Helmets

On Wed, 06 Jul 2005 16:03:33 -0400, wrote:

"yk" wrote:

The price range from $10 - $200. What are the differences ? Are
expensive helmets safer or more aero-dynamically designed ? What to look
for besides fit and color ? TIA

Fit is high on the list. If you don't like it, you won't wear it, it
won't be there when, not if, you need it. Christopher Reeves became a
paraplegic from a fall from a horse. Yes he was higher but dirt is
softer than asphalt.

Ventillation is up there also.

Wear your helmet, smiling beats drooling,

Wes

Dear Wes,

Without arguing about the merits of helmets . . .

Reeves suffered a broken neck, not a head injury.

He became a quadriplegic, not a paraplegic.

And he was wearing a helmet.

Carl Fogel

yk wrote:
The price range from $10 - $200. What are the differences ? Are
expensive helmets safer or more aero-dynamically designed ? What to look
for besides fit and color ? TIA


As far as I know, all helmets sold in the US meet basic safety standards
defined by the consumer protection agency. I believe the standard is Z90
(IIRC), and the helmet liner is marked accordingly. Moreover there used
to be a more stringent standard used by the SNELL institute. Helmets
with SNELL ratings used to be more safe (for penetration) than helmets
that just met the Consumer protection standards. I am not sure if SNELL
still exists, but I would suggest that you look for a helmet that has a
SNELL rating if you are looking for the ultimate in safety. I would
appreciate comments from anyone who knows the current situation, because
I am not sure of it.

HTH,
Ernie

E Willson wrote:
yk wrote:

The price range from $10 - $200. What are the differences ? Are
expensive helmets safer or more aero-dynamically designed ? What to
look
for besides fit and color ? TIA


As far as I know, all helmets sold in the US meet basic safety standards
defined by the consumer protection agency. I believe the standard is Z90
(IIRC), and the helmet liner is marked accordingly. Moreover there used
to be a more stringent standard used by the SNELL institute. Helmets
with SNELL ratings used to be more safe (for penetration) than helmets
that just met the Consumer protection standards. I am not sure if SNELL
still exists, but I would suggest that you look for a helmet that has a
SNELL rating if you are looking for the ultimate in safety. I would
appreciate comments from anyone who knows the current situation, because
I am not sure of it.

I grazed google past this topic about a month or so ago, and I was left
with the impression that SNELL does not exist for bicycle helmets
(anymore). It's pretty much a motorcycle helmet thing.

To the original poster, since all helmets in the US pass the same test,
the only real difference is ventilation and appearance.

-eric

mark wrote:

Am I missing something, or is a cyclist hit from behind
by a car going to get accelerated rather abruptly to the car's speed at the
time of impact, regardless of closing speed?

40 mph car rear-ending a 20 mph cyclist has a closing speed of 20 mph.

40 mph car hitting the front of a 20 mph cyclist hits with closing
speed of 60 mph. I think I'd rather be accelerated 20 mph rather than
60 mph.

RFM

It is the impact that counts. The net effect of being hit by a 40 mph car,
when you are riding in the same direction at 20 mph, is like standing still
and being hit by a 20 mph car. Yes, you will be accerelated plus 20 mph in
either case but at a much slower rate.

The other case you get hit by a 60 mph car, and then accelerated to 40 mph.
BIG difference.

"Fritz M" wrote in message
ups.com...
mark wrote:

Am I missing something, or is a cyclist hit from behind
by a car going to get accelerated rather abruptly to the car's speed at
the
time of impact, regardless of closing speed?

40 mph car rear-ending a 20 mph cyclist has a closing speed of 20 mph.

40 mph car hitting the front of a 20 mph cyclist hits with closing
speed of 60 mph. I think I'd rather be accelerated 20 mph rather than
60 mph.

RFM

Eric Hill wrote:
E Willson wrote:
I am not sure if SNELL
still exists, but I would suggest that you look for a helmet that has a
SNELL rating if you are looking for the ultimate in safety. I would
appreciate comments from anyone who knows the current situation, because
I am not sure of it.

