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



A

amakyonin

Guest
I once partially ejected the rear wheel on my road bike. I had only
had the bike for a few days and knew that I should check the skewers
for proper tightness but it always slipped my mind whenever I took it
out for a ride. As luck would have it I ended up bring cut off by a
poor driver and I had to make a panic stop from about 20mph that
lifted my rear wheel high, almost doing an endo. I brought on the rear
brake hard after the rear wheel had lifted and that provided the
opportunity for the rear wheel to pop out of the drive side dropout. I
then slammed back down on the rear wheel before I could unclip and
demount the saddle to land on my foot. This bent up the skewer and put
the wheel out or true but it was still rideable with the brake left
open. Lesson learned: always adjust the skewers on a new bike, even
one from a good LBS.
 
A

A Muzi

Guest
> Tim McNamara wrote:
>> In article <[email protected]>,
>> jim beam <[email protected]> wrote:
>>> Tim McNamara wrote:
>>>> In article <[email protected]>,
>>>> jim beam <[email protected]> wrote:

-disc Q/R wheels eject on braking-
-does not / does too-
-repeat-

jim beam wrote:
>i mean it seriously
> - globally, how many ejections have there been? aren't they all from
> custom forks without lawyer lips? and how can we definitely disprove
> user error?


That's the compelling argument for me..

Now that millions of XMart bikes equipped with disc brakes, sloppy
assembly, inattentive owners and CPSC quick releases have been on the
road a few years, we'd expect more than a couple of anecdotal incidents
if the situation were truly dire.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
 
W

Werehatrack

Guest
On Wed, 07 Feb 2007 00:49:23 -0700, [email protected] may have
said:

>On Wed, 07 Feb 2007 03:27:21 GMT, Martin Dann
><[email protected]> wrote:
>
>>Mike Causer wrote:
>>> On Tue, 06 Feb 2007 18:40:59 +0000, wafflycat wrote:
>>>
>>>> http://www.bikebiz.com/Wheel-ejection-theory-goes-legal
>>>
>>> Ummmmm. So who's going to announce this on r.b.t?
>>>
>>>
>>> Mike

>
>Dear Mike, Martin, & WC,
>
>Should we expect to see the theory confirmed by reproduction? Or has
>that already been done?


This is just blatant speculation, but I look for the eventual finding
to be that the design has a problem which can result in wheel ejection
which would not occur with a rim-brake bike, due to a marginal
operational condition that poses a special hazard which is easily
overlooked and can go unrecognized even with casual inspection due to
a lack of other symptoms.

Mitigating in favor of the defense is the relatively small number of
recorded incidents; it may be difficult to convince a court that the
problem is as fraught with peril as has been claimed by some, when the
vast majority of bikes under discussion do not show any signs of the
failure. The manufacturers might actually be better off if they can
demonstrate a repeatable and applicable failure mode to explain the
incident under review, particularly if the failure requires a special
set of circumstances before it will actually manifest itself. This
would, at least, allow a reasonable quantification of the risk for the
average rider, which would in turn permit the legal types to assess
what the liability should be.

Of course, nearly any such finding could cause some relatively massive
disruptions in the manufacturing and distribution areas, with the
possibility that some distributors for foreign manufacturers might be
bankrupted if large numbers of forks end up having to be replaced.
(This would not be the first time that such a result had been seen.)
What I more strongly suspect is that a whole lot of QR axles could end
up recalled for replacement by solids, or perhaps an anti-ejection
clip of some sort may be introduced to band-aid over the problem. In
the main, I doubt that the final result will be as drastic as the
worst-case scenarios paint it, for a variety of practical reasons.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.
 
W

Werehatrack

Guest
On Wed, 07 Feb 2007 07:32:17 +0000, Tony Raven <[email protected]>
may have said:

> It is a good thing that it is
>being taken to Court. It may take some time but the Court is a good
>forum to have the merits on both sides debated and reach a conclusion -
>and I am prepared to admit my view on the theory could be wrong. As we
>have seen the UK Courts are rather good at this if you look at things
>like the bicycle helmet cases and many other nutty issues. Much better
>than they are at setting appropriate sentencing for motorised killers.


