Re: published helmet research - not troll



Bill "Laa laa I'm not listening" Zaumen trolled:

> Back to ignoring Guy ... he's sliding back into infant mode.


Translation: "Laa laa I'm not listening"

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University
 
"Just zis Guy, you know?" <[email protected]> writes:

> Bill "Laa laa I'm not listening" Zaumen wrote:
>
> [a load of bile followed by:]


The truth: Guy posted an ad hominem attack climbing, with zero
justification, that I had lied. I told him off relatively politely.
No wonder he wants to snip it. His behavior is an embarassment
even to him (or if not, it should be.)


> So, the Bell V1, a minimally-vented helmet with better aerodynamics than a
> standard modern hlemt increases drag by 9.8%, while long hair increases drag
> by 8.6%. In other words, a helmet which was if anything more aerodynamic
> than a modern helmet, due to its smoother profile, increases drag by 13%
> more than long hair.


Sigh. Your 13% should ahve been 1.2 percent, and the symmetric Bell V1 Pro
is not as good as newer designs in terms of air-drag reduction.

It is well known that filling in the space behind an object decreases
air resistance. See Bicycling Science, figures 4.5 and 4.6. Figure
4.5 shows fairings that extend behind the cyclist. Compare that to a
modern helmet, with a tapered section behind the head.

> Even the best-case scenario for an ANSI approved lid, the Bell Stratos,
> increases drag compared with a bald head or rubber cap, both of which have
> been sported by racing cyclists in the past. This helmet was reputedly
> unusable due to heat buildup, unless you dispensed witht he visor - in which
> case of course some of the aero advantage was lost.


This is completely irrelevant. The statement was that it decreased drag
for cyclists (who typically have hair on their heads.) It doesn't
particularly matter if some sort of rubber cap would work as well or
even if some non-protective cap would work better, since the claim was
simply a slight air drag reduction.

> Head fairings, no longer allowed by UCI, reduce drag by around 2% in wind
> tunnel conditions, but experience indicates that bare-headed (not, I think,
> bald, incidentally) racers have beaten racers wearing head fairings in
> identical conditions in time trials, which indicates that even these savings
> may not be realised in practice.
>
> Conclusion from the link you posted: helmets in general increase drag.
>
> > Your recorded instance doesn't show that he wouldn't have gone even
> > faster if he used a helmet. I'll snip the rest of your rantings.
> > They aren't worth replying to if you can't even understand that
> > some people ride faster than others, or have an exceptionally good
> > day on occassion.


> You /could/ assume that the rider in question was having an exceptionally
> good day, and everyone else was having a bad day, and there was a bit of a
> gust of tailwind for a crucial period when he alone was placed to benefit
> from it, and any number of other implausible ideas - or you /could/ apply
> Occam's Razor, remove all the guesswork, and conclude that even the most
> aerodynamic headgear makes no difference, as indicated by Rinard's research.
>
> My money is on Rinard.


Put your money on whomever you like, but the fact is that a tail wind
decreases the advantage you get from an aerodynamically shaped helmet.
Your "gust of tailwind" for one rider alone is a silly strawman
argument. If all riders have a tailwind, reducing air drag by any
means buys you less than when riding in still air or when there is
a head wind.

You simply cannot draw the conclusion you want to. All the evidence
is that the winner would have won by even more with some air drag
reduction. Why is that so hard for you to understand?

--
My real name backwards: nemuaZ lliB
 
"Just zis Guy, you know?" <[email protected]> writes:

> Bill "Laa laa I'm not listening" Zaumen trolled:
>
> > You can't just admit you were wrong and have to add one of your
> > idiotic insults?

>
> If Tom and Frank are wrong, so is Damon Rinard, and your sole piece of
> supporting evidence vanishes, leaving you in the usual position of having no
> facts to support you.


The facts are self evident. Tom has shown himself to be a liar, Frank's
posts usually qualify as "spin", and you can't even bring yourself to
admit that your counterexample is pure BS. The guy simply won a race.
Big deal. It has nothing to do with what we are discussing - the facts
are that he would simply have won by more if he used an appropriately
shaped helmet to reduce air drag.

--
My real name backwards: nemuaZ lliB
 
"Bill Z." <[email protected]> wrote in message
news:[email protected]...
>
> You are an infant babbling in baby talk and Kunich lied repeated,
> including a recent complete fabrication about a supposed something
> or other at my job. The fact is that he really is a bald-faced
> liar, and it is not confusion on his part because he's repeated
> the same bald-faced lies any number of times.


Sorry Zaumen, I remember those postings quite accurately in context if not
in exact content. Some one on the group asked for some information, you
responded with your usual know-it-all **** and someone else from Sun
corrected you and told you to shut up about things you know nothing about.
When you replied with your name calling he threatened to report you to your
supervisor for giving out false information to Sun customers and you
appologized and kissed his butt for a full posting.

Far as I can remember it was the only time I've ever seen a posting from you
that appologized for any of your cheap ****.

> The links I posted listed air drag for several helmets, some of which
> reduced air drag for cyclists are aren't completely bald.


Sorry, you are misrepresenting the true contents of the website. The entire
article was comparing the cost per possible savings in aerodynamic drag. The
5% "savings" was the worst case and reflected a 5% savings in aerodynamic
drag over a bare head with long hair vs. a special aerodymanic TT helmet
that was discontinued after only a short time as usuable by racers and
impossible to use for street riders. As is usual, since you don't have a
clue about anything you talk so casually about, the reduction wasn't in
overall drag but only relative drag of the head.

