Sportsman saved by helmet. Makes you wonder how light a cycle helmetcould be and still work right.

On 20/07/14 10:27, Joe Riel wrote:
Andre Jute writes:

Sportsman saved by helmet, including wheel running over his head.
http://www.bbc.com/sport/0/formula1/28334565
Makes you wonder how light a cycle helmet could be and still work right.

A wheel didn't run over his head, his car went off the track into a
barrier made of stacked tires. The helmet worked mainly because he was
surrounded by a vehicle and crash cage designed for such impacts.


That's what I need for my bicycle - a crash cage with air bags and
crumple zones, etc. I think I'd need a motor to propel it. They
already make such a thing. It's called a motor vehicle.

--
JS

On Mon, 21 Jul 2014 08:58:56 +1000, James
wrote:

On 20/07/14 10:27, Joe Riel wrote:
Andre Jute writes:

Sportsman saved by helmet, including wheel running over his head.
http://www.bbc.com/sport/0/formula1/28334565
Makes you wonder how light a cycle helmet could be and still work right.

A wheel didn't run over his head, his car went off the track into a
barrier made of stacked tires. The helmet worked mainly because he was
surrounded by a vehicle and crash cage designed for such impacts.


That's what I need for my bicycle - a crash cage with air bags and
crumple zones, etc. I think I'd need a motor to propel it. They
already make such a thing. It's called a motor vehicle.

Naw, James.
If we make it out of foam it will be light can be :-)
--
Cheers,

John B.

On Sunday, July 20, 2014 11:53:43 PM UTC+1, James wrote:
On 19/07/14 12:26, Andre Jute wrote:

Sportsman saved by helmet, including wheel running over his head.
http://www.bbc.com/sport/0/formula1/28334565
Makes you wonder how light a cycle helmet could be and still work right..

No. I am not wondering, and I prefer not to find out - ever.

That's your privilege, James. But it seems to me that sooner or later the gubbermint will arrive at setting some kind of a "standard" for bicycle helmets, and cyclists should at least be ready with an idea of what an ideal helmet should be like, because if it is left to Big Helmet, they will try for a "standard" even limper than the present one, which, I remind you, is a retreat from an earlier, higher standard.

Andre Jute
Of course self-regulation works - for the regulators

On 21/07/14 10:59, Andre Jute wrote:
On Sunday, July 20, 2014 11:53:43 PM UTC+1, James wrote:
On 19/07/14 12:26, Andre Jute wrote:

Sportsman saved by helmet, including wheel running over his
head. http://www.bbc.com/sport/0/formula1/28334565 Makes you
wonder how light a cycle helmet could be and still work right.

No. I am not wondering, and I prefer not to find out - ever.

That's your privilege, James. But it seems to me that sooner or later
the gubbermint will arrive at setting some kind of a "standard" for
bicycle helmets, and cyclists should at least be ready with an idea
of what an ideal helmet should be like, because if it is left to Big
Helmet, they will try for a "standard" even limper than the present
one, which, I remind you, is a retreat from an earlier, higher
standard.


I hope they make it so limp it's obvious the thing doesn't afford any
more protection than a cloth hat. At that point the repeal of the
mandatory skid lid law will be a no-brainer, and some of those 60% of
school kids who stopped riding when the law was brought in will start
riding again - for everyone's sake.

--
JS

On Monday, July 21, 2014 2:17:57 AM UTC+1, James wrote:
On 21/07/14 10:59, Andre Jute wrote:

On Sunday, July 20, 2014 11:53:43 PM UTC+1, James wrote:

On 19/07/14 12:26, Andre Jute wrote:



Sportsman saved by helmet, including wheel running over his

head. http://www.bbc.com/sport/0/formula1/28334565 Makes you

wonder how light a cycle helmet could be and still work right.



No. I am not wondering, and I prefer not to find out - ever.



That's your privilege, James. But it seems to me that sooner or later

the gubbermint will arrive at setting some kind of a "standard" for

bicycle helmets, and cyclists should at least be ready with an idea

of what an ideal helmet should be like, because if it is left to Big

Helmet, they will try for a "standard" even limper than the present

one, which, I remind you, is a retreat from an earlier, higher

standard.