Your courts are at variance from those in the US in many instances, I
believe. Here, it is not uncommon for the result of a civil suit to
be dramatically at variance with the law and/or the facts, due
entirely to the effects of the "who has the better lawyer" rule. As
for sentencing in criminal cases, the lack of consistency, relevance,
and attention to actual justice is at least as remarkable here as
there, if in different directions at times.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.
 
E

Ed Pirrero

Guest
On Feb 7, 7:57 pm, A Muzi <[email protected]> wrote:
> > Tim McNamara wrote:
> >> In article <[email protected]>,
> >> jim beam <[email protected]> wrote:
> >>> Tim McNamara wrote:
> >>>> In article <[email protected]>,
> >>>> jim beam <[email protected]> wrote:

>
> -disc Q/R wheels eject on braking-
> -does not / does too-
> -repeat-
>
> jim beam wrote:
> >i mean it seriously
> > - globally, how many ejections have there been? aren't they all from
> > custom forks without lawyer lips? and how can we definitely disprove
> > user error?

>
> That's the compelling argument for me..
>
> Now that millions of XMart bikes equipped with disc brakes, sloppy
> assembly, inattentive owners and CPSC quick releases have been on the
> road a few years, we'd expect more than a couple of anecdotal incidents
> if the situation were truly dire.


Ding!

We have a winner. Give the man a cigar.

E.P.
 
On Wed, 07 Feb 2007 22:17:16 -0600, Werehatrack
<[email protected]> wrote:

>On Wed, 07 Feb 2007 00:49:23 -0700, [email protected] may have
>said:
>
>>On Wed, 07 Feb 2007 03:27:21 GMT, Martin Dann
>><[email protected]> wrote:
>>
>>>Mike Causer wrote:
>>>> On Tue, 06 Feb 2007 18:40:59 +0000, wafflycat wrote:
>>>>
>>>>> http://www.bikebiz.com/Wheel-ejection-theory-goes-legal
>>>>
>>>> Ummmmm. So who's going to announce this on r.b.t?
>>>>
>>>>
>>>> Mike

>>
>>Dear Mike, Martin, & WC,
>>
>>Should we expect to see the theory confirmed by reproduction? Or has
>>that already been done?

>
>This is just blatant speculation, but . . .


[snip]

Dear Werehatrack,

That's why I'm curious if there's been any actual testing.

:)

Cheers,

Carl Fogel
 
T

Tony Raven

Guest
Werehatrack wrote on 08/02/2007 04:22 +0100:
> On Wed, 07 Feb 2007 07:32:17 +0000, Tony Raven <[email protected]>
> may have said:
>
>> It is a good thing that it is
>> being taken to Court. It may take some time but the Court is a good
>> forum to have the merits on both sides debated and reach a conclusion -
>> and I am prepared to admit my view on the theory could be wrong. As we
>> have seen the UK Courts are rather good at this if you look at things
>> like the bicycle helmet cases and many other nutty issues. Much better
>> than they are at setting appropriate sentencing for motorised killers.

>
> Your courts are at variance from those in the US in many instances, I
> believe. Here, it is not uncommon for the result of a civil suit to
> be dramatically at variance with the law and/or the facts, due
> entirely to the effects of the "who has the better lawyer" rule.
>


That's because we use an expert judge and you use a lay jury to hear the
case. We reserve the lay jury for the appeal to the House of Lords ;-)

My own personal view is that if it were a real problem we would have
seen many more instances by now with the growing prevelance of disc
brakes on low end bikes. What we have seen is people crash and find
their wheels detached from the bike. But I have seen that happen in
road bike crashes with rim brakes so separation of the wheel is, of
itself, not proof it was ejected by disc brake forces.


--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy
 

dabac

Well-Known Member
Sep 16, 2003
2,298
288
83
52
A Muzi said:
...
Now that millions of XMart bikes equipped with disc brakes, sloppy
assembly, inattentive owners and CPSC quick releases have been on the
road a few years, we'd expect more than a couple of anecdotal incidents
if the situation were truly dire.