> > Modern helmets have many more vents, making them dirtier
> > aerodynamically. There is a recorded instance of an individual in a
> > TdF time trial, against the clock with no peloton, remember, beating
> > the field despite their using head fairings, which are the most
> > aerodynamic headgear available and undoubtedly more aerodynamic than
> > the new aero helmets, which have a larger frontal area.

>
> Your recorded instance doesn't show that he wouldn't have gone even
> faster if he used a helmet. I'll snip the rest of your rantings.
> They aren't worth replying to if you can't even understand that
> some people ride faster than others, or have an exceptionally good
> day on occassion.


Right, but history does show that this was one of the very rare instances
when Lance Armstrong was beaten in a Tour de France TT and Botero NEVER BEAT
HIM AGAIN. Moreover, Lance was second and ahead of David Miller, one of the
world's fastest in the Time Trial.

So again you are shown to know absolutely nothing about what you're talking
about. Another HUGE surprise to no one.
 
"Tom Kunich" <[email protected]> writes:

> "Bill Z." <[email protected]> wrote in message
> news:[email protected]...
> >
> > You are an infant babbling in baby talk and Kunich lied repeated,
> > including a recent complete fabrication about a supposed something
> > or other at my job. The fact is that he really is a bald-faced
> > liar, and it is not confusion on his part because he's repeated
> > the same bald-faced lies any number of times.

>
> Sorry Zaumen, I remember those postings quite accurately in context if not
> in exact content. Some one on the group asked for some information, you
> responded with your usual know-it-all **** and someone else from Sun
> corrected you and told you to shut up about things you know nothing about.

<snip>

Kunich, you are lying through your ****ing teeth. Just a few weeks ago
when you posted similar libelous statements, you couldn't back them up
with a URL to *any* post on *any* such group. The only thing saving
you from a lawsuit for libel is that you are such a well-known slimeball
that nobody in his right mind would take you seriously.

If you keep it up and I finally get fed up with you, however, we might
just end up settling it in a court of law, and with your history, I'd
have no trouble proving malice.

I'd suggest you either produce a URL showing these alledged posts,
which you won't be able to do, or post a public apology.

--
My real name backwards: nemuaZ lliB
 
Bill "Laa laa I'm not listening" Zaumen wrote:

[pathetic excuses for a load of bile followed by]

>> So, the Bell V1, a minimally-vented helmet with better aerodynamics
>> than a standard modern hlemt increases drag by 9.8%, while long hair
>> increases drag by 8.6%. In other words, a helmet which was if
>> anything more aerodynamic than a modern helmet, due to its smoother
>> profile, increases drag by 13% more than long hair.


> Sigh. Your 13% should ahve been 1.2 percent, and the symmetric Bell
> V1 Pro is not as good as newer designs in terms of air-drag reduction.


Ah, I wondered if you were going to do a Crook & Feikh and confuse
percentage difference with percentage points difference.

The V1 Pro increases drag by 9.8%, long hair by 8.6%, so the V1 pro
increases drag by just shy of 14% more than does long hair, that is to say
its aerodynamic performance would have to be improved by 14% to reach the
worst-case unhelmetd scenario of long hair. To reach the aero performance
of more typical short hair, the aerodynamic performance of the V1 would have
to be improved by over half.

We have had plenty of reasons advanced why a modern multi-vented helmet
might perform worse than a V1, but none which would account for better
performance, and certainyl none which would acount for performance
improvements of the magnitude required. Which is probably why the helmet
manufacturers are not making these claims: they are not true.

> It is well known that filling in the space behind an object decreases
> air resistance. See Bicycling Science, figures 4.5 and 4.6. Figure
> 4.5 shows fairings that extend behind the cyclist. Compare that to a
> modern helmet, with a tapered section behind the head.


Up to a point, with certain caveats. Most helmets do not do this. If you
are still insisiting on pretending that aero shells are typical of the
aerodynamic performance of helmets then this whole argument is more
pointless than usual.

Exhibit A: The Bell Ghisallo, a typical modern helmet:
http://www.cbike.com/bell_helmets.htm

Far from tapering off at the back, the rear face of the Ghisallo is
vertical. In a normal riding attitude the rear of the helmet is higher than
the part over the centre of the skull. So, no evidence of aero advantage
there. The Z1 had a relatively few vents and a fairly smooth surface, not
punctured by those enormous drag-producing slots seen in the Ghisallo and
other modern helmets.

But do tell: how have helmet manufacturers managed to effect this doubling
of aerodynamic performance and why are they keeping so quiet about it?

>> Even the best-case scenario for an ANSI approved lid, the Bell
>> Stratos, increases drag compared with a bald head or rubber cap,
>> both of which have been sported by racing cyclists in the past.
>> This helmet was reputedly unusable due to heat buildup, unless you
>> dispensed witht he visor - in which case of course some of the aero
>> advantage was lost.


> This is completely irrelevant. The statement was that it decreased
> drag for cyclists (who typically have hair on their heads.)


We are talking about time trial helmets here, and in time trials racers will
do all kinds of stuff for aero advantage. Wearing a rubber cap or having a
head shave is no more of a hardship than having your legs waxed, which they
don't think twice about.

> It
> doesn't particularly matter if some sort of rubber cap would work as
> well or
> even if some non-protective cap would work better, since the claim was
> simply a slight air drag reduction.