I hope they make it so limp it's obvious the thing doesn't afford any

more protection than a cloth hat. At that point the repeal of the

mandatory skid lid law will be a no-brainer, and some of those 60% of

school kids who stopped riding when the law was brought in will start

riding again - for everyone's sake.



--

JS

"At that point the repeal of the mandatory skid lid law will be a no-brainer"

When you see politicians do something right because it is a no-brainer, do let me know. I'd like to see it just once.

" those 60% of school kids who stopped riding when the law was brought in"

I'm not arguing this again. It's impossible to prove or disprove, it's irrelevant to saving lives, as a rational argument it holds zero water, and as a political argument it confers zero leverage because the politcal reality is the bird in hand, not pie in sky about how many cyclists there would be if helmets were not mandatory.

I'm not interested in old politics, however it is dressed up. I just want to know if a cycling helmet that works well can be made light enough to be feasible.

And I think I've been reminded by Jeff that I've been carrying the answer around in my shirt pocket for several years: Non-Newtonian Fluid. My leather iPhone cover with D30 weighs a fraction of what the hefty rubber and plastic Griffin Survivor for the iPhone weighs (I have both, both work).

Not going to happen though, because there's stiction in both the cycling community, of which your attitude is a fair example, and among the helmet manufacturers, of whose attitude the retreat from an acknowledged superior standard is a fair example.

Too bad. The only people who will be screwed will be cyclists. It'll be the worst of both worlds: mandatory helmets, helmets that don't work. Par for the course, I suppose.

Andre Jute
For now just taking names

On Sun, 20 Jul 2014 19:15:01 -0700 (PDT), Andre Jute
wrote:

And I think I've been reminded by Jeff that I've been carrying
the answer around in my shirt pocket for several years:
Non-Newtonian Fluid. My leather iPhone cover with D30 weighs a
fraction of what the hefty rubber and plastic Griffin Survivor
for the iPhone weighs (I have both, both work).

It's nothing new. It's just new for cycling helmets. Various
non-Newtonian fluids used as a dilatant[1], have been developed for
use in football helmets, protective clothing, armor, and other impact
absorbers. For example:
http://www.reuters.com/article/2014/01/08/us-usa-football-concussion-idUSBREA071IH20140108
http://footballphysics.utk.edu/pads/seeing_is_believing.htm
https://www.youtube.com/watch?v=JIFMW-ccr9I (2:59)
https://www.youtube.com/watch?v=_ThtQkkXvdo (4:31)
http://en.wikipedia.org/wiki/D3o

There are various mechanisms to make it work, but they all do several
things:
1. The dilatant extends the time of impact length of time, thus
reducing the amount of energy (or work) applied to the head. It's
like the difference between a sudden impact versus an equal amount of
force applied by pushing.
2. Changes the direction to perpendicular to the line of impact. This
tends to spread the force over a much larger area, which is more
easily absorbed.
3. Dissipates energy by some form of motion, such as compressing
foam, squeezing a fluid through an orifice, or ablation.

Not going to happen though, because there's stiction in both
the cycling community, of which your attitude is a fair example,
and among the helmet manufacturers, of whose attitude the retreat
from an acknowledged superior standard is a fair example.

My guess(tm) is that the concept will need to be proven in football,
motorcycle, climbing, equestrian, and BMX helmets, before it can be
sold to cyclists. The problem is that while the participants in all
the aforementioned activities recognize the need for a protective
helmet, cyclists do not. So, why should a manufacturer spend time or
money trying to sell to a reactionary and hostile market group, when
there are others willing to pay good money for improved protection?

Too bad. The only people who will be screwed will be cyclists. It'll
be the worst of both worlds: mandatory helmets, helmets that don't
work. Par for the course, I suppose.

