Carlton Reid on QR safety

Andy H wrote:

Life sucks and **** happens, our (my anyway) pastime is rife with risk. If
the design is inherently flawed why have we not all been maimed by our
disk/qr problems? (As MV would no doubt wish :-).

Who is "MV"?

--
Tom Sherman - Fox River Valley

"They [hominids] ARE acceptable prey, ESPECIALLY mountain bikers."
- M.V.

"We are discussing whether humans as prey are 'natural'. Clearly,
they are, or that mountain lion wouldn't have been trying to eat a
human." - M.V.

"Abnormal would be a mountain lion speaking English." - M.V.

"Mountain lions have always eaten humans, throughout our evolutionary
history." - M.V.

In article ,
"Andy H" wrote:

"David Martin" wrote in message
oups.com...

Werehatrack wrote:
Those of us who have seen your prior postings about the issue of disc
brake ejections are fully aware of your position on the matter. Is it
possible for you to accept the fact that for the majority of the
readers, the evidence thus far published is not persuasive that there
is a serious problem here which is not related to user error?

Why do you claim to speak for the majority of readers, most of whom
have expressed no public opinion on the matter?

..d

Does the fact that the majority of people have expressed no public opinion
(read; interest) speak volumes as to the severity of the problem? Do YOU
know the relevant statistics to say that this is a major problem or design
flaw?

Life is inherently risky and I for one would rather check my qr's before a
ride and have disk brakes than try to do what I do with rim brakes.

I draw inferences from the fact that those who claim there
is no problem refuse to comment upon the force diagram.

--
Michael Press

Johnny Sunset wrote:
Andy H wrote:

Life sucks and **** happens, our (my anyway) pastime is rife with risk. If
the design is inherently flawed why have we not all been maimed by our
disk/qr problems? (As MV would no doubt wish :-).


Who is "MV"?

He who must not be named.

While promoting this new mechanism as "safer" than the existing system, he
also insists that "industry experts say QRs are safe, when used
correctly".

This assertion is backed up with a quote from "industry expert" Bob Burns
(actually Trek's *lawyer*), which is nothing more than a boilerplate
denial dating to a few years ago when the QR/disk issue first surfaced.
=======================
"In 2003, Bob Burns, Trek's US-based General Counsel, told BikeBiz.com:

"Virtually all 'defective quick release' claims that I have seen relate to
an improperly used quick release. Either the consumer has ridden with the QR
open; ridden with the QR closed like a wing nut (rather than closing it over
the cam); or ridden with insufficient tightness to the adjusting nut to
engage the cam."
=======================

Where, exactly, does the quote from Bob Burns say anything whatsoever about
your QR/disk issue? He's addressing only one thing in the quote given- quick
releases. Nothing about disk brakes.

For that matter, not one place in the article is anything said about brakes.
Just quick releases. And the timing and development w/regards Pacific
Bicycles implementing a new quick release design probably has everything to
do with the lawsuit they got hit with (quick releases supposedly failing in
the field on low-end kids bikes) and nothing to do with disk brakes.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com


"James Annan" wrote in message
...
Carlton Reid has a puff piece about a new "Secure QR system" on bikebiz:
http://www.bikebiz.co.uk/daily-news/article.php?id=6427

While promoting this new mechanism as "safer" than the existing system, he
also insists that "industry experts say QRs are safe, when used
correctly".

This assertion is backed up with a quote from "industry expert" Bob Burns
(actually Trek's *lawyer*), which is nothing more than a boilerplate
denial dating to a few years ago when the QR/disk issue first surfaced.

Strangely, alongside this there is no space in his article for these
quotes from people who actually have some relevant engineering and
technical experience:

---
Chris Juden, Technical officer, CTC:
"It's not just scaremongering, but all hangs together and makes perfect
sense. In fact I'm kicking myself for not thinking of it before."