Your claim was a slight drag reduction from a standard helmet. That is
resoundingly rebutted: there is massively more evidence in the sources you
quote for standard helmets increasing darg than for them reducing drag.
There may well be some slight reduction from time trial aero helmets, but
these are only worn for time trials, and the evidence of actual race
performance seems to indicate that even this benefit may be illusory outside
the wind tunnel.

>> You /could/ assume that the rider in question was having an
>> exceptionally good day, and everyone else was having a bad day, and
>> there was a bit of a gust of tailwind for a crucial period when he
>> alone was placed to benefit from it, and any number of other
>> implausible ideas - or you /could/ apply Occam's Razor, remove all
>> the guesswork, and conclude that even the most aerodynamic headgear
>> makes no difference, as indicated by Rinard's research.
>> My money is on Rinard.


> Put your money on whomever you like, but the fact is that a tail wind
> decreases the advantage you get from an aerodynamically shaped helmet.
> Your "gust of tailwind" for one rider alone is a silly strawman
> argument. If all riders have a tailwind, reducing air drag by any
> means buys you less than when riding in still air or when there is
> a head wind.


They are riding at speeds where that is not going to make enough difference.
Remember, the guy had to beat Lance Armstrong.

> You simply cannot draw the conclusion you want to. All the evidence
> is that the winner would have won by even more with some air drag
> reduction. Why is that so hard for you to understand?


LOL! You have finally disappeared up your own ****! In case you'd
forgotten, you are the one asserting aero benefit, and you are the one who
has failed to do so even in the limited case of time trials where the
headgear is actually specifically designed to reduce drag; and remember,
this was in 2002 when TT head fairings were not ANSI certified, and thus
bigger.

Now tell us again what leads you to conclude that most helmets improve
aerodynamics, citing references which actually support your assertion rather
than undermining it.

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University
 
Bill "Laa laa I'm not listening" Zaumen trolled:

>> If Tom and Frank are wrong, so is Damon Rinard, and your sole piece
>> of supporting evidence vanishes, leaving you in the usual position
>> of having no facts to support you.


> The facts are self evident.


This is true: the Rinard site says that a standard helmet of those days,
which is more aerodynamic (or rather, less unaerodynamic) than a current
helmet, is actually worse than the worst-case unhelmeted scenario of long
hair. All the ad-hominem in the world doesn't change the fact that you
yourself posted the link which disproves your assertion, or indeed the fact
that the makers themselves, rarely reluctant to claim whatever benefit they
legitimately may, make no such claims. You have advanced no evidence to
support the idea that a modern helmet is any more aerodynamic than the Bell
Z1 Pro, let alone the massive improvement which would be necessary to reach
the aerodynamic performance of bare head / short hair.

And even in the strictly limited case of an aero shell (pre-ANSI
requirements) is shown to be of marginal benefit at best. And if you'd
followed Tom's link you'd ahve known that the light breeze on the day was
offshore, so predominantly across the course, and the Botero's winning
average speed was over 50 km/h compared to a peak wind speed of 15 km/h - a
speed difference more than enough for aero advantage to tell even had the
wind been dead behind them.

There really is not all that much more to be said, unless you can come up
with some evidence to support your assertion.

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University
 
Tom Kunich wrote:

>> The links I posted listed air drag for several helmets, some of which
>> reduced air drag for cyclists are aren't completely bald.


> Sorry, you are misrepresenting the true contents of the website.


Do you think we'd better tell Zaumie that Damon Rinard has a link on his
site to my "helmet wars" page
http://www.chapmancentral.co.uk/web/public.nsf/Documents/why-helmets ?

> Right, but history does show that this was one of the very rare
> instances when Lance Armstrong was beaten in a Tour de France TT and
> Botero NEVER BEAT HIM AGAIN. Moreover, Lance was second and ahead of
> David Miller, one of the world's fastest in the Time Trial.


And if Zaumie had read the report you linked he'd know the tailwind idea is
a red herring anyway :)

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University
 
"Just zis Guy, you know?" <[email protected]> writes:

> Bill "Laa laa I'm not listening" Zaumen wrote:
>
> [pathetic excuses for a load of bile followed by]
>
> >> So, the Bell V1, a minimally-vented helmet with better aerodynamics
> >> than a standard modern hlemt increases drag by 9.8%, while long hair
> >> increases drag by 8.6%. In other words, a helmet which was if
> >> anything more aerodynamic than a modern helmet, due to its smoother
> >> profile, increases drag by 13% more than long hair.

>
> > Sigh. Your 13% should ahve been 1.2 percent, and the symmetric Bell
> > V1 Pro is not as good as newer designs in terms of air-drag reduction.

>
> Ah, I wondered if you were going to do a Crook & Feikh and confuse
> percentage difference with percentage points difference.


Your text clearly indicated a percentage point difference. Nobody
expresses differences as percentages of percentages.

>
> We have had plenty of reasons advanced why a modern multi-vented helmet
> might perform worse than a V1, but none which would account for better
> performance, and certainyl none which would acount for performance
> improvements of the magnitude required.


Oh, this is pure BS on your part. The teardrop shape certainly helps,
and the V1 pro itself had multiple vents.


> Which is probably why the helmet manufacturers are not making these
> claims: they are not true.


It is more likely because a tiny increase over a bare head is not
a marketing claim relevant to most cyclists.

> > It is well known that filling in the space behind an object decreases
> > air resistance. See Bicycling Science, figures 4.5 and 4.6. Figure
> > 4.5 shows fairings that extend behind the cyclist. Compare that to a
> > modern helmet, with a tapered section behind the head.

