My helmet saved me, and broke

[steveyo]

Hey all -

I was out in front of the house yesterday, practicing a bit of hopping on my KH29. After a UPD I mounted up again, and, as I'm sure everyone has experienced, I placed my second foot a bit too far back on the left pedal.

Now when this happens, I just unweight that foot and jiggle it forward a bit. Getting cocky, however, I tried to FLIP the pedal backward under my foot to reposition it. Too cocky.

I think what happened was I stopped the pedal, but anyway, I slammed to the ground MUCH faster than I ever have. Too fast to really get my hands up, and the thing that took the impact was the front, right edge of my bike helmet.

The helmet's foam got compressed and cracked up the middle. If I hadn't been wearing it, my forehead/nose/right cheekbone would have smashed on the pavement.

As it was, the tip of my nose barely touched the road, and I walked away with a bruised thumb and a scraped knee.

I used to wear the helmet just as an example to my kids and other neighborhood kids. From now on I'll be wearing one and telling the story of how a helmet saved my face and head.

[Brian MacKenzie]

Wow, good work.

Argue with that!

[UNIquelyCanadian]

Glad to hear you are ok. Good thing for the helmet; I'll continue wearing mine but now with a unicycling story to back up it necessity. Thanks.

I submit that on or about Sat, 27 Aug 2005 08:28:21 -0500, the person
known to the court as "steveyo"
<steveyo@NoEmail.Message.Poster.at.Unicyclist.com> made a statement
(<steveyo.1ufdd0@NoEmail.Message.Poster.at.Unicyclist.com> in Your
Honour's bundle) to the following effect:

>The helmet's foam got compressed and cracked up the middle.

In other words, it failed. If it had done this on test it would have
failed the test. You do know that polystyrene foam absorbs very
little energy in brittle failure, don't you?

It never fails to amaze me the number of people who hold up helmets
which have conspicuously failed to work as designed as some kind of
example of how wonderful they are!

Strangely, the number of "helmet saved my life" anecdotes vastly
outweighs the number of people who have ever suffered serious head
injury...

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken

[Mikefule]

Originally posted by Just zis Guy, you know?

Strangely, the number of "helmet saved my life" anecdotes vastly
outweighs the number of people who have ever suffered serious head injury... (Mikefule adds: presumably, in a unicycle accident?)

It also vastly outweighs the number of "helmet made things worse when I banged my head" anecdotes.

If the helmet was damaged and the head wasn't, then it is reasonable to assume that in the absence of the helmet, the head would have been damaged. That has to be a result.

No one has to wear a helmet, so why some people argue so strongly against their use mystifies me.

(Arguing against compulsory helmet use is a valid stance to adopt.)

[U-Turn]

Originally posted by Just zis Guy, you know?
I submit that on or about Sat, 27 Aug 2005 08:28:21 -0500, the person
known to the court as "steveyo"
<steveyo@NoEmail.Message.Poster.at.Unicyclist.com> made a statement
(<steveyo.1ufdd0@NoEmail.Message.Poster.at.Unicyclist.com> in Your
Honour's bundle) to the following effect:

>The helmet's foam got compressed and cracked up the middle.

In other words, it failed. If it had done this on test it would have
failed the test. You do know that polystyrene foam absorbs very
little energy in brittle failure, don't you?

It never fails to amaze me the number of people who hold up helmets
which have conspicuously failed to work as designed as some kind of
example of how wonderful they are!

Strangely, the number of "helmet saved my life" anecdotes vastly
outweighs the number of people who have ever suffered serious head
injury...

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken

This helmet did its job by absorbing the impact and saving Steve from serious injury, as it was designed to do. This type of helmet (assuming it is the normal bicycle helmet) is designed to perform just as it did; and is for one-impact use only. It is supposed to crack! Steve may be able to get a free or discounted replacement through the shop where he bought it or through the manufacturer, since some of them have programs for just that purpose.

[steveyo]

Originally posted by Just zis Guy, you know?
I submit that on or about Sat, 27 Aug 2005 08:28:21 -0500, the person
known to the court as "steveyo"
<steveyo@NoEmail.Message.Poster.at.Unicyclist.com> made a statement

>The helmet's foam got compressed and cracked up the middle.

In other words, it failed. If it had done this on test it would have failed the test. You do know that polystyrene foam absorbs very little energy in brittle failure, don't you?

