Nick,
Some of it comes down to ...well no it
all comes down to dollars (Euros, Pounds,Lira, Marks, Francs) whatever...either due to the need to sell more inventory...or due to the liability...if you tweek your bean with a 10 year old helmet and your families crack lawyer can get three experts to say it deterirated and the MFG never TOLD you that might happen...then while you do your best impersonation of a cabage...your family is collecting millions and the company is wondering why it didn't tell people they need to replace every 2, 3, however many years...
even Snell will tell you that SOME materials used by SOME manufacturers MAY degrade...so they use a blanket 5 year recomendation...(with the usual disclaimer...check with the mfg...)
Personally I find that the NON safety related foam (like the cushy pads on the chin strap and cheek pads)...starts to crumble and leave foam dust all over the place long before the safety stuff will ever give in...so off I go fo a new-less-dusty bean bucket...
ANY bucket is better than NO bucket....but THAT is an entirely DIFFERENT debate