>
> Up to a point, with certain caveats. Most helmets do not do this.


Yes they *do* do that, to a small extent.


> If you are still insisiting on pretending that aero shells are
> typical of the aerodynamic performance of helmets then this whole
> argument is more pointless than usual.


Well, that is another of your lies ... I never said that.

> >> Even the best-case scenario for an ANSI approved lid, the Bell
> >> Stratos, increases drag compared with a bald head or rubber cap,
> >> both of which have been sported by racing cyclists in the past.


So what? Most of us are not racers. A slight decrease in drag over
a bare head, or just breaking even, is fine with me.

> We are talking about time trial helmets here, and in time trials
> racers will do all kinds of stuff for aero advantage. Wearing a
> rubber cap or having a head shave is no more of a hardship than
> having your legs waxed, which they don't think twice about.


You were talking about time trials. I could actually care less.
>
> Your claim was a slight drag reduction from a standard helmet. That is
> resoundingly rebutted: there is massively more evidence in the sources you
> quote for standard helmets increasing darg than for them reducing drag.


No there isn't any such evidence.

> > Put your money on whomever you like, but the fact is that a tail wind
> > decreases the advantage you get from an aerodynamically shaped helmet.
> > Your "gust of tailwind" for one rider alone is a silly strawman
> > argument. If all riders have a tailwind, reducing air drag by any
> > means buys you less than when riding in still air or when there is
> > a head wind.

>
> They are riding at speeds where that is not going to make enough difference.
> Remember, the guy had to beat Lance Armstrong.


Oh that's nonsense. A 5 to 10 mph tail wind is going to make a
noticable difference to someone riding at 30 mph or so.

> LOL! You have finally disappeared up your own ****! In case you'd
> forgotten, you are the one asserting aero benefit, and you are the one who
> has failed to do so even in the limited case of time trials where the
> headgear is actually specifically designed to reduce drag; and remember,
> this was in 2002 when TT head fairings were not ANSI certified, and thus
> bigger.


In case you've forgotten, *you* were basing your claims on the idiotic
statement that because some guy won a race without a helmet, that somehow
showed something about the helmets aerodynamic characteristics, and that
is simply absurd. It completely ignores how much effort a given rider
puts out (and this is in a multi-day race, where saving energy for the
next day can be a factor for some riders but not others.)


--
My real name backwards: nemuaZ lliB
 
"Just zis Guy, you know?" <[email protected]> writes:

> Bill "Laa laa I'm not listening" Zaumen trolled:
>
> >> If Tom and Frank are wrong, so is Damon Rinard, and your sole piece
> >> of supporting evidence vanishes, leaving you in the usual position
> >> of having no facts to support you.

>
> > The facts are self evident.

>
> This is true: the Rinard site says that a standard helmet of those days,
> which is more aerodynamic (or rather, less unaerodynamic) than a current
> helmet, is actually worse than the worst-case unhelmeted scenario of long
> hair.


The data disagrees with this assertion (and I suspect the problem is your
spin on it.) The current helmets have a more effective shape than the
older ones.

> All the ad-hominem in the world doesn't change the fact that you
> yourself posted the link which disproves your assertion


Well that is another lie - the links are to articles that show a
reduction in air drag.


--
My real name backwards: nemuaZ lliB
 
"Just zis Guy, you know?" <[email protected]> writes:

> Tom Kunich wrote:
>
> >> The links I posted listed air drag for several helmets, some of which
> >> reduced air drag for cyclists are aren't completely bald.

>
> > Sorry, you are misrepresenting the true contents of the website.

>
> Do you think we'd better tell Zaumie that Damon Rinard has a link on his
> site to my "helmet wars" page
> http://www.chapmancentral.co.uk/web/public.nsf/Documents/why-helmets ?



If so, we can either write off this Rinard character, whoever he is, or
attribute it to link rot.

--
My real name backwards: nemuaZ lliB
 
Bill "Laa laa I'm not listening" Zaumen wrote:

>> Ah, I wondered if you were going to do a Crook & Feikh and confuse
>> percentage difference with percentage points difference.


> Your text clearly indicated a percentage point difference. Nobody
> expresses differences as percentages of percentages.


No, you chose to read it that way. Once again you confuse BillWorld[tm] for
the general case.

>> We have had plenty of reasons advanced why a modern multi-vented
>> helmet might perform worse than a V1, but none which would account
>> for better performance, and certainyl none which would acount for
>> performance improvements of the magnitude required.


> Oh, this is pure BS on your part. The teardrop shape certainly helps,
> and the V1 pro itself had multiple vents.


And your proof is?... Oh, you have none. As usual. Now look at the linked
picture of the Bell Ghisallo, a typical modern helmet. It is not "teardrop
shaped", it has a pronounced DA at the back.

>> Which is probably why the helmet manufacturers are not making these
>> claims: they are not true.


> It is more likely because a tiny increase over a bare head is not
> a marketing claim relevant to most cyclists.


You are veryinventive when it comes to thinking up excuses for a lack of
evidence to support your position. So far the only actual evidence posted
directly contradicts you...

>> If you are still insisiting on pretending that aero shells are
>> typical of the aerodynamic performance of helmets then this whole
>> argument is more pointless than usual.


> Well, that is another of your lies ... I never said that.


Ah, Bill, I would count the day lost without you calling me a liar - it is
an important indicator that I am on the money.

