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

tcmedara wrote:

LOL. While I think you are an obsessed quasi-religious zealot, that's not
why I'm going to goof on you.....

Dumabass, Frobnitz was *supporting you* !

Yeah, I realised that. I guess humo(u)r doesn't travel well.

He was suggesting that rather
than spam up a bunch of newsgroups where people are probably smart enough to
tighten their QR, you should direct your efforts at the appropriate
regulatory agencies and actually try to do something to fix the "problem".

Actually, although you probably mean well, both you and Frobnitz don't
seem to realise that I _did_ contact the "appropriate regulatory
authorities" last year. They (or, to be precise, the CPSC) said they
needed specific complaints of individual problems, rather than a general
warning of a theoretical design problem.

Of course, when I suggested that some of those riders who had described
their incidents might care to contact the CPSC, I was roundly criticised
for "scaremongering", and as far as I know, not a single rider bothered.
Many of those who understood the problem or had even seen it for
themselves had the touchingly naive belief that the manufacturers would
fix the problem all on their own and it would be overkill to actually
pressure them into doing so. Of course, what they didn't realise is that
the manufacturers have a strong financial incentive to keep the current
designs, since when Joe Bloggs upgrades to disks and finds his QR fork
is not up to the job, he then generally goes out and buys a bolt-through
fork. It's easy enough to see who wins out of this.

Roll on one year, and entirely predictably, the manufacturers are still
pretending the problem doesn't exist. They must be laughing all the way
to the bank.

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.

Your rejection of that course of action suggests that you're more interested
in pursuing your own personal crusade rather than actually solving a
problem -- percieved or otherwise.

Rather than thank him for the suggestion or offer a counterpoint to why it's
not a viable option,

I hope you will now agree that I have offered a counterpoint as to why
it is not a viable option, and I'm sorry for not giving sufficient
explanation earlier. The simple fact is that while MTBers refuse to do
more than grumble on bulletin boards, there is no real complaint to
raise with anyone. I realised several months ago that there was really
nothing more for me to do, but people still keep on emailing me with
their stories, and I thought this latest one was sufficiently
interesting to be worth sharing. Maybe next year there will be another.
Don't hold your breath.

James

"G.T." writes:

"TBF" wrote in message
le.rogers.com...

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.

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.

BenS writes:

On Fri, 19 Mar 2004 13:32:14 -0500, dvt wrote:

Zog The Undeniable wrote:
James Annan wrote:

It's now a year since the QR/disk brake problem hit the
headlines, and I thought some of you might be interested in
hearing how the manufacturers are dealing with it.

I'm pretty sure some manufacturers are now starting to put the
disc on the RH side of the fork.

I might be dense, but I can't see how that would help. I *can* see
that putting the calipers in front of the fork would help, but the
right hand side? What am I missing?

Putting the caliper on the front of the fork would probably lead to
it ripping off it's mounting.

How do you figure? The forces on the mounting bosses on the fork leg
would be the same as they are with the current design.

(Jonesy) writes:

James Annan wrote in message ...

So there you have it. At this rate, by the time next year's
complaint comes in, they will presumably have forgotten this first
one. How convenient for them. Those who thought that it wouldn't do
to kick up a fuss because the poor manufacturers were doing their
best, may wish to re-examine their approach. Or else studiously
ignore this post in the vain hope that the problem will go away.

Assuming, of course, that there actually *is* a problem.

There's no doubt that there is a problem. The only question is how
often it happens.

It'll be nice to see all that wonderful, properly-controlled data
from the laboratory testing.

Think of it like Microsoft Windows: *you* are the testing lab.

When that comes out for public view, then we'll all be able to avoid
drawing conclusions from anecdotal evidence.

It would be nice to have something other than a detailed engineering
analysis quantifying the force and magnitude of the ejection force
created by front disk brakes mounted behind the shock fork leg, paired
with a detailed engineering analysis of how the QR can be unscrewed by
the repeated ejection force resulting from normal use. Ummm, oh yeah,
that's *not* anecdotal evidence. That's objective evidence, which the
anecdotes (including video of a front wheel ejection) serve to
support.

The fact that the brake creates an ejection force at all is evidence
of the design flaw. It's really quite simple. The arguments against
this citing improper use of a QR are just desperate smoke and mirror
attempts to obfuscate.

Westie wrote:
G.T. wrote:
snip

It's much easier to blame the user. That's what you're doing and
that's what the manufacturers are doing. Even though they know the
forces acting to rip the wheel out of the dropout are high.


So why blame people for driving fast?
Surely by now, speed limiters should have been fitted to all vehicles
limiting their speed to 10km/hour to avoid impact injuries.
We all know that the forces acting to squash drivers, passengers and
pedestrians are high.

Studies may have shown that disc brakes apply strong forces to the dropout
but other studies have clearly shown that improperly maintained vehicles
travelling at speed can apply strong forces to human bodies upon impact.
Yet maintain and use a vehicle safely and the odds of your crashing due to
equipment failure are reduced. Why would this not apply to disc brakes?

Despite all the debate I still haven't seen a statistically significant
number reports of injuries resulting from this issue where user error has
been ruled out. Given the numbers of bikes with disc brakes out there there
surely should be several if not dozens of incidents a week if this is a
realistic fault that the average rider should be concerned with.