Guy
--

With all due respect, and perhaps more so, you're wrong.

Bicycle helmets are designed to protect one's head from a SINGLE impact, and it did. That's a success, not a failure.

It absorbed a huge amount of energy, not "very little". If it had absorbed "very little" energy, I'd be in the hospital right now awaiting facial surgery, or worse.

"Just zis Guy, you know?" <uce@ftc.gov> wrote:


[foolishness elided]

I am going to forego my usual polity and circumlocution, getting
straight to the point.

Hey, you bicycling anti-helmet fanatic. Please to keep your irrational
parascientific foaming at the mouth antihelmet ravings over on
rec.bicycles.misc where they are appreciated.

I am serious about this. Your audience here includes about 50X more
kids, earnest impressionable youngsters under 18 -- under 14 even, than
r.b.m. It is unconscionable for you to come over here and spew your
nonsense. You are a menace.

This is not a debate, and i'm not going to get into an
rec.bicycles.misc-style 500-post point-counterpoint about it. Just shut
up and Leave.

Thamk ewe sew mutch.

Kids, ignore this guy, he is clazy in the head. Brave Sir Stupid says
so, so it must be true. Wear your helmets.



..max

aka
betatron@earthlink.net "what doe THIS button do?!"
betatron@gmail.com
maxwell@fnal.gov

On Sat, 27 Aug 2005 14:46:47 +0100, Just zis Guy, you know? <uce@ftc.gov> wrote:
>
> It never fails to amaze me the number of people who hold up helmets
> which have conspicuously failed to work as designed as some kind of
> example of how wonderful they are!

Keep calm Guy - he only does it to annoy, he knows that it displeases
(and if that's not teh case, he's not going to understand).

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

[Carey]

Hear, hear!!

Wear your helmet--and your wrist guards!!

I just got my new Harbinger wrist protectors so I won't have to wear the brace they gave me when I fell off and landed on my wrist without any protection. A lesson I never intend to learn again--I will never ride without both a helmet and wrist guards in the future, for any reason.
And, I don't even try some of the crazy stuff you guys are doing. Take care of yourself so you can continue to stretch the limits of unicycling!

Carey

On Sat, 27 Aug, Brave Sir Stupid <betatron@earthlink.net> wrote:
>
> your irrational parascientific foaming at the mouth

followed by ...

> Brave Sir Stupid says so, so it must be true.

I don't really think there's anything more to be said. Anyone dumb
enough not to draw the appropriate conclusion from this isn't going to
be convinced by mere facts, let alone truth.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

I submit that on or about Sat, 27 Aug 2005 10:28:27 -0500, the person
known to the court as Brave Sir Stupid <betatron@earthlink.net> made a
statement (<deq0qh$3vb$1@ftupet.com> in Your Honour's bundle) to the
following effect:

>Hey, you bicycling anti-helmet fanatic. Please to keep your irrational
>parascientific foaming at the mouth antihelmet ravings over on
>rec.bicycles.misc where they are appreciated.

Anti-helmet fanatic, eh? That would be why most of the pictures on my
website show me wearing one, then. Oh, wait...

You will also find, parked next to my Brompton and my tandem in the
kitchen, one 24" unicycle.

Please feel free to stick to reality any time you like. And reality,
in this case, means a broken helmet is a failed helmet, and that is as
much an advert for the product as any other failed, broken product.
For unicycling I recommend a hard-shell lid of the sort usually worn
by BMXers. Bicycle helmets are very weak, and modern fitting systems
mean they offer little protection at the back of the head.

Failing that an old-style Bell Biker would probably do. If you can
find one.

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken

I submit that on or about Sat, 27 Aug 2005 09:34:44 -0500, the person
known to the court as "Mikefule"
<Mikefule@NoEmail.Message.Poster.at.Unicyclist.com> made a statement
(<Mikefule.1ufgdd@NoEmail.Message.Poster.at.Unicyclist.com> in Your
Honour's bundle) to the following effect:

>> Strangely, the number of "helmet saved my life" anecdotes vastly
>> outweighs the number of people who have ever suffered serious head
>> injury... (Mikefule adds: presumably, in a unicycle accident?)

>It also vastly outweighs the number of "helmet made things worse when I
>banged my head" anecdotes.

