helmet ventilation?

In article ,
"C.J.Patten" wrote:

"(PeteCresswell)" wrote in message
...
Per Ron Hardin:
t's a 1975 Bell mushroom helmet, a pleasant sun-reflecting white with
rigid
white styrofoam insulation, so it takes off all the radiative solar heat.
That's
a huge benefit. Riding without it is much hotter, very noticeable.

Now you've got me thinking it's the color. Mine's a dark-ish grey.
Maybe a little strategically-applied spray paint...


Better yet, get some aluminum foil. It's easy to mold and with a bit of 3M
spray tack, you can stick it to the helmet.

An added plus: aliens won't be able to read your thoughts anymore.

A fine attempt at misinformation. The aluminum foil is to block
the secret government mind control signals.

--
Michael Press

On Thu, 14 Jul 2005 11:58:53 -0700, John wrote:

Oh, /that/ sort of fan. As you were, then...

Wow...."As you were" ...I haven't heard that expression since Camp
Pendleton!

As Guy is too young for National Service (aka compulsory call-up) it
probably means that he, like me, went to a grammar (high) school with a
compulsory army cadet force (CCF).


Mike

I googled around and found that you can get the article from
http://dx.doi.org/10.1046/j.1460-2687.2000.00053.x. Unfortunately you have
to pay for it...

It was also published in the Jan/Feb 2001 Bicycling Australia if you can
find a copy of that.

Nick

"C.J.Patten" wrote in message
...
Well heck, that's a tease! I gotta find that study!
Thanks for that though... good to know.


"Nick Payne" wrote in message
...
Someone at RMIT published research on this in Bicycling Australia a
couple of years back. Can't remember the exact details, but I think they
stuck temperature sensors in/on a headform, heated it, then blew air
across and measured the rate of cooling with various helmets (and also
with no helmet as a comparison). There was no correlation between price
and and how well the helmet allowed cooling to take place. Some of the
cheap helmets with what appeared to be poor ventilation were near the top
of the list and some of the expensive ones which were mostly slots were
near the bottom. And the best of the helmets allowed cooling as rapidly
as a bare head.

Nick

"C.J.Patten" wrote in message
...
I won't get in to a helmet debate. I wear one, reasons irrelevant for
this thread.

My question has to do with vents.

My current helmet is a Giro Indicator. This wasn't an expensive helmet
but it fits well.

When you spend 5 times as much to get something like a Giro Atmos (i
gather they use it on the tour?) is the ventilation that much better?
Would you notice your head staying that much cooler?

On Thu, 14 Jul 2005 21:40:58 +0100, Mike Causer
wrote:

Oh, /that/ sort of fan. As you were, then...

Wow...."As you were" ...I haven't heard that expression since Camp
Pendleton!

As Guy is too young for National Service (aka compulsory call-up) it
probably means that he, like me, went to a grammar (high) school with a
compulsory army cadet force (CCF).

Actually I went to a 1,000+ year old public school (that's Brit-speak
for a private school) which had an /optional/ combined cadet force
(CCF) which I did not join. I was an officer cadet for a short while
at University but failed medical due to asthma. This disability means
I find it hard to maintain an average speed of over 20mph for more
than a couple of hours when riding solo on open roads.

I have no idea where I got the phrase from, possibly my father (who
was in the RAF) or maybe it's just one of those British phrases you
pick up in books.


Guy
--
http://www.chapmancentral.co.uk

"Let’s have a moment of silence for all those Americans who are stuck
in traffic on their way to the gym to ride the stationary bicycle."
- Earl Blumenauer

J

Actually I went to a 1,000+ year old public school (that's Brit-speak
for a private school) which had an /optional/ combined cadet force
(CCF) which I did not join. I was an officer cadet for a short while
at University but failed medical due to asthma. This disability means
I find it hard to maintain an average speed of over 20mph for more
than a couple of hours when riding solo on open roads.

I have no idea where I got the phrase from, possibly my father (who
was in the RAF) or maybe it's just one of those British phrases you
pick up in books.


Guy
--
It's a standard military phase meaning "disregard my last command" or
something similar. I heard it used many times in the USMC, but that was
40 years ago. Don't hear it much in the civilian world.

