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

Jon Senior wrote:

I've included the entire text of your post, untroubled by intruding
comments because it is so funny I felt it should appear again. OK.
You didn't get the joke. That's fine. It's nothing (much) to be
ashamed of. It does seem that everyone else did however.

And frankly, the idea that because someone was serious in the past,
prevents them from being humourous now is preposterous. Can a
stand-up comedian raise a serious point? Could a mortician say
something funny? (I believe it was called "Six-feet Under", although
I sadly missed it!)

Get out more. Get on your bike and burn off some of that bile.

"Have a nice day!"

Jon

Obviously you don't get the point either, Jon. I caught the sarcasm in
Annan's post from the outset. My point was that it was utterly defensive
and misdirected in light of the suggestion to contact an advocacy group. I
concur, people can easily switch between serious discussion and humor.
However I don't often see someone zealously espousing a crusade and then
turn to self-effacing humor on the same topic. Smacks of schizophrenia to
me....

I'd love to go out and ride, but injury prevents that. Bile's all I've got
for the moment (----sarcasm)

Tom

Tim McNamara writes:

I keep hearing about this issue with greater frequency, but I've
been running discs for a few years now and it's only popped out
once in that time. It was my fault on that occasion, I realized
afterwards that I hadn't properly tightend the QR.

What means "properly tightened"?

Just to point out, Jobst, that that's a misattribution. I didn't
write that. So I can't answer your question.

Tim! There were three ahead of that statement, therefore
obviously not from you. I assumed readers understand the notation of
included prior text, common on this medium.

See, that's the point. The brake should be designed so that it
*can't* force the wheel out of the dropouts, even if the QR is
left completely loose. It's a design flaw, an epic design flaw
that will cost some manufacturer a *lot* of money in court some
day. No other current brake design that I'm aware of puts an
ejection force into the wheel in normal operation, but front disk
brakes do.

I wrote the above, though, and thus am responsible for any errors,
misconceptions or rank stupidity it may contain..

Again, it having only two at the time you read it it must have been
from you.

Hold it! Even though this has been discussed at great length here
in wreck.bike, it appears to me that most of the respondents did not
understand that a disc caliper behind the fork causes a wheel
disengaging force, and that repeated braking WILL loosen a QR.

Umm, yes, I do understand that model in concept. Just didn't mention
it in this paragraph as I was focusing on the fundamental problem that
disc brakes create an ejection force in the first place, and not
commenting on the progressive unscrewing of the QR from repeated
application of that ejection force.

Therefore, with the majority of contributors resting in the "James
Annan is all wrong" boat what you just posted gets us back to the
start, a few hundred responses ago.

Hmm. Thought I was agreeing with Annan. Somehow it got construed
that I don't.

You were but the consensus here seems to be opposed to that
preconception and that is what I stated.

Jobst Brandt

wrote:

Do you not believe that current disc brakes cause a disengaging force?
If not, why not? Did you try the test of pushing the bicycle forward
with an open QR and applying the disc brake? If so, did you not
notice that the fork lifts off the axle. You dismiss "line drawings
and vector calculations" although you are surrounded by machines that
are designed by these methods and find them reliable. The test I
offer does not rely on such derivative methods and gets directly to
the issue. How about trying that and apply your own analysis to it.

As I'm sure you agree, it's not a question of belief, it's a question of
physics. I have no doubt the forces act as described. I don't dismiss
them, but I wonder what's missing from the equation. Disk brakes aren't so
new, but where's the empirical data to suggest that this is a problem that
needs solving? Even anecdotally there's not much to go on. Here in AM-B
(yeah, this is cross-posted) there's some serious riders putting some hard
miles on disk brakes. There's always lots of discussion in these QR/Disk
threads, but very little of "Yeah, let me tell you about my experience...."
I'd expect to find it here, if anywhere. A quick look around the internet
suggests all roads return to our friend Mr Annan. Scientific? Not at all,
but suggestive enough to form a hypothesis that there are variables that
aren't being considered. Could it be that the cases that have occurred are
due to failure of substandard QR's? Why hasn't this come out of the
statistical noise level, despite the attention of the cycling public?