The Snell rating still exists, in that any manufacturer who has a
helmet that meets Snell requirements, and who wants to pay to have it
certified by Snell, can do so. However, manufacturers seem to have
decided en masse that it's not worth paying for that certification.
The US law requires CPSC certification, and they're happy enough with
that.

And I wouldn't call Snell " the ultimate in safety." Snell is just
slightly more stringent than CPSC. (CPSC requires a 2 meter drop;
Snell a 2.2 meter drop.) The impact speeds are very nearly equal.
Neither test has the mass of a body attached to the headform. IOW, the
helmets are certified to protect a decapitated head hitting something
at 14 mph. Hitting at 16 mph is beyond what they're designed for.
Hitting with your body still attached to your head is also likely to
overpower the helmet.

Incidentally, I think this is why Snell certification isn't popular.
If a manufacturer claimed "Ours is more protective! We're _Snell_
certified!!" some consumers would ask "What's the difference?"

The answer would have to include a description of the laughably low
certification; and once that was given, the jig would be up. Consumers
and legislators would realize how worthless the things are.


I grazed google past this topic about a month or so ago, and I was left
with the impression that SNELL does not exist for bicycle helmets
(anymore). It's pretty much a motorcycle helmet thing.

To the original poster, since all helmets in the US pass the same test,
the only real difference is ventilation and appearance.

Not so. As others have pointed out, more expensive helmets tend to be
lighter and have better ventilation. That makes them generally less
uncomfortable to wear. But it also makes them less protective. Much
of the expense in a pricey helmet comes from the extensive computer
modeling and testing to get them to be as light and "holey" as
possible, but JUST BARELY pass the standards test.

The cheaper ones have more margin of protection. They leave in more
styrofoam and cut fewer holes so they can be sure it will pass the test
without re-designing.

So when you pay more, you get better ventilation, but you get less
protection. You also tend to get something that looks more like a
psychedelic squid wrapped around your head. But there's no accounting
for fashion!

- Frank Krygowski

Eric Hill wrote:

E Willson wrote:

I am not sure if SNELL
still exists, but I would suggest that you look for a helmet that has a
SNELL rating if you are looking for the ultimate in safety. I would
appreciate comments from anyone who knows the current situation, because
I am not sure of it.


The Snell rating still exists, in that any manufacturer who has a
helmet that meets Snell requirements, and who wants to pay to have it
certified by Snell, can do so. However, manufacturers seem to have
decided en masse that it's not worth paying for that certification.
The US law requires CPSC certification, and they're happy enough with
that.

And I wouldn't call Snell " the ultimate in safety." Snell is just
slightly more stringent than CPSC. (CPSC requires a 2 meter drop;
Snell a 2.2 meter drop.) The impact speeds are very nearly equal.
Neither test has the mass of a body attached to the headform. IOW, the
helmets are certified to protect a decapitated head hitting something
at 14 mph. Hitting at 16 mph is beyond what they're designed for.
Hitting with your body still attached to your head is also likely to
overpower the helmet.

Incidentally, I think this is why Snell certification isn't popular.
If a manufacturer claimed "Ours is more protective! We're _Snell_
certified!!" some consumers would ask "What's the difference?"

The answer would have to include a description of the laughably low
certification; and once that was given, the jig would be up. Consumers
and legislators would realize how worthless the things are.


I grazed google past this topic about a month or so ago, and I was left
with the impression that SNELL does not exist for bicycle helmets
(anymore). It's pretty much a motorcycle helmet thing.

To the original poster, since all helmets in the US pass the same test,
the only real difference is ventilation and appearance.


Not so. As others have pointed out, more expensive helmets tend to be
lighter and have better ventilation. That makes them generally less
uncomfortable to wear. But it also makes them less protective. Much
of the expense in a pricey helmet comes from the extensive computer
modeling and testing to get them to be as light and "holey" as
possible, but JUST BARELY pass the standards test.

The cheaper ones have more margin of protection. They leave in more
styrofoam and cut fewer holes so they can be sure it will pass the test
without re-designing.

So when you pay more, you get better ventilation, but you get less
protection. You also tend to get something that looks more like a
psychedelic squid wrapped around your head. But there's no accounting
for fashion!

