here's what I found....
Why should you replace your helmet every five years?
The five-year replacement recommendation is based on a consensus by both helmet manufacturers and the Snell Foundation. Glues, resins and other materials used in helmet production can affect liner materials. Hair oils, body fluids and cosmetics, as well as normal "wear and tear" all contribute to helmet degradation. Petroleum based products present in cleaners, paints, fuels and other commonly encountered materials may also degrade materials used in many helmets possibly degrading performance. Additionally, experience indicates there will be a noticeable improvement in the protective characteristic of helmets over a five-year period due to advances in materials, designs, production methods and the standards. Thus, the recommendation for five-year helmet replacement is a judgment call stemming from a prudent safety philosophy.
this info is off of Snell foundation web site. so what it's worth, there you have it.
myself, I can not afford to go out every 5 years and throw down $300 on a new helmet. so my "old", 5 year + old helmet is just going to have to do. the way I see it is, even an "old" helmet is better than no helmet.
if it goes vroom or boom, I LIKE IT!
Last edited by ruger; 07-12-2015 at 07:26 PM.