What has happened in this thread thus far is that you have claimed helmets
improve aero, based on the evidence of the Bell Stratos, a type of helmet
you then went on to prove you had never seen and didn't understand. As
usual, when finding yourself in a hole, the usual solution - stop digging -
doesn't even occur to you. You have considered aero shells, the Stratos
helmet, 90s helmets and present-day helemts as if they are interchangeable
and barely different in their aerodynamic properties, but they are greatly
different.

Challenged to provide evidene to support your position, you posted a page
from Damon Rinard which directly contradicts your position.

I am amazed that you trust Rinard that much; his links page on cyle helmets
contains the following:

www.magma.ca/~ocbc/hfaq.html Avery Burdett's Helmet FAQ
www.chapmancentral.co.uk/web/public.nsf/Documents/why-helmets
www.ucolick.org/~de/AltTrans/helmyths.html
www.cyclehelmets.org/
www.lesberries.co.uk/cycling/helmets/research.html

Every one of these is helmet-sceptical. Surely some of your cherished True
Believers must have some evidence you can post?

>>>> Even the best-case scenario for an ANSI approved lid, the Bell
>>>> Stratos, increases drag compared with a bald head or rubber cap,
>>>> both of which have been sported by racing cyclists in the past.


> So what? Most of us are not racers. A slight decrease in drag over
> a bare head, or just breaking even, is fine with me.


Bill,. will you please try to understand before one of us dies? The slight
decrease is available solely from specially designed unvented aerodynamic
time trial helmets; standard helemts offer an increase in drag over the
worst-case unhelmeted scenario, long hair. That is the conclusion of the
reference you posted. There being no other data available, and God knows
you've had enough opportunity to find some, the case is closed: helmets in
general increase drag.

>> Your claim was a slight drag reduction from a standard helmet. That
>> is resoundingly rebutted: there is massively more evidence in the
>> sources you quote for standard helmets increasing darg than for them
>> reducing drag.


> No there isn't any such evidence.


READ THE ****ING LINK, Bill. You posted it, you go back and read it.

>> They are riding at speeds where that is not going to make enough
>> difference. Remember, the guy had to beat Lance Armstrong.


> Oh that's nonsense. A 5 to 10 mph tail wind is going to make a
> noticable difference to someone riding at 30 mph or so.


Now read the rest. The wind was not a tail wind, it was across the course.
Why do you insist on piling conjecture on assumption on speculation?
Occam's Razor indicates a much simpler answer: even head fairings make only
a marginal difference in practice.

Go back to Rinard's text.

> In case you've forgotten, *you* were basing your claims on the idiotic
> statement that because some guy won a race without a helmet, that
> somehow showed something about the helmets aerodynamic
> characteristics, and that is simply absurd. It completely ignores
> how much effort a given rider puts out (and this is in a multi-day
> race, where saving energy for the next day can be a factor for some
> riders but not others.)


Repeating your BS won't make it true. Rinard's text and Occam's Razor give
us the answer: you are wrong.

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University
 
Bill "Laa Laa I'm Not Listening" Zaumen trolled:

>> Do you think we'd better tell Zaumie that Damon Rinard has a link on
>> his site to my "helmet wars" page
>> http://www.chapmancentral.co.uk/web/public.nsf/Documents/why-helmets


> If so, we can either write off this Rinard character, whoever he is,
> or attribute it to link rot.


Fine, so that's your sole piece of evidence out the window (albeit that it
disproved your point rather than proving it).

F- must try harder.

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University
 
Bill "Laa laa I'm not listening" Zaumen trolled:

>>> The facts are self evident.


>> This is true: the Rinard site says that a standard helmet of those
>> days, which is more aerodynamic (or rather, less unaerodynamic) than
>> a current helmet, is actually worse than the worst-case unhelmeted
>> scenario of long hair.


> The data disagrees with this assertion (and I suspect the problem is
> your spin on it.) The current helmets have a more effective shape
> than the older ones.


So you assert, but with zero evidence to support you. You also ignore the
magnitude of the improvement which would be necessary to get to a case where
they were more aerodynamic than even the worst-case unhelmetd scenario,
unrestrained long hair.

You bring too much arm-waving, Bill, and not enough facts.

>> All the ad-hominem in the world doesn't change the fact that you
>> yourself posted the link which disproves your assertion


> Well that is another lie - the links are to articles that show a
> reduction in air drag.


Amazing, isn't it, how everybody but you has concluded the exact opposite?
Maybe you need to go back and read them.

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University
 
"Just zis Guy, you know?" <[email protected]> writes:

> Bill "Laa laa I'm not listening" Zaumen wrote:
>
> >> Ah, I wondered if you were going to do a Crook & Feikh and confuse
> >> percentage difference with percentage points difference.

>
> > Your text clearly indicated a percentage point difference. Nobody
> > expresses differences as percentages of percentages.

>
> No, you chose to read it that way. Once again you confuse BillWorld[tm] for
> the general case.


This is more BS on your part. You gave several percentages as changes
from a base value. Then you decided to provide a "percentage change of
a percentage" without indicating that you were doing that. That sort
of nonsense is a well-known example from "how to lie with statistics."
Either you can't write or you were trying to deliberatedly mislead
people.

> >> We have had plenty of reasons advanced why a modern multi-vented
> >> helmet might perform worse than a V1, but none which would account
> >> for better performance, and certainyl none which would acount for
> >> performance improvements of the magnitude required.


Like the teardrop shape (and you have hardly shown that it would not
cut drag slightly, which is all you need relative to a Bell V1 Pro
to see a net reduction in drag.)