To illustrate, my lovely wife subscribes to the CPSC mailing list.
We receive an email nearly ever day listing between 1 and 5
different product recalls. These recalls typically describe what is
often potential flaws and possible dangers -- many of which are damn
near laughable but still result in a recall:

Here's a few examples:
http://tinyurl.com/223qd
http://tinyurl.com/2n2sn

These both seem reasonable hazard warnings. The tire pump has a check
valve failure, something that has ejected pump handles to the ceiling
and the helmet doesn't meet specifications. What is "laughable" about
that.

My point exactly! Okay, laughable may be the wrong term, but the point
should be pretty clear. CPSC will issue warnings about products which
result in chipped teeth and broken fingers, but assiduously avoids tackling
the potentially life-threatening disk-brake phenomenon? Why's that?
Consumers will report minor injuries from a bad pump design, but run away
from the thought of reporting serious trauma caused by their front wheel
flying off? It just doesn't compute. Or do people just dismiss it as bad
luck without wondering why it happened? With all the angst in these NGs, I
can't imagine it's an issue that hasn't been examined by the quintessential
gov't nanny. Or are you going to espouse the manufacturer - gov't
conspiracy theory now, too?

Surf the site and ask yourself if the CPSC is going to overlook the
disk brake risk when bicycle product recalls are issued for injuries
no more severe than a broken finger.

http://tinyurl.com/3yxvb

I think you missed the explanations for this. I concur that without
someone reporting an injury from it, CPSC won't pick it up. The cause
for a wheel disengagement is not obvious and from what we read here,
even difficult to explain how a disc brake can cause a QR to loosen or
for that matter cause an axle to disengage from the fork.

You argue above that the disengagement forces are easily demonstrated, but
now suggest they're not obvious in the empircal world? Which is it? Again,
this smacks of a theoretical problem that, for whatever reason, doesn't
manifest itself in reality. Where are all the injuries? Why *haven't* they
been reported? I'm not disputing the effect, merely suggesting it's not
quite the hazard it's made out to be. Barring outright conspiricy, if the
CPSC will issue this recall: http://tinyurl.com/2gktb where no injuries
were reported, then why would they reject the bigger "problem" ?


Hell, I don't even ride with disks and I think the whole debate is a
crock.

So why do you get so vehement about this issue that you call those who
understand it names and imply they are fabricating the effect?

I'm not so much vehement as someone who enjoys a lively conversation. Any
criticism or name calling is reserved for those who's logical inconsistency
or outright silliness brings what they say into question. In the same vein,
I've noticed a bit of sting in your posts on occasion too, Jobst. I'm no
saint, but this is usenet after all. I'm not suggesting the effect is
fabricated, either. I'm suggesting the danger is more theoretical than
actual. It may just be that riders manage to tighten their QRs and check
them enough to reduce the incidence of *actual* disengagement down into the
noise level. I don't doubt that disengagement *could* happen, I just have
doubts it does happen enough to warrent accusations of cover-up. I don't
feel like rereading the whole thread to find the comments, but I recall the
evil profit motive of the bike makers has been cited as a reason for
inaction on the disk design "crisis."

From what I've read, it seems perfectly reasonable that redesigning the
brake bosses will eliminate the issue. Maybe someday a manufacturer will
retool and do so. However I still wonder if there are other considerations
that preclude such redesign -- other than the conspiricy. If it's so simple,
then why did the industry adopt the current standard (flawed as it may be)?
Likewise, if the theoretical problem proves to be a statistically
significant cycling hazard then the various countries consumer agencies will
hopefully step in. Why hasn't it happened yet?

Every time I get on a bike there's risk. I don't condone unneeded risk and
support avoiding known and potential hazards, but let's worry more about the
actual rather than the potential risks. How about all those crappy
handlebars and seatposts that break even under normal riding conditions.
There's some bad designs out there. How many injuries result from the
crappy design of clipless pedals that are difficult to disengate when you
need to? Where's the uproar there?

Bottom line for me: I'm always skeptical about personal crusades based on
theoretical constructs. Remember the Alar-apple scare years ago? I've no
doubt there was some serious scientic scholarship on the effect of alar on
the human body. The problem, however, was the hysteria that followed was
not warrented by any empirical evidence of it's impact on human health. I
don't reject the notion outright, but I'm skeptical about whether it's a
real problem in search of a solution, or just one more reason among many to
check the QR before riding.

