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Time to retire this helmet?
- Thread starter jarobo
- Start date
Alex Dlugosch
Likes Dirt
We should also remember that not only does the EPS absorb energy by compressing in bulk, but also by cracking. Cracks might not be evident upon inspection because the place where the crack is may not have separated enough to allow you to see it.
A cracked helmet experiencing another impact may have vastly decreased ability to absorb energy, even if the EPS foam is not already compressed much. The crack may prevent force from being transferred through the material, allowing the helmet to deform into your head more and transfer more energy to your head, which is not what you want.
I've always liked the saying "A 20 dollar helmet for a 20 dollar head"
A cracked helmet experiencing another impact may have vastly decreased ability to absorb energy, even if the EPS foam is not already compressed much. The crack may prevent force from being transferred through the material, allowing the helmet to deform into your head more and transfer more energy to your head, which is not what you want.
I've always liked the saying "A 20 dollar helmet for a 20 dollar head"
sammie_wood
Likes Bikes
i crashed multiple times lightly with my previous helmet, got a couple dings here and there, didnt think much of it... Was riding the skate park for a change and clipped my peddle and got sent, knocked myself out on a rather light crash, the helmet was f****d to say the least, didnt offer any protection at all, now im the same, one crash and i replace it.
Ultimately it depends on how much you consider the manufactures instructions to by covering their ass against any liability. Personally if it isn't cracked on the inside I'd keep it. But I don't expect my helmet to save my life in major crash. My expectation is that it will prevent minor impacts from being major injuries.
^ Some what agree with this... Helmets crack as part of the energy dissipation process...however without seeing the actual scientific data I would expect that a crack you that is not visible to the naked eye is still dense enough for the impact energy to propagate across, just not as efficiently as if there was no crack. It's just that a crack has a greater potential to split apart rather than dissipate the energy.
It many also depend on the crack direction and the location of impact, heads are generally roundish and don't point load, so could quite easily impact the foam on both sides of the crack simultaneously.
We should also remember that not only does the EPS absorb energy by compressing in bulk, but also by cracking. Cracks might not be evident upon inspection because the place where the crack is may not have separated enough to allow you to see it.
A cracked helmet experiencing another impact may have vastly decreased ability to absorb energy, even if the EPS foam is not already compressed much. The crack may prevent force from being transferred through the material, allowing the helmet to deform into your head more and transfer more energy to your head, which is not what you want.
I've always liked the saying "A 20 dollar helmet for a 20 dollar head"
^ Some what agree with this... Helmets crack as part of the energy dissipation process...however without seeing the actual scientific data I would expect that a crack you that is not visible to the naked eye is still dense enough for the impact energy to propagate across, just not as efficiently as if there was no crack. It's just that a crack has a greater potential to split apart rather than dissipate the energy.
It many also depend on the crack direction and the location of impact, heads are generally roundish and don't point load, so could quite easily impact the foam on both sides of the crack simultaneously.