Sorry about the asthma holding you back on your faster rides. My lungs
are fine, it's the years that have taken their toll. Can't do much
about that, except train harder.

John

On Fri, 15 Jul 2005 09:18:32 +0100, "Just zis Guy, you know?"
wrote:

Actually I went to a 1,000+ year old public school (that's Brit-speak
for a private school)

Which school managed that feat? I don't even know of any universities
anywhere that are more than a millennium old (Googling, though, there is
one that just barely qualifies: Al-Azhar in Cairo, Egypt, has been
operating since 969 AD, and 2 of them in India that predate that one by
some bit). Hmmm..

The only pre-1000 AD schools I can find in Britain a
The King's School, Canterbury (597)
King's School, Rochester (604)
St Peter's, York (627)
Warwick School (914?)
St Albans School (948)
King's School, Ely (970)
[the next one is listed as 1096, do not even close to 1000 years old]

I would guess you attended one of the latter two, unless it was one not on
the list for some reason?


Jasper

On 13 Jul 2005 21:35:29 -0700, wrote:

If you pay $130 for a helmet, it's guaranteed to keep a decapitated
head under 300 gees in a 14.01 mph impact.

Whereas if you pay $15 for a helmet, that decapitated head may not hit
300 gees until, oh, 15 or 16 mph.

OK, it's not a big difference. And nobody will ever tell you the exact
numbers. But the difference is there. The more you pay, the less
protection you get.

So if I pay $1000 I get to ride helmetless but it actually looks like I
have one?

Jasper

I submit that on or about Sun, 31 Jul 2005 04:20:36 GMT, the person
known to the court as Jasper Janssen made a
statement in Your
Honour's bundle) to the following effect:

Which school managed that feat? I don't even know of any universities
anywhere that are more than a millennium old (Googling, though, there is
one that just barely qualifies: Al-Azhar in Cairo, Egypt, has been
operating since 969 AD, and 2 of them in India that predate that one by
some bit). Hmmm..

The only pre-1000 AD schools I can find in Britain a
The King's School, Canterbury (597)
King's School, Rochester (604)
St Peter's, York (627)
Warwick School (914?)
St Albans School (948)
^^^^^^^^^^^^^^^^^^^^^^

That's the one.

King's School, Ely (970)
[the next one is listed as 1096, do not even close to 1000 years old]

I would guess you attended one of the latter two, unless it was one not on
the list for some reason?

St Albans School, Abbey Gateway, Romeland, St Albans, Herts. One of
the school buildings dates from the 12th Century, allegedly.

I'm pretty sure my history teacher was there from the outset...

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

85% of helmet statistics are made up, 69% of them at CHS, Puget Sound

On Sun, 31 Jul 2005 08:44:52 +0100, "Just zis Guy, you know?"
wrote:
I submit that on or about Sun, 31 Jul 2005 04:20:36 GMT, the person
known to the court as Jasper Janssen made a
statement in Your
Honour's bundle) to the following effect:

St Albans School (948)

St Albans School, Abbey Gateway, Romeland, St Albans, Herts. One of
the school buildings dates from the 12th Century, allegedly.

Most buildings from the 12th century don't have much more than a few walls
and a ground plan left original (not all, just most), so it's quite
possible even if it looks like a late-medieval or even 17th century
building on the outside.

Anyway: Neat.

I'm pretty sure my history teacher was there from the outset...

How very Harry Potter.


Jasper

I submit that on or about Sun, 31 Jul 2005 17:38:36 GMT, the person
known to the court as Jasper Janssen made a
statement in Your
Honour's bundle) to the following effect:

St Albans School, Abbey Gateway, Romeland, St Albans, Herts. One of
the school buildings dates from the 12th Century, allegedly.

Most buildings from the 12th century don't have much more than a few walls
and a ground plan left original (not all, just most), so it's quite
possible even if it looks like a late-medieval or even 17th century
building on the outside.

The school "chapel" was started in 1077, took some years to complete,
bits fell down, other bits were built, but some of the original still
exists.

http://www.stalbanscathedral.org.uk/

Here's the gateway building, part of the school:
http://en.wikipedia.org/wiki/St_Albans_Abbey

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

85% of helmet statistics are made up, 69% of them at CHS, Puget Sound