Helmets - mean time betweef failures

On 2006-01-05, Theo Bekkers (aka Bruce)
was almost, but not quite, entirely unlike tea:
TimC wrote:
Theo Bekkers wrote
Rayc wrote:

If your Betamax recorder still works then who am I to argue.

I was never stupid enough to buy one.

Stupid? What was stupid about betamax?

Nothing stupid about the system. It actually is far superior to VHS. It was
Sony's attempt to keep the technology to themselves and make a huge profit

I wasn't aware of the history, only the bit about it being better than
VHS. Makes all the more sense now. Consumers aren't necessarily
stupid, afterall.

that was the problem. Much like Apple really. If Apple had licenced their
computer technology we'd all be using Apple clones now instead of IBM
clones.

And dear ghod, I'm glad weren't not using apple clones now. Although,
I suspect, if I stay in astronomy, I'm going to end up having to help
all the mac newbies out on their mac systems because it is only half
arsed unix and keeps breaking in subtle ways. Dunno why macs are so
popular, when we have a perfectly good unix system. Probably the same
reason tcsh is still popular around here.

--
TimC
Modus Ponens in action:
- Nothing is better than world peace.
- A turkey sandwich is better than nothing.
== Ergo, a turkey sandwich is better than world peace. --unknown

On Tue, 03 Jan 2006 08:20:41 GMT, "Andrew Price"
wrote in aus.bicycle:

Big chunk of styrofoam fell out of the Limar helmet on the way home from
work tonight, right where the strap attaches at the back.

5 years constant use, a few minor scrapes (there was that low tree branch
once as I recall) so I guess I can't complain - but I really think it was
the rash threat to wash it because it was getting a bit pongy in the heat
that caused it to give up the ghost.

Umm. I have had three helmets in something like 20 years (yes I wore
one before it was required by law) and the only failure has been on
an early model where the foam strip stuck to the inside of the
polysyrene started to crumble into a powder. This was long after I
stopped using it. As far as I can see my current one, aTwister ($25),
is showing no deteriation and I think it is about 7 years old perhaps
a bit more.

Anyway when you think about it even if you did have to replace it
every five years $5 a year is less than what you spend on tyres in
that time.


Regards
Prickles

This message only uses recycled electrons

Bleve wrote:
Theo Bekkers wrote:

TimC wrote:

Theo Bekkers wrote

Rayc wrote:

If your Betamax recorder still works then who am I to argue.

I was never stupid enough to buy one.

Stupid? What was stupid about betamax?

Nothing stupid about the system. It actually is far superior to VHS. It was
Sony's attempt to keep the technology to themselves and make a huge profit
that was the problem. Much like Apple really. If Apple had licenced their
computer technology we'd all be using Apple clones now instead of IBM
clones.


a lot of us *are* using UNIX

Indeed

On Wed, 04 Jan 2006 07:48:36 +0000, Stuart Lamble wrote:



I'm not saying that they *are* protective -- just that it's something of
a non sequitur to say "bruise to the head + massive damage to the helmet
= helmet isn't protective." To make that call, you need two identical
impacts on two heads that differ only by the presence of the helmet,
followed by a comparison of the damage to the two heads.

Or in other words: I am neither defending nor attacking the use of
helmets. I am merely attacking the logical non-argument used by Peter.

My personal take: I am required by law to wear a helmet. Therefore, I
wear a helmet. Unless and until that law is repealed or changed, I see
no point in arguing the point further.

There are other alternatives, including emigrating to a country where one
is not required to wear a helmet. (at last count 193 of them).
However, uncontrolled personal experience is everything -- *sigh*
Many helmet "wars" may be at least partially defused if we realised that
those against mandatory helmet laws are not necessarily against the
wearing of helmets.

Peter


--
No Microsoft involved. Certified virus free --

On Thu, 05 Jan 2006 12:39:11 +0800, Theo Bekkers wrote:

That equates to hitting something solid at about 26 km/h. Hmmmm.

Edge on - I wouldn't want to catch the corner of a stopped truck at
26km/h. The helmet was still recognisable, but there was a *big* crack in
it. Remember this helmet had already had a few big hits, and there was
noticeable denting of the foam.

Then again I've got a lovely bruise on my hip from a virtually stopped
front wheel slide (off the side of a rock, which I then landed on) to say
that speed isn't everything.

--
Dave Hughes |
"I've found that nurturing one's Zen nature is vital to dealing with
technology. Violence is pretty damn useful too" - Lionel Lauer

Theo Bekkers wrote:

Umm, it has the same standards sticker on it as this years helmet crop, so
how is it sub-standard?

I'm sure that the helmet was standards compliant when manufactured, but
what about now?
The general wear and tear of general use and the exposure to UV and
contaminates surely affect the shock absorbation ability of that
helmet.

Thats the point of this thread, asking the acceptable working life of a
helmet. Having a helmet that can absorb as much impact as possible, is
what I would like to have , and am quite happy to ensure that I have
this on my bonce.


The idea that a 19yr old helmet, is still good to wear and will protect
you is not something that I want to test on me or my loved ones.

Mine is a hard shell (as they all were then). I would think the current
"less shell" models would not give me better or equal protection.

Now arguement there, the hard shell helmet would offer more abrasion
resistance, but its the foam inside that absorbs the impact shock. This
abillty of the said 19yr old foam still absorbing the shock to the same
extent and ability is the arguement.

Newer helmets generally fit alot better. Thats where the money
generally goes for the better helmets - R&D.