You have a point, but bikes sold doesn't quite equal bikes used. How many of the riders using low-end bikes do you think have the skills to brake HARD w/o simply endo'ing? I'd say most casual riders are too fearful of locking up the front wheel or going over the bars to ever put the front brake to the test. Since it appears to be a rare phenomenon (whatever it is) maybe cheap bikes, poorly maintained but ridden hard is the provocation required to see any numbers of this event.
 

dabac

Well-Known Member
Sep 16, 2003
2,298
288
83
52
Tony Raven said:
...What we have seen is people crash and find
their wheels detached from the bike. But I have seen that happen in
road bike crashes with rim brakes so separation of the wheel is, of
itself, not proof it was ejected by disc brake forces.

I've been thinking about that too. It's no wonder if a rider's recollection of the chain of event prior/during a bad fall is a bit muddled, so how to isolate wheel ejection due to brake interaction from other possible causes? Is there some common denominator in falls where rim braked bikes have lost their front wheels?
 
J

jim beam

Guest
dabac wrote:
> Tony Raven Wrote:
>> ...What we have seen is people crash and find
>> their wheels detached from the bike. But I have seen that happen in
>> road bike crashes with rim brakes so separation of the wheel is, of
>> itself, not proof it was ejected by disc brake forces.

>
> I've been thinking about that too. It's no wonder if a rider's
> recollection of the chain of event prior/during a bad fall is a bit
> muddled, so how to isolate wheel ejection due to brake interaction from
> other possible causes? Is there some common denominator in falls where
> rim braked bikes have lost their front wheels?
>

yes - invariably the wheel wasn't tightened properly. in some of the
open cam designs for instance, the cup washer that sits under the cam is
not always seated right - if that slips into correct position, suddenly
the skewer is loose. and i know that because i've made that mistake on
a road bike. other times, you just forget [- old timers disease?].

if you read the shimano instructions for their skewers, they say how to
tighten, /and/ they instruct you to bang on the top of wheel to try
ejecting it. it may not catch a mispositioned skewer cup, but it'll
catch the old timers mistake.
 
J

jim beam

Guest
dabac wrote:
> A Muzi Wrote:
>> ...
>> Now that millions of XMart bikes equipped with disc brakes, sloppy
>> assembly, inattentive owners and CPSC quick releases have been on the
>> road a few years, we'd expect more than a couple of anecdotal
>> incidents
>> if the situation were truly dire.

>
> You have a point, but bikes sold doesn't quite equal bikes used. How
> many of the riders using low-end bikes do you think have the skills to
> brake HARD w/o simply endo'ing? I'd say most casual riders are too
> fearful of locking up the front wheel or going over the bars to ever
> put the front brake to the test. Since it appears to be a rare
> phenomenon (whatever it is) maybe cheap bikes, poorly maintained but
> ridden hard is the provocation required to see any numbers of this
> event.
>
>

the problem with cheap bikes is people not knowing how to use skewers at
all. seriously, "wing nut" tightening is frighteningly common.
 
On Feb 8, 12:18 am, [email protected] wrote:
>
>
> That's why I'm curious if there's been any actual testing.


There are two aspects to this problem. The first is the existence of
a force in a direction that tends to eject the axle. The second is
the response of the quick release that allows the QR to fail to retain
the axle.

I assume there's no argument about the first part. It's really pretty
trivial. So the question becomes, do tests show the QR can loosen
under realistic conditions?

Yes, tests have shown this, although they have not been as lab-
oriented as you typically seem to prefer. See http://www.ne.jp/asahi/
julesandjames/home/disk_and_quick_release/#support

ISTM the problem pops up almost exclusively with hard braking on very
rough bumpy descents, especially long descents. If the resulting
hammering goes on long enough and hard enough, it seems the QR
adjustment can wiggle loose and allow ejection.

Any lab test would have to duplicate this condition. Until then, the
tests described at the above link sound pretty conclusive to me.

And BTW, I agree that the problem occurs to only a tiny percentage of
riders. I think it's _very_ unlikely to occur to the 99% of mountain
bike purchasers who putter along on city streets and mild off-road
terrain. (Face it, most folks buy a mountain bike, then do the kind
of riding for which a Raleigh 3-speed would be equally appropriate.)

But when it happens to someone riding the bike "as advertised," I
think the manufacturers bear responsibility. It's a faulty design.

- Frank Krygowski
 
On 8 Feb 2007 09:11:47 -0800, [email protected] wrote:

>On Feb 8, 12:18 am, [email protected] wrote:
>>
>>
>> That's why I'm curious if there's been any actual testing.