Tom

In article fx07c.17600$Cf3.3839@lakeread01,
"tcmedara" wrote:

wrote:
Tim McNamara writes:


Brake forces and their reactions are apparently to complex to be
discussed among bicyclists who believe anything bought in a bicycle
shop is safely designed.

http://www.ne.jp/asahi/julesandjames...quick_release/


I don't think that at all, but I'm also not going to condemn a product or
indict an entire industry as a result of some line drawings and vector
calculations. Apart from some internet anecdotes and urban legend, I've yet
to see anything remotely resembling evidence of a threat to the public
safety. To illustrate, my lovely wife subscribes to the CPSC mailing list.
We receive an email nearly ever day listing between 1 and 5 different
product recalls. These recalls typically describe what is often potential
flaws and possible dangers -- many of which are damn near laughable but
still result in a recall:

Here's a few examples:
http://tinyurl.com/223qd
http://tinyurl.com/2n2sn

Surf the site and ask yourself if the CPSC is going to overlook the disk
brake risk when bicycle product recalls are issued for injuries no more
severe than a broken finger. http://tinyurl.com/3yxvb

Well, actually these sound like really damn' obvious problems! To those
who didn't surf the links, here's what's described:

Item 1: a bike pump that under certain circumstances will fire the pump
handle upwards under pressure. In one case, hard enough to chip a tooth.
That's pretty bad!

Item 2: a helmet that failed the CPSC-standard impact test. That seems
to strike at the heart of the purpose of a helmet.

Item 3: "The stems on these bicycles can loosen during use." I think we
can agree that's a really big deal, eh?

I'm the last person to believe the government (US or anywhere else) ought to
be the ever protective nanny, and I'm not suggesting that if the CPSC isn't
interested than there's no problem. I'm merely illustrating that the idea
of a huge conspiricy to cover up the problems, and a tremendous lack of hard
evidence suggests the "problem" exists in the realm of the theoretical only.

The problem is that the practical evidence of failures is buried in the
fuzz of other quick-release failure modes. We know that people forget to
tighten QRs on their own fairly often, so whenever a report is heard of
a wheel ejecting, the natural response is "oh, they probably didn't
close the QR properly before they started riding."

And since there's no way to prove after the fact that you really are the
most obsessive rider in the world about QR security, there's an obvious
suggestion as to how these accidents do get buried in the statistical
fuzz.

Ironically, we may see fewer reports of spontaneous QR failure as time
goes on, because the industry trend is towards non-dropout axle
retainers (QR20 or through-axle designs) on the types of bikes most
likely to have disc brakes. This is being done to make the front end
stiffer and stronger for unrelated reasons, but by a happy accident also
cures this problem.

--
Ryan Cousineau, http://www.sfu.ca/~rcousine/wiredcola/
President, Fabrizio Mazzoleni Fan Club

"James Annan" wrote in message
...
snip

........who prefer to **** and moan on usenet than actually _do_ anything.

What, like ride??

James Annan wrote:
tcmedara wrote:


I don't mean well at all. I responded 'cause I find humor in
pointing out logical inconsistency. I didn't "realise" you'd
contact anyone because you rejected the notion as not worthwhile.
I'm pretty intelligent, but not clairvoyent. I could have realized
it had you bothered to mention it.

If you had glanced at the website you would have seen. In fact, anyone
coming new to the debate who thinks they have some startling insight
should probably read it. My dealings with the CPSC are detailed at

http://www.ne.jp/asahi/julesandjames...ease/cpsc.html

and you might learn something from the related pages too.

If you want to make a point, then make the point. Don't force me to surf
your silly site to divine what you may or may not have done. However, I
have now looked at the web site, full of assertion, anecdote, and
conspiracy theories. A good read, though

As for J DeMarco at the CPSC, well he commissioned Mark LaPlant of
Cannondale to report on the issue, and surprisingly enough the
turkey didn't vote for Christmas. In fact he produced a bull****
whitewash which he refuses to publish. But since all the
manufacturers can (apparently truthfully) claim that no rider has
ever reported any incident, there really is little more that the
CPSC can (or probably should) do.