>
> picture of the Bell Ghisallo, a typical modern helmet. It is not "teardrop
> shaped", it has a pronounced DA at the back.


What's a DA?

> > It is more likely because a tiny increase over a bare head is not
> > a marketing claim relevant to most cyclists.

>
> You are veryinventive when it comes to thinking up excuses for a lack of
> evidence to support your position. So far the only actual evidence posted
> directly contradicts you...


What evidence? If a 1 percent decrease in drag doesn't help sell a
helmet, do you think a manufacturer would bother talking about it?

> >> If you are still insisiting on pretending that aero shells are
> >> typical of the aerodynamic performance of helmets then this whole
> >> argument is more pointless than usual.

>
> > Well, that is another of your lies ... I never said that.

>
> Ah, Bill, I would count the day lost without you calling me a liar - it is
> an important indicator that I am on the money.


Gee. Maybe you shouldn't go around trying to put words in other people's
mouths.
>
>
> Challenged to provide evidene to support your position, you posted a page
> from Damon Rinard which directly contradicts your position.


I pointed you to some data that showed an air drag reduction for an
ANSI certified helmet.

--
My real name backwards: nemuaZ lliB
 
"Just zis Guy, you know?" <[email protected]> writes:

> Bill "Laa laa I'm not listening" Zaumen trolled:
>
> >>> The facts are self evident.

>
> >> This is true: the Rinard site says that a standard helmet of those
> >> days, which is more aerodynamic (or rather, less unaerodynamic) than
> >> a current helmet, is actually worse than the worst-case unhelmeted
> >> scenario of long hair.

>
> > The data disagrees with this assertion (and I suspect the problem is
> > your spin on it.) The current helmets have a more effective shape
> > than the older ones.

>
> So you assert, but with zero evidence to support you.


See
<http://www.mecheng.adelaide.edu.au/courses/undergrad/projects/level4papers2001/chin_lim.pdf>
and look at figure 6. With the head held in an appropriate attitude,
the air resistence drops when a helmet is used.

See <http://www.gssiweb.com/reflib/refs/28/d0000000200000069.cfm?pid=96&CFID=807492&CFTOKEN=69087813>
<http://sportsfigures.espn.com/sportsfigures/batting_quiz4.htm>
<http://wings.avkids.com/Curriculums/Sports/cyclist_summary.html>
<http://www.gugly.com/Archbikeclothing.htm>
<http://www.ul.ie/~childsp/Elements/issue2/sharpe.html>

rest of post snipped - it's time for dinner, so your remaining post
today gets ingnored as well.



--
My real name backwards: nemuaZ lliB
 
Bill "Laa laa I'm not listening" Zaumen wrote:

>>> Your text clearly indicated a percentage point difference. Nobody
>>> expresses differences as percentages of percentages.


>> No, you chose to read it that way. Once again you confuse
>> BillWorld[tm] for the general case.


> This is more BS on your part. You gave several percentages as changes
> from a base value. Then you decided to provide a "percentage change of
> a percentage" without indicating that you were doing that.


Oh do attempt to show a little intelligence. Having quoted the base
figures, the quoted difference cannot be anything but a percentage change,
rather than a percentage points difference. Of course you prefer the
percentage points difference, because it is smaller so suits your disporven
assertion, but the interpretation is perfectly valid, particularly against
the background of the opngoing argument with Crook & Feikh over their use of
percentege points difference when they should have used percentage
difference, an elementary statistical error which completely invalidated
their conclusions.

>>>> We have had plenty of reasons advanced why a modern multi-vented
>>>> helmet might perform worse than a V1, but none which would account
>>>> for better performance, and certainyl none which would acount for
>>>> performance improvements of the magnitude required.


> Like the teardrop shape (and you have hardly shown that it would not
> cut drag slightly, which is all you need relative to a Bell V1 Pro
> to see a net reduction in drag.)


WHAT teardrop shape? FFS, Bill, get down to that bike shop and actually
LOOK at some helmets!

>> picture of the Bell Ghisallo, a typical modern helmet. It is not
>> "teardrop shaped", it has a pronounced DA at the back.


> What's a DA?


Duck's ****, as personified by the hairstyles in the film Grease.

>> You are veryinventive when it comes to thinking up excuses for a
>> lack of evidence to support your position. So far the only actual
>> evidence posted directly contradicts you...


> What evidence? If a 1 percent decrease in drag doesn't help sell a
> helmet, do you think a manufacturer would bother talking about it?


The evidence yo posted, Bill, which as repeatedly pointed out puts the
standard helemt as worsethan the worst-case unhelmeted scenario of
unrestrained long hair. I do wish you would go back and read it.

>> Ah, Bill, I would count the day lost without you calling me a liar -
>> it is an important indicator that I am on the money.


> Gee. Maybe you shouldn't go around trying to put words in other
> people's mouths.


Gee, maybe you should acquire a clue some time.

>> Challenged to provide evidene to support your position, you posted a
>> page from Damon Rinard which directly contradicts your position.


> I pointed you to some data that showed an air drag reduction for an
> ANSI certified helmet.


Yes. For a Bell Stratos ANSI certified helmet which has as much in common
with the aerodynamics of a standard helmet as a Ferrari has with an SUV! A
fact which you have repeatedly ignored, because you don't like it. And that
is the aforementioned deliberate conflation of aero desgns with standard
helmets, by the way.

