Both have an M2010 Snell sticker.
To ease any concerns about environmental degradation, both helmets have been protected in boxes since production except for the 2x 2 hour rides on the size Large and 1 hour on the XS.
Thanks for the info, I just wanted the expiration dates to be known.
Foam degrades over time, that's just a fact. Helmet age recommendations are there for a reason: Your head.
According to the experts I spoke with at the SNELL foundation in Sacramento, CA, foam degradation varies depending on the storage environment and air quality.
I spent TWO DAYS with the SNELL principles some years back interviewing them for City Bike magazine. I learned a lot from these true helmet experts. They test and destroy helmets for a living and established the SNELL standard about 30 years ago.
But they also know A LOT about helmet manufacturing, helmet materials and construction. They not only smash them and measure the force, they cut them up and analyze material quality and construction. Not super high tech like Rocketdyne or General Dynamics but pretty accurate results. Both Shoei and Arai do massive testing ... but won't even talk about the testing or results.
They also visit helmet factories in person every other year and have been to them all, including the major factories in China ... who's output accounts for DOZENS of brands, most of whom you never heard of and most are NOT submitted for SNELL certification as it adds to bottom line price. OEM's PAY for SNELL certification.
They felt Shoei and Arai were still the GOLD standard of helmets. Both are super secretive and don't share what they know and would not talk details with the SNELL guys but do give them guided factory tours.
The SNELL guys were very impressed with HJC who were far more OPEN and felt they were getting close to the Japanese. The Chinese by now can make as nice of a helmet as anyone is willing to pay for. Problem is, most wholesalers go CHEAP and most riders go Cheap too ... and so this is what we get. CHEAP.
Regards how long helmets last, they did admit the typical 5 year limit is partly
hyperbole from OEM's, as a properly stored helmet should last much longer than 5 years.
Bottom line, if kept INSIDE in stable temp environment ... the polystyrene foam should last easily 10 years or longer.
The worst place you can store your helmet (most riders do this!) is in your garage or in a place where hydrocarbon fumes are present. Even parked cars or or motorcycles give off toxic fumes. We all hear our Ducks Singing when parked!
These fumes Very bad for the critical foam that protects your noggin in a hard hit.
Next bad storage place is in HEAT. Obviously, direct exposure to Sun is not good either and attacks both outer and inner materials. If your helmet is used outdoors everyday .... I WOULD follow the 5 year limit.
So, bottom line is, if those two helmets have been stored inside, in a controlled environment, then I'd bet they are safe. If in doubt, take them up to SNELL and they will test them for you! Unfortunately your helmet won't survive the test.