Sure. While superior helmets will be developed for other activities,
cyclists are conservative and will only buy the currently available
products. When it eventually becomes apparent that there's something
better available, the helmet manufacturers will protect their market
by convincing politicians to make the current helmet products
mandatory. Never mind safety. It's sales that are important.

Andre Jute
For now just taking names


[1] http://en.wikipedia.org/wiki/Dilatant

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Monday, July 21, 2014 1:56:50 AM UTC-4, Jeff Liebermann wrote:
On Sun, 20 Jul 2014 19:15:01 -0700 (PDT), Andre Jute

wrote:



And I think I've been reminded by Jeff that I've been carrying

the answer around in my shirt pocket for several years:

Non-Newtonian Fluid. My leather iPhone cover with D30 weighs a

fraction of what the hefty rubber and plastic Griffin Survivor

for the iPhone weighs (I have both, both work).



It's nothing new. It's just new for cycling helmets. Various

non-Newtonian fluids used as a dilatant[1], have been developed for

use in football helmets, protective clothing, armor, and other impact

absorbers. For example:

http://www.reuters.com/article/2014/01/08/us-usa-football-concussion-idUSBREA071IH20140108

http://footballphysics.utk.edu/pads/seeing_is_believing.htm

https://www.youtube.com/watch?v=JIFMW-ccr9I (2:59)

https://www.youtube.com/watch?v=_ThtQkkXvdo (4:31)

http://en.wikipedia.org/wiki/D3o



There are various mechanisms to make it work, but they all do several

things:

1. The dilatant extends the time of impact length of time, thus

reducing the amount of energy (or work) applied to the head. It's

like the difference between a sudden impact versus an equal amount of

force applied by pushing.

2. Changes the direction to perpendicular to the line of impact. This

tends to spread the force over a much larger area, which is more

easily absorbed.

3. Dissipates energy by some form of motion, such as compressing

foam, squeezing a fluid through an orifice, or ablation.



Not going to happen though, because there's stiction in both

the cycling community, of which your attitude is a fair example,

and among the helmet manufacturers, of whose attitude the retreat

from an acknowledged superior standard is a fair example.



My guess(tm) is that the concept will need to be proven in football,

motorcycle, climbing, equestrian, and BMX helmets, before it can be

sold to cyclists. The problem is that while the participants in all

the aforementioned activities recognize the need for a protective

helmet, cyclists do not. So, why should a manufacturer spend time or

money trying to sell to a reactionary and hostile market group, when

there are others willing to pay good money for improved protection?



Too bad. The only people who will be screwed will be cyclists. It'll

be the worst of both worlds: mandatory helmets, helmets that don't

work. Par for the course, I suppose.



Sure. While superior helmets will be developed for other activities,

cyclists are conservative and will only buy the currently available

products. When it eventually becomes apparent that there's something

better available, the helmet manufacturers will protect their market

by convincing politicians to make the current helmet products

mandatory. Never mind safety. It's sales that are important.



Andre Jute

For now just taking names





[1] http://en.wikipedia.org/wiki/Dilatant



--

Jeff Liebermann

150 Felker St #D http://www.LearnByDestroying.com

Santa Cruz CA 95060 http://802.11junk.com

Skype: JeffLiebermann AE6KS 831-336-2558

Weight and comfort in hot humid weather are two things I look for in a helmet. Protection is good but only if the helmet is not so heavey or uncomfortable that one doesn't want to wear it. Bicycling generates a fair bit of heat in the body and the head is a prime area that needs to be kept cool. There are an awful lot of helmets out there that do not allow much cooling of the head.

Cheers

On 7/21/2014 1:56 AM, Jeff Liebermann wrote:


My guess(tm) is that the concept will need to be proven in football,
motorcycle, climbing, equestrian, and BMX helmets, before it can be
sold to cyclists. The problem is that while the participants in all
the aforementioned activities recognize the need for a protective
helmet, cyclists do not.

Most cyclists do not recognize a need for a protective helmet because
most cyclists do not need a protective helmet. IOW, their estimate of
the (tiny) risk is correct.

