So i remember reading about helmets expiring and how the liner and sometimes the shell can decompose over time, thus needing replacement. So i look at my helmet and its about 6 months shy of its five year expiry date? So whats the deal with this? Will my helmet spontaneously combust after this. How does a liner/shell decompose over time? Does it oxidize? Do i have to vacuum seal my helmet in the off season to prolong its life. My helmet is in mint condition and it seams like its barley been worn over the course of its life. Any comments. I'm sure theres been a post on this before i'm just a relative newbie. Thanks guys. Peace.