"changes must be made to the way disk brakes and front wheels are attached
to forks"

Jobst Brandt, author, "The Bicycle Wheel":
"The more I see on this the more I find the defense of the status quo
stranger than fiction. Why are writers trying to say that it can't
happen? What motivates writers to claim that disc brakes as currently
offered are not a hazard?

The mechanism has been clearly stated, the forces have been identified in
magnitude and direction, and credible descriptions of failures have been
presented. What's going on here! There is no easter bunny. Believe it!"

John Forester, author, "Effective Cycling":
"All that I can say is gross negligence."

Unnamed Marzocchi Tech Support:
"It is recommended that an 8" rotor is not used on a standard axle fork
because the forces exerted on the wheel can potentially pull the axle out
of the dropouts."

Brant Richards, On-One:
"From the next batch, our rigid forks will have dropouts which are angled
forward at 45degrees or thereabouts.

This is because when I was coming home, and pulling a stoppy outside my
driveway, I kept finding the front wheel shifted in the dropout."

Dave Gray, Surly:
"You are correct. I've noticed the problem on my Karate Monkey fork."

Ben Cooper, Kinetics, describing his experiment:
"Conclusion: From the above, there seems to be an effect from the disc
brake which causes the quick release to loosen."
---


And even more strangely, although he mentions the ongoing Walmart case
concerning children's bikes, and refers repeatedly to user error, he also
didn't find space to mention the recent out of court settlement in which a
manufacturer paid off an (experienced adult) rider who was seriously
injured by a front wheel ejection on a disk+QR fork.


James
--
James Annan
see web pages for email
http://www.ne.jp/asahi/julesandjames/home/
http://julesandjames.blogspot.com/

in message , Richard
') wrote:

Andy H wrote:
Does the fact that the majority of people have expressed no public
opinion (read; interest)

Why do you read that? I have hitherto expressed no public opinion.
I've read James' webpages on the subject and found his hypothesis
interesting and convincing

I've read James' web pages on the subject, and I've listened to other
people (Darth Ben for example) who have empirically verified James'
hypothesis. I ride a lefty off road. I did before I knew about this
problem, it has to be admitted. But if I did now convert back to a
conventional fork, it would have a through axle.

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

;; All in all you're just another hick in the mall
-- Drink C'lloid

Shawn wrote:

Who is "MV"?


He who must not be named.

If you've never encountered worse on Usenet,
you've led a sheltered life.

--
Mike de Van Man

"Andy H" typed

Does the fact that the majority of people have expressed no public opinion
(read; interest) speak volumes as to the severity of the problem? Do YOU
know the relevant statistics to say that this is a major problem or design
flaw?

I have expressed nothing on the subject as I have no relevant knowledge.

This does NOT mean I have no interest; I just try not to post if I have
nothing useful to add.

--
Helen D. Vecht:
Edgware.

Richard typed


Andy H wrote:
Does the fact that the majority of people have expressed no public
opinion
(read; interest)

Why do you read that? I have hitherto expressed no public opinion.
I've read James' webpages on the subject and found his hypothesis
interesting and convincing; I would have liked to investigate the QR
vibrational loosening in more detail, but as I neither sell, use,
maintain, nor have any access to disk brakes or QR axles, I could add
nothing useful to the debate.

YAM & IAY...

--
Helen D. Vecht:
Edgware.

"Andy H" typed



"Richard" wrote in message
...
Snip -
......but as I neither sell, use, maintain, nor have any access to disk
brakes or QR axles, I could add nothing useful to the debate.

R.
Then do just that, you have no potential problems do you? Do you have the
statistics to hand?

Andy H


The problem is not statistical.

The problem is anecdotal.

Many here in the UK will know of a single catastrophic event that might
have been the result of wheel ejection.

A single catastrophe does not a statistic make but it does not mean
there is not a problem.

That IS the problem.

--
Helen D. Vecht:
Edgware.

Mike de Van Man wrote:
Shawn wrote:


Who is "MV"?


He who must not be named.


If you've never encountered worse on Usenet,
you've led a sheltered life.

Sure, but he's still a dick.