Yes. In those cases the translation of linear into rotational
acceleration usually precludes future involvement in Usenet...

>If the helmet was damaged and the head wasn't, then it is reasonable to
>assume that in the absence of the helmet, the head would have been
>damaged. That has to be a result.

No, it is not. If the helmet broke, it is reasonable to presume that
it broke, and nothing more. This is *not* a good advert for helmets!
For unicycling I would recommend a good quality hard-shell BMX style
lid, which gives decent coverage to the back of the head.

>No one has to wear a helmet, so why some people argue so strongly
>against their use mystifies me.

Me too. I don't do that, of course - I merely argue that those who
advocate their use should base their advocacy on facts, rather than
hyperbole based on misunderstanding how they are supposed to work, and
their failure modes.

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken

I submit that on or about Sat, 27 Aug 2005 10:03:01 -0500, the person
known to the court as "U-Turn"
<U-Turn@NoEmail.Message.Poster.at.Unicyclist.com> made a statement
(<U-Turn.1ufhj3@NoEmail.Message.Poster.at.Unicyclist.com> in Your
Honour's bundle) to the following effect:

> This helmet did its job by absorbing the impact and saving Steve from
>serious injury, as it was designed to do.

No, it did not do its job. It fractured. They are not supposed to do
that. Polystyrene foam absorbs little or no energy in brittle
failure; the failure is an indication that it was the wrong kind of
helmet for the job. A hard-shell would probably have worked as
designed (i.e. not broken).

>It is supposed to crack!

Absolutely not. The helmet is supposed to maintain its structural
integrity. It is supposed to *crush* without cracking. Read the
standards and test specs if you don't believe me.

I have this on the authority of Brian Walker, the MD of Head
Protection Evaluations, who tests most of the helmets which come into
the UK.

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken

I submit that on or about Sat, 27 Aug 2005 10:06:59 -0500, the person
known to the court as "steveyo"
<steveyo@NoEmail.Message.Poster.at.Unicyclist.com> made a statement
(<steveyo.1ufhrd@NoEmail.Message.Poster.at.Unicyclist.com> in Your
Honour's bundle) to the following effect:

>With all due respect, and perhaps more so, you're wrong.

Please point out where in the standards it says they are supposed to
fracture.

>Bicycle helmets are designed to protect one's head from a SINGLE impact,
>and it did. That's a success, not a failure.

They are designed to do so without breaking.

>It absorbed a huge amount of energy, not "very little". If it had
>absorbed "very little" energy, I'd be in the hospital right now awaiting
>facial surgery, or worse.

Here is what is supposed to happen:

The foam liner is supposed to crush, reducing the linear acceleration
of the head. There are standards for the amount of energy they are
supposed to absorb without breaking, and these are equivalent to a
fall from about 1.5m onto a flat surface, discounting the weight of
the body.

There are two main failure modes: one is that the foam is compressed
beyond its capacity, in which case it has absorbed as much energy as
it can, and any further energy is transferred to the head. The other
is that it breaks, in which case an unknown proportion of the design
energy is absorbed beforehand. Think here about a sheet of glass. You
can put something quite heavy on a sheet of glass and it is fine, but
drop a much lighter weight from even a few inches and the glass
shatters. If the energy rating of the foam is exceeded, it can fail
almost instantaneously. You can verify this for yourself using some
blocks cut form computer packaging (the same stuff, essentially).

So: we do not actually know what proportion of the design energy was
absorbed before the helmet broke. Some, sure. But not as much as it
was supposed to. It did not work as designed.

In my view the chances of falling are sufficiently high with
unicycling, and the direction of falling so unpredictable, that a
standard bicycle helmet is not a good choice for yiking. I use (when
I do) an old Bell lid which covers the back of my head much better
than my modern bike helmet. BMX helmets are probably the best choice
for unicyclists.

Sorry, I'm really not trying to be contentious here (honest!); it's
just that "my broken helmet worked like a dream" is a bit of a red rag
for me. I don't think we do ourselves any favours by deluding
ourselves on these matters. When you replace the lid, I strongly
suggest a hard shell, preferably Snell certified.

And - I am ashamed to say - I forgot to say I'm glad you;re fine. I
am, truly. I have had a couple of moderately serious head and face
injuries in my life, and they are no fun.

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

"To every complex problem there is a solution which is
simple, neat and wrong" - HL Mencken