That's one of the ****tiest analogies I have ever read. Wheels have
ejected even when the user has properly tightened their QR. That should
NEVER happen. Not once. It's not an issue of improper maintenance or
anything analogous to using a bicycle in an unsafe manner.

Greg

The Nelson Paradigm wrote:
G.T. wrote:
| "Twohat" wrote in message
| ...
||
|| "G.T." wrote in message
|| om...
|||
|||
||| It's much easier to blame the user. That's what you're doing and
||| that's what the manufacturers are doing. Even though they know the
||| forces acting to rip the wheel out of the dropout are high.
|||
||| Greg
|||
|||
|| Been braking hard on bumpy bits for over a year now with my Manitou
|| Magnums with Shimano Drybollock discs with no probs.
|| I might believe it if I saw it happen, but I'm not impressed with the
|| quasi-scientific conspiration theorists.
|| Annan has an axe to grind, and I think he is scaremongering
|| un-necessarily IMHO.
||
|
| I hate scaremongering more than anybody (nobody is better at it than
| the US media), but I've read a couple of scary accounts, and believe
| me, I'll be keeping my front skewer very tight. And some day I'll
| switch to a through-axle.
|
| Greg

See, right there is the answer if you happen to feel a skewer is not enough.
Problem solved.



The point is, if there is a problem, that fork manufacturers are selling
disc compatible forks with regular dropouts. If they're selling them there
is no doubt that their safe, eh? I worked at Manitou when their steerers
separated from their crowns, and just after I left their dropouts were
breaking. How long do you think it took them to admit to a problem?

Greg

G.T. wrote:
That's one of the ****tiest analogies I have ever read. Wheels have
ejected even when the user has properly tightened their QR. That
should NEVER happen. Not once. It's not an issue of improper
maintenance or anything analogous to using a bicycle in an unsafe
manner.

I was thinking more of checking the tread depth on vehicles tyres versus
checking the QR is secure.
Regardless of what analogy is used, the issue is more about hearsay more
than solid data at present. I have no doubt that disc brakes create more
torque on the dropouts; but does that really create a problem on anything
but an improperly adjusted quick release?
No-one can say "Yes, it's a problem because we have this many accidents a
year or statistically speaking there will be this many failures".
And if it is a serious problem, what do you propose be done about it?
A design change will fix future occurrences. But what realistically will be
done about existing forks and brake systems?

I'm waiting for more information before I jump on the bandwagon.
--
Westie
(Replace 'invalid' with 'yahoo' when replying.)

"Tim McNamara" wrote in message
...
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'd have thought angling the drop-out so it faces forward would prevent the
axle rotating out if the pads are the pivot point.
I'm still trying to think of any negative implications from doing this as it
seems too easy.
Being cynical a non-mechanical implication would be manufacturers seen to be
fixing a problem they deny exists therefore admitting the potential problem
after the fact and leaving the industry wide open to litigation.
--
Regards,
Pete

in message wsN6c.16296$Cf3.2864@lakeread01, tcmedara
') wrote:

James Annan wrote:
"Frobnitz" wrote in message
...

Have you contacted someone like Watchdog (UK consumer affairs
program, for the non-UK readers on the x-post) to see if they are
interested.

No, I don't think there is any point in that. Firstly, it doesn't
affect me directly, and secondly, they are hardly going to take a
complaint seriously that has only ever been noticed by one rider (and
he didn't even have a crash or anything, it's just that his wheel
won't stay put). Since it's already been cleared by the CPSC, there
is obviously no design problem and I guess I must have made the whole
thing up. It was quite a hassle making all the fake user accounts on
singletrackworld:

http://www.singletrackworld.com/foru...34406&t=933851

and just to make it seem more authentic I forged this review and
hacked into Marin's site:

http://www.marin.co.uk/marin-2004/reviews.php?ID=47

LOL. While I think you are an obsessed quasi-religious zealot, that's
not why I'm going to goof on you.....

*Dumabass,*Frobnitz*was**supporting*you**!

Merkins. They just don't do irony, do they? Something to do with only
having senses of humor, not of humour. There's a lot goes missing with
that second 'u'.

Mind you, of course, most of them wouldn't recognise humour of any sort
if it fell on them in a thunderstorm.

Simon, generally phlegmatic, but occasionally sanguine.

PS Oh, and it was the _philosophers'_ stone.

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

;; Women are from Venus. Men are from Mars. Lusers are from Uranus.

in message ,
') wrote:

Zog The Undeniable wrote:

I'm pretty sure some manufacturers are now starting to put the disc
on
the RH side of the fork. It's certainly an accepted problem.

Or you can just turn the QR around so the lever is on the right side.

Or you could fill your bathtub with brightly coloured machine tools,
whilst intoning in a cod French accent 'this is not a pipe'.

All things are possible.

But I don't see what it has to do with solving the brake ejection
problem.

Simon, rides a Lefty, doesn't have a problem.

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

;; MS Windows: A thirty-two bit extension ... to a sixteen bit
;; patch to an eight bit operating system originally coded for a
;; four bit microprocessor and sold by a two-bit company that
;; can't stand one bit of competition -- anonymous