Helmets move on from fashion to technological safety improvements, at last.

On Sun, 3 May 2015 18:20:12 -0700 (PDT), Andre Jute
wrote:

This one would look good on a deranged cyclist like Franki-boy, and
keep him from doing harm to himself when he takes the lane, probably
by stopping him cycling altogether if not from weight then from embarrassment:

Try not to mix personalities with technology, which is much like
mixing oil and water. They don't mix well.

The ideal helmet is really a mental exercise in optimization. One
starts by defining a goal, which in this case is designing or at least
specifying a cycling helmet that would offer superior protection. One
then tries to produces a specification for such a helmet, that would
meet the primary goal, but also produce some serious compromises in
cost, size, weight, air resistance, appearance, manufacturability,
standards compliance, etc. Then, one takes the resultant abomination,
and balances these compromises, hopefully resulting in a sellable and
usable helmet. Some of the compromises may be different in the
various cycling market segments.

If I could have some useful additional safety for only a few ounces added
to my Bell Citi and Metro helmets, I would not begrudge the extra weight,
as those helmets do seem very light.. Where should the few ounces most
usefully be applied? Some kind of a HANS device?

I don't know. I would need statistics on the types of head and upper
body injuries incurred while wearing a helmet. If neck twisting is
the predominant culprit, some manner of collar to restrict rapid neck
twisting, possibly using a non-Newtonian fluid, might be useful. If
neck extension is statistically a problem worth solving, then a HANS
contrivance would be useful:
http://en.wikipedia.org/wiki/HANS_device
If back of neck injury, caused by the helmet digging into that area is
a problem, extra padding in that area would be useful. If cerebral
contusions are a problem, then anything that limits the peak velocity
of the head during impact will help, such as additional padding,
collapsible foam, corrugated crumple zones, and of course neck
support.

Doing all of these will result in something similar to the previously
mentioned "ideal" bicycle helmets, which is obvious overkill. So, one
must be selective, which requires statistics. Offhand, the crumple
zone and HANS contrivance seem the most worthwhile.

What about that neck ruff that blows up into a helmet in a milisecond
on sensing an impact that was mentioned here a few months ago? Air
has an admirable balance of absorption and displacement, or so
automobile suspension experts always reckon.

Notice that I never mentioned air bags. Pretend you've decided that
explosive driven automotive air bags are too dangers for the GUM
(great unwashed masses) and that pre-inflated air bags would be safer.
So, you design an automobile dashboard that is covered with inflated
air bags. The automobile would be undriveable and unsellable, but for
purposes of this discussion, those are not important. One day, your
automobile decides to swerve into a brick wall and your head hits the
pre-inflated air bag wall. What happens?

Well, first there's a big difference between an explosive inflated air
bag and a pre-inflated air bag. The first dissipated the energy of
your upper body slamming into the inflated bag by rapidly deflating
the bag. All the energy goes into emptying the bag from air. This
also has the added bonus of slowing the rate at which your upper body
approaches the (padded) dashboard.

However, the pre-inflated bags act more like springs than energy
absorbers. Your head and upper body hit the wall of bags and just
bounce back. All the energy you apply to the bag is returned to you
when you bounce back. Worse, your brain just keeps going forward, and
hits the inside of your skull with double the force because now the
skull is moving in the opposite direction as the brain.
http://en.wikipedia.org/wiki/Coup_contrecoup_injury

So, how to fix the problem? One way is to cover the dashboard with
water bags. When your face hits the wall of water bags, they explode,
taking the impact energy with the water. Your head goes forward, but
does not bounce back. However, the problem is that a water impact
tends to be rather hard. An improvement would be a non-Newtonian
fluid, such as corn starch. Your head still hits the starch bag hard,
but that causes redirects most of the energy perpendicular to the
point of impact. Once the initial impact pressure is relieved, the
starch becomes softer, decelerating your head slowly towards the
padded dashboard. The nice part is that there's no need for the
starch bag to burst in order to dissipate the collision energy.

