Helmets - mean time betweef failures

A bike helmet must meet the Australian Standards no matter how old it
is. This implies that the latest helmet shall meet the same minimum
standard as the Rosebank Stackhat of 20 years ago. So for impact
protection they both provide similar protection. (remember here that
one is a soft shell and the other a hard shell). The main difference
with a modern helmet is that it is a lot lighter and has better
airflow. This also goes for the bottom to top of the range.

Looking at the foam padding of them, the polystyrene is pretty much the
same in both and that is what does all the work. The shell merely stops
the foam from being ground away as your head runs along the ground.

Provided the Polystyrene is in good condition (i have always checked
polystyrene by seeing if it is going chalky) there should be no reason
why i would stop using it apart from daggy looks. If it has been in an
impact of any kind, i'd throw it away and spend my money on a new
helmet as this one has done its job and will be compromised in case of
a future accident.


--
smartie

Peter Keller wrote:

On Wed, 04 Jan 2006 11:18:54 +1000, Tamyka Bell wrote:


I am not sure if an "inspection" service is useful at all. The propaganda
is that after any knock, however minor, the helmet should be replaced as
damage to it may be invisible but still real, thus lessening greatly
whatever protective properties it had.

Peter

I found a miniature compression spot on a helmet after I'd stacked it...
which happened to correspond to a small bruise on my head, so I decided
to check it out. When we peeled back the plastic, we found a massive
crack that was not at all visible from outside. The bike shop was very
responsible and insisted I smash the crap out of the helmet so that no
one would take it out of the bin and try to use it. The thought of that
scared me - I am always amazed when people sell second hand bikes with a
helmet included.

Tam

What? A bump causing a small bruise on your head caused that amount of
massive damage to the helmet?
My!! Aren't they protective!!

I really hope that was sarcasm.

Ever seen the demonstration where someone lies on a bed of nails, with a
bessa block on their abdomen, and someone else smashes the brick with a
sledgehammer.

Speaking from experience - if the brick doesn't break, it bloody hurts.

Tam

It amazes me that people actually argue about the protection offered by
a helmet.


From my experience a helmet does a hell of alot.

1. Had a minor accident (sitting on my bike out the front of my parents
house and was knocked over by a friend stopping beside me) while not
wearing a helmet. It resulted in my head hitting a gutter on the left
hand side resulting in a fractured skull and a week in hospital for my
troubles.
2. Broke a rear hub axel while out of the saddle leaving a friends
driveway which resulted in the chain slipping and me going over the
bars head first into the ground. Resulted in a dented and cracked
helmet and a snapped collarbone. But I was able to get up and walk
home.
3. Crashed face first in a DH race into rocks which resulted in a
broken finger, dislocated knee and alot of skin loss. Cracked the
fibreglass in the mouthpiece of my full face helmet. Was able to get
back on my bike and roll to the finish line.
4. Crashed in a fast section of a DH race which resulted in a dent and
cracking on the side of a full face helmet and a broken collar bone.
Was able to walk to the bottom of the track.
5. Front wheel tapped a 6m double in a quad compressor mtb race at 40+
kph which resulted in me landing on my head from a long way up. Helmet
was broken in 7 places and I also had a broken hand. Was able to walk
up to the first aid tent for treatment. (Lotte drove me home).
6. I always wore a helmet in skateparks on my bike as a teenager which
my mates loved to give me a hard time about. Had numerous crashes where
my head hit the concrete and I was ok. My friends all ended up getting
helmets after another friend crashed and split his head open and ended
up in hospital for 2 weeks because he wasn't wearing a helmet.

These experiences have showed me that across all types of riding when a
crash happens and a head hits the ground it is always better off in a
helmet. Admittedly I have put myself into situations where the
likelyhood of a crash is higher (that is why I wore a full face helmet
in DH) but two of my worst crashes that inflicted the most damage both
occured below 10kph in a road setting.

The incident that caused the fractured skull would have been quite
funny to my friends if I hadn't have been unconcious and vomiting (so I
am told) on the side of the road.


--
Paulie-AU

smartie wrote:
A bike helmet must meet the Australian Standards no matter how old it
is. This implies that the latest helmet shall meet the same minimum
standard as the Rosebank Stackhat of 20 years ago.

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

So for impact
protection they both provide similar protection. (remember here that
one is a soft shell and the other a hard shell). The main difference
with a modern helmet is that it is a lot lighter and has better
airflow. This also goes for the bottom to top of the range.

Looking at the foam padding of them, the polystyrene is pretty much the
same in both and that is what does all the work. The shell merely stops
the foam from being ground away as your head runs along the ground.

Provided the Polystyrene is in good condition (i have always checked
polystyrene by seeing if it is going chalky) there should be no reason
why i would stop using it apart from daggy looks.

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.
I would not want to keep using a helmet beyond these limits without
some method of accurately testing a helmet (other than destruction).

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

TimC wrote:
On 2006-01-04, Theo Bekkers (aka Bruce)
was almost, but not quite, entirely unlike tea:
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?

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.

Theo

Rayc wrote:

Not an arguement, just an observation.

if your happy to keep using something that is widely accepted as
outdated and sub standard, then by all means.

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

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.

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.

Random Data wrote:

So did you? I dropped bricks on the last few helmets I had to get rid
of - they were showing cracks and/or depressions after a few largish
hits, so I thought it was time to get rid of them. A house brick,
edge on, leaves a fair mark in a helmet from about 3m up.

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

Theo

Random Data wrote:

Moto helmets are very different from push bike helmets, and I suspect
exceed the design requirements by a fair bit. Out of interest, was
there a noticeable difference between new and old, or were the models
sufficiently different that this wouldn't mean anything?

Motorcycle helmets have to pass a penetration test by having an object (your
brick?) dropped on it at 23 km/h. Hmmm again.

Theo

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