Anyway, since it is very evident to all concerned that you are wrong, you
now you are wrong, and you are scratching round for increasingly implausible
hypotheses to counter the evidence you yourself posted (the idea that a TdF
rider could ride 5% harder than the others one day! Incredible!), I think
that's an end of it, unless you have new evidence to offer.

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University
 
"Just zis Guy, you know?" <[email protected]> writes:

> Bill "Laa laa I'm not listening" Zaumen wrote:
>
> >>> Your text clearly indicated a percentage point difference. Nobody
> >>> expresses differences as percentages of percentages.

>
> >> No, you chose to read it that way. Once again you confuse
> >> BillWorld[tm] for the general case.

>
> > This is more BS on your part. You gave several percentages as changes
> > from a base value. Then you decided to provide a "percentage change of
> > a percentage" without indicating that you were doing that.

>
> Oh do attempt to show a little intelligence. Having quoted the base
> figures, the quoted difference cannot be anything but a percentage change,
> rather than a percentage points difference.


When you give X percent for one number and Y percent for another, no
reader would expect another number expressed as a percent to actually
be a percentage of a percent.

It is poor and confusing writing on your part (and possibly willfully
misleading, since casual readers may simply scan the text and jump to
the wrong conclusion.)

> Of course you prefer the
> percentage points difference, because it is smaller so suits your disporven
> assertion


I prefer it because it is clearer. WHen you see several numbers all
given as a percentage change from some base value, a reader shouldn't
have to cross check everything you say to see if you silently changed
that.

>
> > Like the teardrop shape (and you have hardly shown that it would not
> > cut drag slightly, which is all you need relative to a Bell V1 Pro
> > to see a net reduction in drag.)

>
> WHAT teardrop shape? FFS, Bill, get down to that bike shop and actually
> LOOK at some helmets!


Like the one I have (a standard helmet). It is teardrop in the usual
meaning of the word - it sticks out behind the head unlike the older
completely symmetric helmets.

> >> picture of the Bell Ghisallo, a typical modern helmet. It is not
> >> "teardrop shaped", it has a pronounced DA at the back.

>
> > What's a DA?

>
> Duck's ****, as personified by the hairstyles in the film Grease.


I'll describe that as teardrop shaped (unlike a duck, there is a
smooth taper at the back.)

> > What evidence? If a 1 percent decrease in drag doesn't help sell a
> > helmet, do you think a manufacturer would bother talking about it?

>
> The evidence yo posted, Bill, which as repeatedly pointed out puts the
> standard helemt as worsethan the worst-case unhelmeted scenario of
> unrestrained long hair. I do wish you would go back and read it.


That's a lie as well - the only helmet shown to be slightly worse than
long hair was a completely symmetric design - the type where you have
to look at the straps to figure out which end is which.

> >> Challenged to provide evidene to support your position, you posted a
> >> page from Damon Rinard which directly contradicts your position.


It doesn't contradict my position.

> Anyway, since it is very evident to all concerned that you are wrong,


More wishful thinking on your part. Oh, and due to your bad manners,
I'll ignore your other post today, since you still haven't grown up.



--
My real name backwards: nemuaZ lliB
 
Bill "Laa laa I'm not listening" Zaumen wrote:

>> Oh do attempt to show a little intelligence. Having quoted the base
>> figures, the quoted difference cannot be anything but a percentage
>> change, rather than a percentage points difference.


> When you give X percent for one number and Y percent for another, no
> reader would expect another number expressed as a percent to actually
> be a percentage of a percent.


Interest rates are 5%. The bank raises them to 6% Will your interest
payments increase by 1% or by 20%? But the interest rate has only risen by
1%! Using percentage points differences to de-emphasise the magnitude of
the difference between two figures is a classic technique for lying with
statistics.

In their paper in IP, Crook & Feikh used the percentage points difference
between injury figures to "prove" that helmets are over 60% effective. The
only thng is, they should have used percentage change, not pp. difference -
once that was taken into account what they actually proved was that helmets
are 186% effective, with each helemt not only making its wearer
invulnerable, but also conferring near-invulnerability on a non-wearer.

I note that you have nothing to say about the actual figures, which prove
that you are wrong. I wonder why you are arguing the toss about
mathematical niceties instead of looking at the actual data?

> It is poor and confusing writing on your part (and possibly willfully
> misleading, since casual readers may simply scan the text and jump to
> the wrong conclusion.)


Bill, I have every confidence that you will jump to the wrong conclusion
whatever presentation is used.

In this case they will jump to the right conclusion: the additional aero
drag of a helmet is over twice as great as that of short hair, and somewhat
greater than that of unrestrained long hair.

The casual reader, though, has probably already read the link you posted and
realised that you are talking out of your ****.

>> Of course you prefer the
>> percentage points difference, because it is smaller so suits your
>> disporven assertion


> I prefer it because it is clearer. WHen you see several numbers all
> given as a percentage change from some base value, a reader shouldn't
> have to cross check everything you say to see if you silently changed
> that.


See interest rates example above. Both presentations are defensible in
certain contexts, but when comparing two small percentages, using pp.
difference is more often misleading than not.

>> WHAT teardrop shape? FFS, Bill, get down to that bike shop and
>> actually LOOK at some helmets!


> Like the one I have (a standard helmet). It is teardrop in the usual
> meaning of the word - it sticks out behind the head unlike the older
> completely symmetric helmets.


Brand? Model? Not one helmet in my LBS matches that description. I was
last in a bike shop on Saturday; when were you last in a bike shop?