Unfortunately, bicycles don't have dashboards and it's unlikely that
municipalities are going to pave the roads with corn starch bags. So,
we have to carry our air, water, or starch bags on our heads. I have
some ideas on how to make such a thing work, but not now. One thing
for sure, air bags won't work unless they provide a controlled
deflation on impact, which is difficult, expensive, and unlikely.

So, what will work? One thing is obvious from this rant is that
there's no such thing as a single helmet design that will protect
against every possible form of cycling accident. If someone tried to
make such a helmet, its size, weight, and cost would follow some of my
"ideal" helmet ideas. The best we can do is limit the protection for
specific types of injuries that the wearer is likely to encounter. For
racers, that would be high speed road and obstacle impact. For
commuters, it would side and rear impact by automobiles. For day
riders (like me) it would be falling over sideways after getting my
boot laces tangled in the crank. For BMX acrobats, landing head
first. For mountain bikers, rock penetration.

A big problem with designing the ultimate helmet is we have a fixation
on what a bicycle helmet should look like. Somehow, it still ends up
looking like a leather hair net.
https://www.google.com/search?q=bicycle+leather+hair+net&tbm=isch
It's going to take some effort to convince the public of a different
design. For example, one could build a reasonably functional bicycle
helmet from vinyl dipped chicken wire with ping pong balls between the
head and the wire. However, getting the GUM to accept that design
would be futile. Maybe an artistic cover might help:
http://www.thisblogrules.com/2010/07/bike-helmets-have-never-been-more-fun.html

Andre Jute
Fascination, I know...

More like machination.

--
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 Sun, 3 May 2015 18:41:44 -0700 (PDT), wrote:

Lieb

#13 Thou shalt not abrev (especially my name).

all impacts are rotational

Not if you're wearing a pickelhaube, which limits rotation:
https://www.google.com/search?q=pickelhaube&tbm=isch
Or maybe a Viking helmet with both pickelhaube and horns:
http://www.amazon.com/One-Adult-Plastic-Viking-Helmet/dp/B000FH9EQO
Hmmm, I wonder if those would be a useful cycling helmet accessory?

ablation ? heat generated by cushioning absorption thru impact shrinking as Bell et all..

No, not heat. If material is ejected at some velocity, the energy
(E=0.5mv^2) is carried away with the material. However, should the
ejected material eventually come to a stop, yes something might get
warm.

no reason...eyeyyhhaha pick one....for a hard shell Bell covered with a replaceable shredder covering.

Yep. That works. In addition to shredding, it could also be a
crumple zone. Think ping pong balls glued to your Bell helmet.

shredding is good at bike speeds. My tights shred n I walk away untorn. Good stuff.

Yep, I know. I was hiking and slipped. I went downhill about 30 ft
on my butt. My wallet was in one back pocket, and my collection of
maps in the other. Both were shredded along with the pocket. No
damage to my butt. However, my GPS was lost in the bushes somewhere.

you remember my account of the first corner at Bloomsburg Crit ?

No. I don't usually read your postings because it requires too much
work to decode your version of English.

Jungle Gym pile up, rider fell in front of me head snacking with a
crack occipital right on the curb. He got on n rode off.
f(B)

helmet protection stand on energy absorption research n production....
for areas other than bike helmets. Asking if FIA absorption is used
in bike helmets ?

What does FIA have to do with helmets?
http://en.wikipedia.org/wiki/Flow_injection_analysis

--
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 Sun, 03 May 2015 20:10:20 -0700, Jeff Liebermann
wrote:

Worse, your brain just keeps going forward, and
hits the inside of your skull with double the force because now the
skull is moving in the opposite direction as the brain.

Oops. I goofed. That should be:

Worse, your brain just keeps going forward, and hits the inside of
your skull with 4 times the energy because now the skull is moving in
the opposite direction as the brain effectively at twice the speed.
E=0.5mv^2
If the relative velocity is doubled, the energy is 4 times as large.


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

I'm deeply disappointed to hear that you don't approve of that elegant ruff which explodes into a helmet on impact.

