can you find a real serious warning frm any reputable helmet maker that says that helmet should be changed after 5years.
i mean a real serious warning/disclaimer.
what if rider only wear 2 times a month, compare to rider wears everyday.
their helmet starts deteriorating once placed on the head?
or out frm factory?
what about helmet tht was on display for over a year... ??
all these have not been really studied...?
Seems you've not tried looking.
I think some of these sounds serious enough to absolve the manufacturers of any claims.
Shoei: Helmet Replacement
Ultimately, the useful service life of a safety helmet is dependent on the intensity and frequency of its use. Helmet replacement is recommended even if only one of the under-mentioned points applies:
1. The helmet was subjected to an impact.
2. The comfort padding or the retention system has become loose due to heavy use or display signs of deterioration. Test: with the retention system fastened, the helmet turns to the side when you gently shake your head.
3. The EPS liner has come away from the helmet shell.
4. The EPS liner shows signs of wear and is beginning to break up, or if it has been exposed to heat or a solvent and has melted. There are indentations in the EPS liner and/or white scratches can be seen on surfaces with black paint.
5. Even if none of these is applied, we, SHOEI, recommend replacement in 5 years after it's first purchased at retail.
source:
https://www.shoei-helmets.com/helmet-maintenance/Arai: How do I know when my helmet is past its best?
Arai helmets are handmade to the highest possible standard, and although after many years the outside shell can look as good as new, it’s the EPS polystyrene liner that loses its ability to absorb impact over time.
Arai recommend replacing your helmet 7 years after date of manufacture and 5 years after date of purchase to maintain the maximum levels of protection.
The EPS liner is effectively the shock absorber of your helmet, absorbing the force of an impact onto the shell. This is done by the cells in the poly styrene being expanded (EPS = Expanded Polystyrene) and filled with air to absorb impacts.
Over time, even when not in use, these liners lose their air pockets incrementally, after 7 years, dropping the shock absorbing ability of the liner below Arai’s safety standards. This is why we declare the helmet due for replacement so it can properly protect you against impacts.source:
https://support.whyarai.com/support/solutio...-past-its-best-Caberg:
Is the production date visible on the helmet?
Researches have shown no evidence of degradation of the materials (used in the helmets manufacture) due to the mere effect of the times passing by. Nevertheless the exposure to the atmosphere agents (extreme hot and extreme cold), and the contacts with the vapors of the lubricants and gasoline normally used in the motor bikers environment may influence the molecular links of the materials used. Moreover, because of its own nature, the helmet often undergo to shocks of different amplitude that could limit its performances. For all these reasons and for the abuse to the comfort padding and for the technical evolution that make more modern and protective lids available, it is suggested to replace the helmet after 5 years of use. In case of intensive use this delay should be shortened accordingly. If a helmet supports a severe blow, even if there is no evidence of damage, it should be replaced.
source:
https://www.caberg.it/en/faq/