Do helmets ACTUALLY degrade over time

[Mike Muz]

At the risk of opening a can of worms, does this actually happen? Or is it a ruse to get us to buy more?

Your thoughts please

Mike

 

[firedfromthecircus]

Discarded polystyrene does not biodegrade for hundreds of years and is resistant to photolysis.

The polystyrene doesn't degrade, and the plastic shells don't degrade. The glue holding them together may degrade over time, though my 1997 Specialized helmet is still in one piece. So mostly it's just a ruse to sell more units IMHO. There is the argument that over time the numerous small knocks that a helmet might get could affect its integrity, but then there is the massive elephant in the room of how effective helmets are in the first place. :roll:

 

[ishaw]

There was a thread on here with all sorts of science backing it up. I think the answer was no.

 

[itscervo]

Yes!, but the time it takes is dependent on the type of plastic. Say if they were made of Pla plastics, which I doubt, but having said that you never what comes out China, it can degrade in 90 days :shock: . Now if its Pet plastics they photodegrade unless kept out of direct light, but it takes a bit longer than 90days , so if you really want to wear that retro helmet, put a rain cover over it & always give your helmet a wipe every now & then to keep it nice & fresh .

 

[wesmamyke]

Purely personal experience for me says yes. The shop I worked in destroyed old helmets when people replaced them with new ones. We would hit them with a huge hammer at least a couple times to render them useless. Newish helmets are actually pretty difficult to destroy, takes quite a few blows to finish the job.

Really old helmets maybe five to ten years old not so much. They are much more brittle and almost explode into pieces when hit, or just split in two right away.

 

[Silvergoat]

Re:

Over prolonged long term exposure to sunlight, UV degradation may eventually make the plastic shell brittle, if there aren't sufficient UV inhibitors in the composition.

 

[player]

Re:

The shelf life in a cycle helmet is no different to the shelf life of a motorcycle helmet.The reason being the EPS (expanded polystyrene) used in both motorcycle and bicycle helmets absorbs sweat and grease from your pores into the polystyrene to a point where the EPS firms off and won't dissipate the energy as well as a new/fresher EPS liner.

Basically a well used ten year old helmet would work to a point but not to the extent of a newer one.

 

[The History Man]

Well if this is anything to go by:

 

[itscervo]

Re: Re:

Over prolonged long term exposure to sunlight, UV degradation may eventually make the plastic shell brittle, if there aren't sufficient UV inhibitors in the composition.

That is very true, different areas have different requirements.
http://info.craftechind.com/blog/bid/38 ... bilization

 

[Mike Muz]

Re: Re:

The shelf life in a cycle helmet is no different to the shelf life of a motorcycle helmet.The reason being the EPS (expanded polystyrene) used in both motorcycle and bicycle helmets absorbs sweat and grease from your pores into the polystyrene to a point where the EPS firms off and won't dissipate the energy as well as a new/fresher EPS liner.

Basically a well used ten year old helmet would work to a point but not to the extent of a newer one.

I can't imagine that the EPS would get much sweat, given that I use caps under the helmet norally, plus the padding within the helmet? Maybe it only needs a little.

Someone previously mentioned them breaking easily once they have had an impact. In the case given, a hammer.
Isn't that what they're meant to do? Absorb the impact and break.

Mike