Andre Jute

On Monday, May 4, 2015 at 4:10:21 AM UTC+1, Jeff Liebermann wrote:
On Sun, 3 May 2015 18:20:12 -0700 (PDT), Andre Jute
wrote:

This one would look good on a deranged cyclist like Franki-boy, and
keep him from doing harm to himself when he takes the lane, probably
by stopping him cycling altogether if not from weight then from embarrassment:

Try not to mix personalities with technology, which is much like
mixing oil and water. They don't mix well.

The ideal helmet is really a mental exercise in optimization. One
starts by defining a goal, which in this case is designing or at least
specifying a cycling helmet that would offer superior protection. One
then tries to produces a specification for such a helmet, that would
meet the primary goal, but also produce some serious compromises in
cost, size, weight, air resistance, appearance, manufacturability,
standards compliance, etc. Then, one takes the resultant abomination,
and balances these compromises, hopefully resulting in a sellable and
usable helmet. Some of the compromises may be different in the
various cycling market segments.

If I could have some useful additional safety for only a few ounces added
to my Bell Citi and Metro helmets, I would not begrudge the extra weight,
as those helmets do seem very light.. Where should the few ounces most
usefully be applied? Some kind of a HANS device?

I don't know. I would need statistics on the types of head and upper
body injuries incurred while wearing a helmet. If neck twisting is
the predominant culprit, some manner of collar to restrict rapid neck
twisting, possibly using a non-Newtonian fluid, might be useful. If
neck extension is statistically a problem worth solving, then a HANS
contrivance would be useful:
http://en.wikipedia.org/wiki/HANS_device
If back of neck injury, caused by the helmet digging into that area is
a problem, extra padding in that area would be useful. If cerebral
contusions are a problem, then anything that limits the peak velocity
of the head during impact will help, such as additional padding,
collapsible foam, corrugated crumple zones, and of course neck
support.

Doing all of these will result in something similar to the previously
mentioned "ideal" bicycle helmets, which is obvious overkill. So, one
must be selective, which requires statistics. Offhand, the crumple
zone and HANS contrivance seem the most worthwhile.

What about that neck ruff that blows up into a helmet in a milisecond
on sensing an impact that was mentioned here a few months ago? Air
has an admirable balance of absorption and displacement, or so
automobile suspension experts always reckon.

Notice that I never mentioned air bags. Pretend you've decided that
explosive driven automotive air bags are too dangers for the GUM
(great unwashed masses) and that pre-inflated air bags would be safer.
So, you design an automobile dashboard that is covered with inflated
air bags. The automobile would be undriveable and unsellable, but for
purposes of this discussion, those are not important. One day, your
automobile decides to swerve into a brick wall and your head hits the
pre-inflated air bag wall. What happens?

Well, first there's a big difference between an explosive inflated air
bag and a pre-inflated air bag. The first dissipated the energy of
your upper body slamming into the inflated bag by rapidly deflating
the bag. All the energy goes into emptying the bag from air. This
also has the added bonus of slowing the rate at which your upper body
approaches the (padded) dashboard.

However, the pre-inflated bags act more like springs than energy
absorbers. Your head and upper body hit the wall of bags and just
bounce back. All the energy you apply to the bag is returned to you
when you bounce back. Worse, your brain just keeps going forward, and
hits the inside of your skull with double the force because now the
skull is moving in the opposite direction as the brain.
http://en.wikipedia.org/wiki/Coup_contrecoup_injury

So, how to fix the problem? One way is to cover the dashboard with
water bags. When your face hits the wall of water bags, they explode,
taking the impact energy with the water. Your head goes forward, but
does not bounce back. However, the problem is that a water impact
tends to be rather hard. An improvement would be a non-Newtonian
fluid, such as corn starch. Your head still hits the starch bag hard,
but that causes redirects most of the energy perpendicular to the
point of impact. Once the initial impact pressure is relieved, the
starch becomes softer, decelerating your head slowly towards the
padded dashboard. The nice part is that there's no need for the
starch bag to burst in order to dissipate the collision energy.

Unfortunately, bicycles don't have dashboards and it's unlikely that
municipalities are going to pave the roads with corn starch bags. So,
we have to carry our air, water, or starch bags on our heads. I have
some ideas on how to make such a thing work, but not now. One thing
for sure, air bags won't work unless they provide a controlled
deflation on impact, which is difficult, expensive, and unlikely.