Again, not the "truth" you espouse so therefore it's a "whitewash".
Next you're going to tell us the CIA is behind it all right? Ya
know, if you could document actual circumstances (rather than
internet anecdotes and gossip), than you could prove the point to
the apparently intransigent CPSC.

I suggest you read the letters I've posted on that page, and try to
work out a plausible explanation for his behaviour.

The letters don't mean much. I could search out thousands of posts in these
NGs alone where riders will proclaim years of use with nary a problem. Do
those matter? How's this for an explanation: He investigated the issue,
found nothing to worry about, and has written you off. Maybe you strike him
as one of probably millions of consumers with an axe to grind on the hazards
of "product x". Having covered the issue already, he's probably not
interested in dealing with it anymore. Maybe it was cutting into his biking
time.

A quick summary:

I emailed DeMarco several times in August and September, and was
repeatedly told that a letter was on its way, or had even been sent.
Eventually I got a bland Word document as an email attachment.

Bland? What did you expect from a buearucrat?

In mid October, I received the official letter which was significantly
different. Although dated 2 Sept, it was only posted on the 15th
October, a couple of days _after_ the ASTM meeting to which it refers.

DeMarco has not replied to any of my emails since that date. Mark
Laplant refuses to publish his report which was presented at the
"open" ASTM meeting.

I'd be interested to see your emails to him. I'm wondering if that might
explain how you ended up in his killfile. And while Laplant "refuses" to
publish his report, can't you at least give us a synopsis of what he
presented? You call it a whitewash, but offer no content. Has anyone
actually requested that he publish the report? Are there any policies that
require him to do so, either by the CSPSC or the ASTM. If it was done at
the request of the CPSC it should be available via a FOIA request. Have you
tried that? Or does self-righteous indignation render such details
irrelevent?


Ask them yourselves if you don't believe me. Oh, I forgot, you're one
of those who prefer to **** and moan on usenet than actually _do_
anything.

I'm not "****ing an moaning", I'm chuckling. Check the thread dude....yours
is the original post, and it's pretty much a **** and moan from the outset.
I'm merely participating in a discussion on usenet. I do it for fun and
amusement, not to evangalize. I'm not the one who's advocating an issue,
you are. I'll do something when it needs doing. Are you upset because I've
failed to heed your call to arms? What would you have me do? Let me give
you a hint: If you're looking to _do_ something, or prod others to do it,
then usenet ain't the place to be. People come here to debate, chat, share,
discuss, joke, and argue -- not to "do" anything.

See my response to Jobst Brandt elsewhere in this thread. I'm not doubting
the physics or the mechanism you describe, I'm just doubting that it's quite
the problem you espouse. Is a potential problem that fails to materialize
really a problem at all? Like I asked Jobst: Is this really a problem in
the empirical world, or just another reason to check your QR before you
ride? I know *your* answer, but it seems it's not so certain in the minds
of many others.

Tom

Ryan Cousineau wrote:
In article fx07c.17600$Cf3.3839@lakeread01,
"tcmedara" wrote:

Well, actually these sound like really damn' obvious problems! To
those who didn't surf the links, here's what's described:

Item 1: a bike pump that under certain circumstances will fire the
pump handle upwards under pressure. In one case, hard enough to chip
a tooth. That's pretty bad!

Item 2: a helmet that failed the CPSC-standard impact test. That seems
to strike at the heart of the purpose of a helmet.

Item 3: "The stems on these bicycles can loosen during use." I think
we can agree that's a really big deal, eh?

My point was that the CPSC would issue recalls for bicycle components, even
based on minor or even potential injury. I'm merely asking the question of
why, in light of the propensity for the CPSC to protect us from relatively
minor risks, would they dismiss the disk/qr issue so readily?

The problem is that the practical evidence of failures is buried in
the fuzz of other quick-release failure modes. We know that people
forget to tighten QRs on their own fairly often, so whenever a report
is heard of a wheel ejecting, the natural response is "oh, they
probably didn't close the QR properly before they started riding."

And since there's no way to prove after the fact that you really are
the most obsessive rider in the world about QR security, there's an
obvious suggestion as to how these accidents do get buried in the
statistical fuzz.