- Frank Krygowski


To continue the thread

Thanks for the several replys

As you say , the SNELL rating is basically a motorcycle thing which has
been applied to bicycle gear. Based on your comments I believe that the
impact performance of a CPSC helmet and a SNELL certified helmet is
about the same. IIRC the SNELL certification came about because a
motorcycle rider named Snell was killed by a sharp metal object that
penetrated his helmet, killing him. The helmet he was wearing was
adequate for impact resistance. As I remember it, the original intention
of the SNELL rating was to improve the penetration performance of
helmets. Based on what has been said here, I'd have to assume that if a
helmet carried a SNELL certification it would be as good (or better) in
impact as a CPSC rated helmet, and it would be more protective against
penetation type objects. Does this sound correct?

Comments?

Regards,
Ernie Willson

E Willson wrote:


To continue the thread

Thanks for the several replys

As you say , the SNELL rating is basically a motorcycle thing which has
been applied to bicycle gear. Based on your comments I believe that the
impact performance of a CPSC helmet and a SNELL certified helmet is
about the same. IIRC the SNELL certification came about because a
motorcycle rider named Snell was killed by a sharp metal object that
penetrated his helmet, killing him. The helmet he was wearing was
adequate for impact resistance. As I remember it, the original intention
of the SNELL rating was to improve the penetration performance of
helmets. Based on what has been said here, I'd have to assume that if a
helmet carried a SNELL certification it would be as good (or better) in
impact as a CPSC rated helmet, and it would be more protective against
penetation type objects. Does this sound correct?

Well, not really. Snell was an auto racer, and the fatality didn't
involve penetration, AFAIK.

From the Snell Memorial Foundation website:

"William "Pete" Snell died in 1956 because his then state of the art
helmet lacked the protective capacity to see him through what was
termed a survivable accident. Pete Snell's helmet represented an
intuitive solution for impact protection. After Snell's death, Dr.
George Snively demonstrated that human intuition is not a reliable
guide to understanding crash impact, particularly in the millisecond
time domains in which crash impact occurs.

Snively discovered that most injuries of helmeted people occurred
because the liner had reached full compression, that is, the helmet had
used up all its protective capacity, before the impact was over.
Helmets were too thin and far too soft.

Snively studied auto racing accidents and compared injury versus helmet
compression in real world impacts to peak acceleration versus helmet
compression in laboratory tests. He concluded that young healthy men
could expect to withstand head impacts corresponding to lab tests
incurring from 400 to 600 G's. Since tolerances vary among people and
are likely to vary with age, Snively set Snell test criteria at about
300 G's.

Snively then set up the first of the Snell helmet standards..."

Also from that website:

" William "Pete" Snell was an amateur auto racer. He died needlessly in
a racing event in 1956 when his then state-of- the-art helmet utterly
failed to protect him."


What's interesting to me is that there have been many deaths of
helmeted cyclists, including cyclists wearing Snell-certified helmets!
One could say that each of these "died needlessly when his then
state-of-the-art helmet utterly failed to protect him."

IOW, one could use the same logic to call for a new Memorial
Foundation!


Seriously, the Snell Memorial Foundation has certainly improved helmet
science. I just wish they'd drop the rabid promotion of helmets for
activities that are already more than reasonably safe. Like cycling,
of course.

- Frank Krygowski

Eric Hill wrote:

I was left with the impression that SNELL does not exist for bicycle helmets

Not quite. See the link below for a discussion of the various
standards.
http://www.bhsi.org/standard.htm

Art Harris

wrote:

Dear Wes,

Without arguing about the merits of helmets . . .

Reeves suffered a broken neck, not a head injury.

He became a quadriplegic, not a paraplegic.

And he was wearing a helmet.

Carl Fogel

I grant you that. He might have made it to dead sooner w/o the
helment. I don't remember anyone blaming his broken neck on the
helmet.

There are times when being thrown from a car beats riding it all the
way. Odds favor seatbelts.

I belive in self determination. Darwin isn't operating all that well
in our society.

Wes

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