Note that among the text in the other "evidence" you posted is the bald
statement: "helmet will increase the frontal area of the rider's head and
this will affect the aerodynamics of the rider, thus, the rising of drag.
Therefore, helmet must have a good aerodynamics shape to minimise the effect
of the frontal area. Two track cycling helmets are used to investigate the
performances of drag in different position."

This from the only one of the batch which was actually an academic paper
rather than a discussion of track / TT racing quoting (without attribution)
the Kyle paper as already discussed (that's the one which proves you wrong,
if you remember).

>>>> picture of the Bell Ghisallo, a typical modern helmet. It is not
>>>> "teardrop shaped", it has a pronounced DA at the back.


> I'll describe that as teardrop shaped (unlike a duck, there is a
> smooth taper at the back.)


Ah, so you've never seen one. Thought not. The back of the Ghisallo is
anything but smooth.

>> The evidence yo posted, Bill, which as repeatedly pointed out puts
>> the standard helemt as worsethan the worst-case unhelmeted scenario
>> of unrestrained long hair. I do wish you would go back and read it.


> That's a lie as well - the only helmet shown to be slightly worse than
> long hair was a completely symmetric design - the type where you have
> to look at the straps to figure out which end is which.


You are drowning in your own ********, Bill! Even time trial helmets don't
realise actual drag reductions in real use, as evidence the following quote
from the "evidence" you posted: "[aero] helmets are designed to work
effectively when the rider is facing forward and not to the side. Doing so,
will not only eliminate all benefits gained with the good helmet, but may
also slow you down. And for those who still can't picture what I'm saying,
turning you head while using an aerodynamic helmet is like trying to cut a
piece of butter with the knife laying on its side rather than on its edge."

>>>> Challenged to provide evidene to support your position, you posted
>>>> a page from Damon Rinard which directly contradicts your position.


> It doesn't contradict my position.


Except in the eyes of everybody else who's read it, obviously.

I notice that you haven't responded to this:
http://groups.google.com/[email protected]

>> Anyway, since it is very evident to all concerned that you are wrong,


> More wishful thinking on your part.


You are such a classic zealot it's almost funny. How do you get the Rinard
piece to support your position, I wonder? By not reading past the abstract?
By missing out every third word? Or simply by inverting the sign of all the
drag figures? Who cares, anyway.

> Oh, and due to your bad manners,
> I'll ignore your other post today, since you still haven't grown up.


Translation: "Laa laa I'm not listening".

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University
 
"Just zis Guy, you know?" <[email protected]> writes:

> Bill "Laa laa I'm not listening" Zaumen wrote:
>
> >> Oh do attempt to show a little intelligence. Having quoted the base
> >> figures, the quoted difference cannot be anything but a percentage
> >> change, rather than a percentage points difference.

>
> > When you give X percent for one number and Y percent for another, no
> > reader would expect another number expressed as a percent to actually
> > be a percentage of a percent.

>
> Interest rates are 5%. The bank raises them to 6% Will your interest
> payments increase by 1% or by 20%?


When Alan Greenspan increases the prime interest rate from (say) 5% to
6%, every newspaper in the U.S. will describe this as a 1% increase in
the rate. This is standard usage.


> that you are wrong. I wonder why you are arguing the toss about
> mathematical niceties instead of looking at the actual data?


I already showed the flaw with your argument. You are claiming that,
because a Bell V1 Pro (a completely symmetric helmets with no "aero"
features) causes a very slight increase in drag for a rider with a
reasonable amount of hair on his head, *all* standard helmets must
too, even though the design of standard helmets changed since the
Bell V1 Pro (used in the 1980s) was designed.

>
> > It is poor and confusing writing on your part (and possibly willfully
> > misleading, since casual readers may simply scan the text and jump to
> > the wrong conclusion.)

>
> Bill, I have every confidence that you will jump to the wrong conclusion
> whatever presentation is used.


That will not change the fact that you are defending an indefensible
position. We can speculate as to whether you were trying to mislead
casual readers or simply wrote poorly, but in either case you basically
blew it.

> In this case they will jump to the right conclusion: the additional aero
> drag of a helmet is over twice as great as that of short hair, and somewhat
> greater than that of unrestrained long hair.


Which is the wrong conclusion. The Bell V1 Pro is an older,
completely symmetric design not optimized in any way for aerodynamics
in comparison to current practices. Even then, they were 1% way
from the break even point.

>
> The casual reader, though, has probably already read the link you posted and
> realised that you are talking out of your ****.


The casual reader who checked the link would damn well know I'm right
about it due to simply quoting what it said, and the vast majority of
casual readers probably have not even bothered.

<long sections of babbling, ranting, and generally insulting garbage
snipped, as Guy is still incapable of acting like an adult>


> > It doesn't contradict my position.

> Except in the eyes of everybody else who's read it, obviously.


You think you are the only person reading it, I take it?

> I notice that you haven't responded to this:
> http://groups.google.com/[email protected]


To what? Another of your posts during your time-out periods?

>
> >> Anyway, since it is very evident to all concerned that you are wrong,

>
> > More wishful thinking on your part.

>
> You are such a classic zealot it's almost funny. How do you get the Rinard
> piece to support your position, I wonder? By not reading past the abstract?
> By missing out every third word? Or simply by inverting the sign of all the
> drag figures? Who cares, anyway.


Now you really are lying. But as to "who cares, anyway" you sure the
hell do. Otherwise your long-winded rants wouldn't be 10 times longer
than what I've been posting.

--
My real name backwards: nemuaZ lliB