>
>There are two aspects to this problem. The first is the existence of
>a force in a direction that tends to eject the axle. The second is
>the response of the quick release that allows the QR to fail to retain
>the axle.
>
>I assume there's no argument about the first part. It's really pretty
>trivial. So the question becomes, do tests show the QR can loosen
>under realistic conditions?
>
>Yes, tests have shown this, although they have not been as lab-
>oriented as you typically seem to prefer. See http://www.ne.jp/asahi/
>julesandjames/home/disk_and_quick_release/#support
>
>ISTM the problem pops up almost exclusively with hard braking on very
>rough bumpy descents, especially long descents. If the resulting
>hammering goes on long enough and hard enough, it seems the QR
>adjustment can wiggle loose and allow ejection.
>
>Any lab test would have to duplicate this condition. Until then, the
>tests described at the above link sound pretty conclusive to me.
>
>And BTW, I agree that the problem occurs to only a tiny percentage of
>riders. I think it's _very_ unlikely to occur to the 99% of mountain
>bike purchasers who putter along on city streets and mild off-road
>terrain. (Face it, most folks buy a mountain bike, then do the kind
>of riding for which a Raleigh 3-speed would be equally appropriate.)
>
>But when it happens to someone riding the bike "as advertised," I
>think the manufacturers bear responsibility. It's a faulty design.
>
>- Frank Krygowski


Dear Frank,

Sorry, I mean tests that show ejection during disk-brake braking.

That page (http://tinyurl.com/2vbhsf) seems to be mostly anecdotes,
plus a rather misleading reference to a rather iffy experiment about
possible skewer loosening:

http://kinetics.org.uk/html/experiment.html

The experiemnt was a bit iffy: a "torque meter" is said to be "less
accurate" than the unblinded experimenter's opinion of when the QR
began to "bite"--could be true, but it seems implausible at first
glance.

The experiment wasn't measuring a normally tightened QR: "So this was
looser than I previously had it, but still 'hand tight'."

And the experiment's conclusion is hardly what the referring page
suggested: "Since this disc bike was used with the same skewer for
over a year with no adjustment, it is apparent that this effect only
occurs if the skewer is not tight enough. There is a certain critical
limit - below this limit, the skewer can loosen - above this limit, it
won’t."

Cheers,

Carl Fogel
 
S

Skippy

Guest
"jim beam" <[email protected]> wrote in message
news:[email protected]
> dabac wrote:
>> A Muzi Wrote:
>>> ...
>>> Now that millions of XMart bikes equipped with disc brakes, sloppy
>>> assembly, inattentive owners and CPSC quick releases have been on the
>>> road a few years, we'd expect more than a couple of anecdotal
>>> incidents
>>> if the situation were truly dire.

>>
>> You have a point, but bikes sold doesn't quite equal bikes used. How
>> many of the riders using low-end bikes do you think have the skills to
>> brake HARD w/o simply endo'ing? I'd say most casual riders are too
>> fearful of locking up the front wheel or going over the bars to ever
>> put the front brake to the test. Since it appears to be a rare
>> phenomenon (whatever it is) maybe cheap bikes, poorly maintained but
>> ridden hard is the provocation required to see any numbers of this
>> event.
>>
>>

> the problem with cheap bikes is people not knowing how to use skewers at
> all. seriously, "wing nut" tightening is frighteningly common.


Yup

I was asked to show 2 customers on Saturday how to tighen up the QRs. Both
had been 'wing-nutted' up to bring the bike in.

And of course, it's always the front...

Skippy
E&OE
 
E

Ed Pirrero

Guest
On Feb 7, 8:25 pm, Michael Press <[email protected]> wrote:
>
> Over the course of a ride
> successive brake applications and simultaneous trail
> impacts will loosen the qr nut, reducing the retaining
> force.


"Will"? That's a strong (unproven) statement.

> Many people have reported this loosening.


Or, reported that they hadn't tightened it up properly to begin with.

And, oddly, these stories of "spontaneous loosening" seem to happen
almost exclusively in the U.K.

Maybe our English kin have weak hands?

E.P.
 