A few classes of cyclists do believe helmets are really necessary. For
example:

* The riders who "need" a helmet because their government will fine them
if they dare ride without one. It's government idiocy, and it hurts
cycling and cyclists. But if those riders want to avoid fines, they do
need a helmet. But any helmet will do.

* The mountain bikers who recently built a series of renegade ramps and
"features" in our local forest preserve (since dismantled). They are
probably correct in their guess that their stunting makes them more
likely to hit their heads, and that the impact will be within the very
limited capacity of their helmets.

* The riders who adopt the style choices of Tour de France competitors.
Now that those racers are required to wear helmets, one can't
fantasize about riding like they do unless one dons the proper plastic
hat. The old-style pre-mandate hat
http://images.delcampe.com/img_large...70/842_001.jpg
just doesn't fit the fantasy. You "need" what your heroes now wear.

* The great majority of believers who have been sucked in by fear
mongering propaganda. They've been convinced that even very tame
bicycling is a great risk for serious brain injury. Obviously, they've
never bothered to look for comparative data that shows that cycling is
extremely safe - for example, that bicyclists are only 0.6% of traumatic
brain injury fatalities. So these people really don't need a helmet;
but they _believe_ they do.

Even so, the vast majority of cyclists don't believe they need a helmet.

And there's the further problem that the believers have been convinced
that current helmets are magic. Why, they prevent "up to 85%" of head
injuries! (Um... even if the NHTSA says that claim is false and should
not be used...) So it will be tricky for manufacturers to convince them
that the magic hats they've sold for decades are not sufficiently magic.

So, why should a manufacturer spend time or
money trying to sell to a reactionary and hostile market group, when
there are others willing to pay good money for improved protection?

Exactly. It's far easier to just keep running the styrofoam machines.
And, of course, the propaganda machines.

--
- Frank Krygowski

On Mon, 21 Jul 2014 08:08:09 -0700 (PDT), Sir Ridesalot
wrote:

Weight and comfort in hot humid weather are two things I
look for in a helmet. Protection is good but only if the
helmet is not so heavey or uncomfortable that one doesn't
want to wear it. Bicycling generates a fair bit of heat in
the body and the head is a prime area that needs to be kept
cool. There are an awful lot of helmets out there that do
not allow much cooling of the head.

Cheers

Yep, cooling is a problem. In order to spread the force of an impact
over as large an area as possible, the helmet has to have as much
surface contact with the head as possible. That blocks any air flow
and cooling. So, other means of cooling are required.

I can conjure various schemes to elevate the shock absorbing pads
above the head, and rapidly fill the gap during an impact. Conical
shock pads would do that. Maybe just forced air cooling will suffice.
Or, I can recirculate a fluid in the helmet and dissipate the heat in
an external radiator. Maybe an inverted water bottle on top of the
helmet, that drips water on your head, and cools by evaporation. The
problem is that such schemes are complex, messy, ugly, and expensive.
Wearing a refrigerator on my head doesn't sound very appealing.
However, I'm fairly sure I can make any of these ideas work. Whether
the price, weight, appearance, and effectiveness is deemed acceptable
will be the real problems.

Note that this is not a new problem, as the military in hot climates,
race car drivers, and fire fighters have a similar problem. Examples:
http://ktm390duke.com/forum/attachments/113d1403626440-07.jpg
http://www.circletrack.com/howto/ctrp_0709_keeping_coole_when_racing/viewall.html
http://www.circletrack.com/techarticles/driver_cooling_system_tech_types_review/
http://www.thefirestore.com/store/category.aspx/categoryId/829/Cooling-Apparel/



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Frank Krygowski writes:

And there's the further problem that the believers have been convinced
that current helmets are magic. Why, they prevent "up to 85%" of head
injuries! (Um... even if the NHTSA says that claim is false and
should not be used...) So it will be tricky for manufacturers to
convince them that the magic hats they've sold for decades are not
sufficiently magic.

Apparently 85% wasn't enough. See http://www.safekids.org/bike:
"Helmets can reduce the risk of severe brain injury by 88 percent."
No citation, of course.

--
Joe Riel