Mine fitted very well when I bought it (It was a very expensive helmet at
the time) and my head has not changed shape since.

Theo
Please try to include at least a little of who and what you're replying to
so that I, and others, can follow the conversation.
Sorry i thought I waas (mostly)

Rayc wrote -

Thats the point of this thread, asking the acceptable working life of a
helmet. Having a helmet that can absorb as much impact as possible, is
what I would like to have , and am quite happy to ensure that I have
this on my bonce.

As the OP of this thread I report having gone and bought a new Limar because
their shape still fits my head really well (ymm vary) and the lbs guy and I
did a bit of an autopsy on the dead one (slow day in t' shop). Things
observed -

1. Strap attachment to helmet is better - attachment no longer relies on
adhesion of a pad to soft polystyrene, which is where the original failed.
2. Suspension of head from helmet is better - yes there are more and larger
ventilation holes but there is also a slight gap where the soft mesh liner
keeps the polystyrene seperated from your head - improves ventilation and
comfort more than just the old stick in pads the old one had.
3. When we pulled the old one apart the polystyrene really had deteriorated
badly, especially where the straps were attached to it - crumbled with not
much applied force in the weakest bits - was clearly past its use by date.
Probably worth giving the helmet a bit of an inspection every so often,
rather than assuming continued integrity as a given.
4. New ones do seem to offer a bit more protection behind the ear and come
down lower in that region.
5. Liked the quick adjustment wheel at the back - I tend to wear a head band
to warm the ears in winter and its going to be easier to adjust the helmet
for that.
6. Looks dorkier than the old one, but then again you aren't going to see
cool models on the catwalk featuring helmets anytime soon, unless the OH&S
people really get out of control.
7. Limar offer a 3 year replacement for half original price if you do have a
gravity assisted rapid dismount and use the item for its intended purpose (I
think other manufactrurers may do something similar) - seemed a fair deal.
8. Less expensive Giro lookalikes (called Tec I think) are starting to
appear for about 1/3 the price if the top of the line jobs and seemed to
weigh much the same - no info on longevity of the knock offs yet available -
had the relevant AS approved sticker attached to them for what that's worth.

Have no wish to ever enter the never ending h*lm*t effectiveness debate -
its just if you have to by law have one, its good to know they seem to be
trying to improve them.

But I suspect the effective lifespan of the current ones, with constant use,
is relatively short.

best, Andrew

Andrew Price wrote:

As the OP of this thread I report having gone and bought a new Limar ......
and the lbs guy and I did a bit of an autopsy on the dead one ....

3. When we pulled the old one apart the polystyrene really had deteriorated
badly, especially where the straps were attached to it - crumbled with not
much applied force in the weakest bits - was clearly past its use by date.
Probably worth giving the helmet a bit of an inspection every so often,
rather than assuming continued integrity as a given.

Good to see you had a good look over the old one and was more than
happy with your decision to get a new one based upon close inspection
(albeit with destruction of said helmet)

7. Limar offer a 3 year replacement for half original price if you do have a
gravity assisted rapid dismount and use the item for its intended purpose (I
think other manufactrurers may do something similar) - seemed a fair deal.

they're not all that bad really, there's a cost involved but not the
full whack ($ rrp)

8. Less expensive Giro lookalikes (called Tec I think) are starting to
appear for about 1/3 the price if the top of the line jobs and seemed to
weigh much the same - no info on longevity of the knock offs yet available -
had the relevant AS approved sticker attached to them for what that's worth.

Trickle down !



But I suspect the effective lifespan of the current ones, with constant use,
is relatively short.

best of luck with keeping this one for a while!

On 2006-01-05, Rayc (aka Bruce)
was almost, but not quite, entirely unlike tea:
Andrew Price wrote:
7. Limar offer a 3 year replacement for half original price if you do have a
gravity assisted rapid dismount and use the item for its intended purpose (I
think other manufactrurers may do something similar) - seemed a fair deal.

they're not all that bad really, there's a cost involved but not the
full whack ($ rrp)

Damn. I've replaced two helmets over the last few years without this
knowledge.

--
TimC
"A distributed system is one in which I cannot get something done
because a machine I've never heard of is down." -- Leslie Lamport

Rayc wrote:

I agree, except for the point that -that helmet used during that
period of twenty years, would surely have suffered some degredation,
UV exposure, falling on the ground when a bike falls over, body oil
contamination etc. So how or by what method can we test or be given
assurances that the 20yr old helmet can still absorb the same impact

According to Zebee's post on motorcycle helmets, all the old ones passed the
tests. No, you don't have any assurances except that a number of units
tested passed the test criteria. This may or may not have any relevance to
real life situations. a lot of data collected over the last 20 years say
that helmet wearing has little or no effect on fatality rates of bicyclists.

That is my point, helmet manufacturers have given us a expected life
of the helmets ( up to 5yrs) they have supplied reasons (UV exposure,
contamination etc) and I believe that these are acceptable constraint
for a helmet's working life.

You think helmet manufacturers are the best people to judge expected life? I
think this is more likely a "What the market will bear" judgement.

So my train of thought goes........
a helmet can only last so long....... max of 5yrs - less with uv
Exposure, contamination,etc................. I want maximum shock
absorbtion... so replace helmet every 2-3 years.

As I said, I'm still wearing my old Bell. OTOH my motorcycle helmet is only
about 6 or 7 years old. :-)

You can never know when your going to have an accident, so hoping for
best odds, I would want to have the best protection.

Best to stay in bed then.

Theo