So, what will work? One thing is obvious from this rant is that
there's no such thing as a single helmet design that will protect
against every possible form of cycling accident. If someone tried to
make such a helmet, its size, weight, and cost would follow some of my
"ideal" helmet ideas. The best we can do is limit the protection for
specific types of injuries that the wearer is likely to encounter. For
racers, that would be high speed road and obstacle impact. For
commuters, it would side and rear impact by automobiles. For day
riders (like me) it would be falling over sideways after getting my
boot laces tangled in the crank. For BMX acrobats, landing head
first. For mountain bikers, rock penetration.

A big problem with designing the ultimate helmet is we have a fixation
on what a bicycle helmet should look like. Somehow, it still ends up
looking like a leather hair net.
https://www.google.com/search?q=bicycle+leather+hair+net&tbm=isch
It's going to take some effort to convince the public of a different
design. For example, one could build a reasonably functional bicycle
helmet from vinyl dipped chicken wire with ping pong balls between the
head and the wire. However, getting the GUM to accept that design
would be futile. Maybe an artistic cover might help:
http://www.thisblogrules.com/2010/07/bike-helmets-have-never-been-more-fun.html

Andre Jute
Fascination, I know...

More like machination.

--
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 Sun, 3 May 2015 23:27:23 -0700 (PDT), Andre Jute
wrote:

I'm deeply disappointed to hear that you don't approve of that
elegant ruff which explodes into a helmet on impact.
Andre Jute

It was too Elizabethan for my discerning taste. Besides, I was too
distracted by the gorgeous models:
https://www.google.com/search?q=ruff+collar&tbm=isch
https://www.google.com/search?q=bicycle+helmet+collar&tbm=isch
Yeah, pretty much the same collar.

Somewhere along the border line between safety and insanity are
devices that take control of your life and attempt to perform some
miraculous feat that one might not be able to do successfully were one
in conscious control. In other words, a pre-programmed device with
super human reaction time. As a motor vehicle driver, I have no
choice but to hand my future to the air bag designers. I'm not quite
ready to do the same with the bicycle helmet designers. I don't mind
getting killed or hurt if it's my fault or due to my limited reaction
time. I do mind when some device screws up and takes me with it.
Sorry, but wearing an air bag around my neck seems a bit risky, but
wearing one on the outside of a helmet might be acceptable.

Hmmm... how about we add some safety lighting to the helmet?
http://www.amazon.com/CoolGlow-LED-Viking-Helmet/dp/B008SCBWRM
I want one.

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

FIA ? no helmet standards eg SNELLFIA ? OR WHOM ?

'FOAM' permanently decompresses giving heat...

Bloomsburg Pa antique Susquehanna River town once McGee Carpet....dyestuffs into river popular....see Chesapeake toxicity...now Music school...had or has a 100 Miler. riders from Philly/Pittsburg/State College...excellent riding area rolling alluvial hills...covered bridges...log trucks....


https://www.google.com/maps/dir/Bloo...40.8668929!3e0

I picked the crash site with a loud cheer from the crowd...acknowledging their acumen..

and the crash brought the crashee down abt 15' away clear view...crack... lets see that would be a 1984 helmet.

helmet designs for the 99th percentile injury not effective...neither Swatch nor Checker

wedgie design ? four impact zone wedged by 8 foam wedges into a thin ejection material area ?

how's the tap water ? lakes drain yet ? golf course turn brown ? see any plant stress out in the field ?

I LIKE THE WEDGED FOAM idea for simplicity...but wonder abt layering foam densities as a questionable research area...among other concepts found in GooPatents.

when shopping or rather watching Lance and the TdF with Doporado Cyclist, we would see VENTING and then secondly plastic supports for VENTING

and mega buck insanity from Abe Giro et al

there were discussions of how a $300 helmet was better than my $20 late model....some rock throwing at the xxxxxxx wearing the $300 to Saturdays peloton

the neck ribbon held herbs and powders for disease prevention and odor coverup yours not mine or maybe both....also read a suggestion abt bugs and sexual proclivities....but that's due course...defesfinity in AJ's ballpark