Chockstone Forum

      Sponsored By
      ROCK
   HARDWARE

Chockstone Photography

Australian Landscape Prints

Chockstone Forum - Gear Lust / Lost & Found

Rave About Your Rack Please do not post retail SPAM.

Author

Sun damage to helmet

cruze

14-Oct-2010
3:08:18 PM

At the risk of combining two topics that bore most people to death, does anyone have a feel for how often helmets should be replaced? They cop a lot of sun and could foreseeably become quite brittle and weak over time. BD Half Dome if it matters.

Has anyone ever had an old helmet shatter badly?

I realise that this post will cost me the miniscule amount of credibility I may hope to have gained on Chocky over the years, but I was forced to post here on behalf of someone who shall remain nameless. For now.

widewetandslippery

14-Oct-2010
3:19:59 PM

I've always thought the busting the empty longneck over the 20 year old helmet trick to put the smasher in greater danger than the smashee.

DaCrux

14-Oct-2010
3:36:16 PM

apparently the maximum shelf life of a BD half dome is 10 years

Lifespan
The lifespan of your helmet is dependent upon how frequently you use it
and on the conditions of its use. With occasional use and proper care the
lifespan of a textile or plastic product is 5- 8 years, with frequent use and
proper care the lifespan of a textile or plastic product is 2-5 years, and the
maximum shelf life is 10 years.

Factors that reduce the lifespan:
◆ Impact—both severe and mild
◆ Abrasion, cuts, wear
◆ Heat
◆ Sunlight
◆ Corrosives
http://www.blackdiamondequipment.com/uploads/black-diamond/files/MM5887_B%20Helmets%20IT%20WEB.pdf

The good Dr

14-Oct-2010
3:46:25 PM

Why not just go to the Black Diamond website and find and read the instructions. You can ignore them if you want. It is that simple really.

cruze

14-Oct-2010
4:07:24 PM

Yeah I missed the bit in the instructions about personal experience with helmets shattering. Whoops! Thank goodness there was someone lurking on the internet that had sufficient time to point out how simple the bleeding obvious is.

Dane

15-Oct-2010
1:42:24 AM

Then I think you may need to imagine harder.
The UV light breaks the interatomic bonds in the polymer, making it more brittle, and weaker...
How long this takes is dependent on the polymer and the amount of exposure.
but certainly I'd be expecting them to last ~10 years for a hard shell. A foam one on the other hand would be a lot shorter.

ajfclark

15-Oct-2010
7:55:58 AM

I have two half dome helmets, one that gets used a lot and one that doesn't. They're distinctly different colours because of the different levels of exposure they've had to the sun. Sun slowly makes plastic brittle... Look at what happens to UV Stabilised patio furniture. It still eventually cracks, splits and drops someone's drunk arse on the ground. I don't see why a helmet would be any different except it'd take heaps longer because it's in the sun less time.

cruze

15-Oct-2010
10:30:15 AM

On 15/10/2010 Dane wrote:
>Then I think you may need to imagine harder.
>The UV light breaks the interatomic bonds in the polymer, making it more
>brittle, and weaker...
>How long this takes is dependent on the polymer and the amount of exposure.
>but certainly I'd be expecting them to last ~10 years for a hard shell.
>A foam one on the other hand would be a lot shorter.
>
That is certainly what I thought for hard shell helmets and I would be surprised if the impact resistance of the shell would degenerate in 10 years of average use. On the other hand I would probably disagree with your foam estimate of being shorter - they tend to have a very thin outer layer which would probably reduce UV exposure to the foam by quite a bit whilst at the same time not having to perform any strengthening.

jkane

15-Oct-2010
1:20:56 PM

On 15/10/2010 cruze wrote:
> On the other hand I would probably disagree with
>your foam estimate of being shorter - they tend to have a very thin outer
>layer which would probably reduce UV exposure to the foam by quite a bit
>whilst at the same time not having to perform any strengthening.

Hmm, then maybe you can make your helmet last longer by covering it with baking foil. And it would look SO cool - especially if you added a couple of antennae.

ajfclark

15-Oct-2010
2:52:02 PM

And it stops them listening to you.

patto

15-Oct-2010
5:15:07 PM

On 14/10/2010 davidn wrote:
>5-8 or 10 sounds like shenanigans. The webbing for the helmet straps,
>fine, but sun degrades hard plastic??
>
>Does this mean I need to replace my bins in a couple of years? Sure it's
>not going to sustain an impact, but I'm having trouble imagining microscopic
>sun razors making it weaker.

Um. Yes. !?!?!

Lots of plastic is degraded significantly by sun. Haven't you seen old plastic become brittle and crack due the the sun. Hose fittings, pool fittings, countless plastic items become brittle due to the sun. I would have thought that this was common knowledge.

**Of course there are many sorts of plastics and these degrade at different rates. Hard plastics seem more affected to my knowledge.

There are 11 messages in this topic.