G

Gary Young

Guest
On Wed, 07 Feb 2007 21:57:16 -0600, A Muzi wrote:

>> Tim McNamara wrote:
>>> In article <[email protected]>,
>>> jim beam <[email protected]> wrote:
>>>> Tim McNamara wrote:
>>>>> In article <[email protected]>,
>>>>> jim beam <[email protected]> wrote:

> -disc Q/R wheels eject on braking-
> -does not / does too-
> -repeat-
>
> jim beam wrote:
>>i mean it seriously
>> - globally, how many ejections have there been? aren't they all from
>> custom forks without lawyer lips? and how can we definitely disprove
>> user error?

>
> That's the compelling argument for me..
>
> Now that millions of XMart bikes equipped with disc brakes, sloppy
> assembly, inattentive owners and CPSC quick releases have been on the
> road a few years, we'd expect more than a couple of anecdotal incidents
> if the situation were truly dire.


Years ago I was prescribed a medication that had a rather bothersome side
effect. When I told my doctor, he looked in the Physician's Desk
Reference (PDR), and told me that that side effect had not previously been
reported. He took me off the medication, but strongly hinted that it was
all in my head. Years later I read an article about the medication that
mentioned that very side effect.

The list of side effects in the PDR was probably drawn up during the
manufacturer's clinical trials, which may not have caught all side effects
because the trials are fairly short-term (among other possible reasons).

What happens when someone complains about a side effect not on the PDR
list? That list tends to be used as a filter to distinguish valid versus
invalid complaints, leading to the purportedly invalid complaints being
ignored. That's particularly true where there an alternative explanation
ready at hand -- "It's all in his head," in my case. "He must not have
tightened the skewer properly," in the case at hand.

Actually, it's worse in the case at hand -- this problem could
occur with some frequency and yet not be reported at all because most
riders probably say to themselves, "I must not have tightened the skewer
properly."

My doctor probably would have caught on when the second person walked in
with my side effect, but if the incidence is fairly low, that could take a
long time.

This kind of thing happens all the time. I think it took years for people
to realize that the Ford/Firestone problem was the common thread among
several accidents.

You only have to look at the rbt threads on this subject to see the filter
in use -- just look at how many people dismiss the reports as being the
product of misuse of skewers without knowing anything about the facts of
individual cases.

Finally, I think this is a significant problem even if it occurs rarely --
first of all because it can cause very serious injury and secondly because
it's a trivial matter to correct (trivial at least with respect to future
production of forks).

If fork manufacturers continue to put the brake on the back of the fork,
knowing that producing a fork with forward mounting would cost
little more to produce and might save even a few lives, then that's just
criminal in my book and I expect juries would agree. At the very
least, they should tell their customers about the problem.
 
P

Patrick Lamb

Guest
On Thu, 08 Feb 2007 07:57:55 +0000, Tony Raven <jun[email protected]>
wrote:
>Werehatrack wrote on 08/02/2007 04:22 +0100:
>> Your courts are at variance from those in the US in many instances, I
>> believe. Here, it is not uncommon for the result of a civil suit to
>> be dramatically at variance with the law and/or the facts, due
>> entirely to the effects of the "who has the better lawyer" rule.
>>

>
>That's because we use an expert judge and you use a lay jury to hear the
>case. We reserve the lay jury for the appeal to the House of Lords ;-)


I was going to note that an appeal to expert judges might be
considered preferable, until I remembered the political hacks that
inhabit our (US) Supreme Court.

Pat

Email address works as is.
 
A

A Muzi

Guest
>> Werehatrack wrote on 08/02/2007 04:22 +0100:
>>> Your courts are at variance from those in the US in many instances, I
>>> believe. Here, it is not uncommon for the result of a civil suit to
>>> be dramatically at variance with the law and/or the facts, due
>>> entirely to the effects of the "who has the better lawyer" rule.


> Tony Raven <[email protected]> wrote:
>> That's because we use an expert judge and you use a lay jury to hear the
>> case. We reserve the lay jury for the appeal to the House of Lords ;-)


Patrick Lamb wrote:
> I was going to note that an appeal to expert judges might be
> considered preferable, until I remembered the political hacks that
> inhabit our (US) Supreme Court.


Ignoring that gratuitous swipe, the US system does have several expert
courts for specific areas of the law. None for cycling. . . yet!
/ignore
If it's any consolation, large numbers of Americans of all political
stripes think the Supremes are biased against their interests -including
many of the presidents who appointed the waffling creeps.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971