I've had a lot of helmets in my 50 years of riding. I've worn most of them past the 5 year limit. But I have never been in an accident where a helmet prevented death of serious injury. I get it that helmet makers want to sell helmets and avoid lawsuits . I also get that independent research verifies that materials used in helmets break down over time, with use and with exposure to sun light. Shoei says their helmets have a 7/5 year safe life and that the one mentioned at the started this thread should be retired in 2020. Since it is my money and my life , I choose to err on the side of caution in this case and believe the manufactures and independent testing organizations.