation only reduces the chance of something happening - the impact of
the infamous ejection force can be REMOVED completely by a simple design
change. It beggars belief that anyone can actually argue that this would be
a bad thing and that we should not be campaigning for this to happen.

The issue of retrospectively recalling all existing forks is much more
problematical and possibly unecessary, that's something that will be
addressed by the manufacturrs in the light of legal cases and costs.

Russ