So you're saying there's no way to know if the disk/qr issue is really a
risk in light of all the other qr related hazards out there. This makes a
great argument to redesign the quick release, regardless of the type of
braking system used. It also points to what I've been saying all along --
There's really no way to determine if the potential disk brake/qr problem
actually translates into real problems on the trail. Assuming it's the
disk design, even as a prudent measure, could actually result in failure to
detect the likely cause of wheel releases. Maybe there's just a bunch of
crappy QRs out there that shouldn't be on any bike. If it's buried in the
statistical fuzz, then there's no way to draw conclusions.

Ironically, we may see fewer reports of spontaneous QR failure as time
goes on, because the industry trend is towards non-dropout axle
retainers (QR20 or through-axle designs) on the types of bikes most
likely to have disc brakes. This is being done to make the front end
stiffer and stronger for unrelated reasons, but by a happy accident
also cures this problem.

I gotta agree there. Take the guess work right out of it and mitigate lots
of risk from a variety of real and potential sources. I do like that QR
though....

Tom

tcmedara wrote:

Where are all the injuries?

Are you familiar with Russell Pinder's accident?

~PB

tcmedara wrote:

My point was that the CPSC would issue recalls for bicycle components, even
based on minor or even potential injury. I'm merely asking the question of
why, in light of the propensity for the CPSC to protect us from relatively
minor risks, would they dismiss the disk/qr issue so readily?

Because the manufacturers have insisted that it has never happened to
any users, and given an absence of riders prepared to contact them to
say otherwise (even though they are happy to write about it on usenet
and bulletin boards) there is no reason for the CPSC to doubt that. In
their eyes, it remains a hypothetical problem which never happens in
real life. Were it not for all the people who have described their
symptoms of loosening QRs - and several who have lost the front wheel in
situations where operator error is an implausible explanation - they
could even be right. But I didn't just sit down with a pencil and pad of
paper one day and invent this whole thing up out of my imagination, the
conclusions were drawn from an analysis of dozens of consistent and
convincing descriptions of the same phenomona. It is not a coincidence
that the explanation finally came to me about a fortnight after the news
of Russ' crash.

James

tcmedara wrote:

The letters don't mean much.

So why do you think he sent two versions, one which did not mention the
ASTM meeting but arrived in plenty of time, and one which did mention
the meeting but was only posted after it had happened?

On 25 August he said:

"Letter was sent to Japan last week. I will try to e-mail you a copy."

On 2 Sept (after another prompt) he sent the "unofficial copy" by email.
He did not reply to my question as to whether this wording was the same
as the official version.

On 15 OCTOBER he posted the official response. It was dated 2 Sept but
differed significantly from the "unofficial copy" that he emailed on
that very day.

Now it's your turn to think up a reasonable explanation for all this.
I'm out of ideas.

And while Laplant "refuses" to
publish his report, can't you at least give us a synopsis of what he
presented?

Why don't you ask him, or DeMarco. They might reply to you.

You call it a whitewash, but offer no content. Has anyone
actually requested that he publish the report?

Yes, myself and a journalist.

Are there any policies that
require him to do so, either by the CSPSC or the ASTM. If it was done at
the request of the CPSC it should be available via a FOIA request. Have you
tried that? Or does self-righteous indignation render such details
irrelevent?

I don't know what legal right I might have (not being a US citizen). I
have asked but as I mentioned earlier, DeMarco has not replied to my emails.

He did, apparently, insist to the same journalist that I was told of the
ASTM meeting on the 2nd September, which seems a bizarre lie given the
postmarked envelope, letter and Word document which I still have in my
inbox. I think I have some justification for my paranoid conspiracy thories.

Let me give
you a hint: If you're looking to _do_ something, or prod others to do it,
then usenet ain't the place to be. People come here to debate, chat, share,
discuss, joke, and argue -- not to "do" anything.

I'm in Japan, usenet (and other BBs etc) is pretty much all I've got for
getting things done. This problem was solved through input from others
on (especially) rbt and singletrackworld. Without the internet, it would
never had seen the light of day. I realise _you_ are just here to
"discuss, joke and argue" but the internet (with usenet being one part)
is a seriously powerful research tool for those who wish to use it as such.

James