Best Motorcycle Helmet: Part 4
This article is part four of a nine part series on determining the "best motorcycle helmet". Part 1 listed six criterion one might use for picking the "best": G-loading limits, protective proposition, customer satisfaction, comfort and fit, intended riding use, styling. Parts 1 and 2 treated customer satisfaction, styling, and protective proposition. Part 3 started to explore G-loading limits with a definition of G-loading, research findings on the upper limits on how much G-loading a human brain can withstand, and the G-loading failure criteria of various motorcycle helmet safety rating standards. We left off by asking if a certified Snell motorcycle helmet is the "best motorcycle helmet."
The short answer to that question is: NO. To understand why, you first need to understand two things: the make up of the modern day motorcycle helmet and the circumstances of most motorcycle accidents. First, a modern day motorcycle helmet has two major components: a hard penetration resistant, shock absorbent outer shell and a soft non-resilient energy-absorbing expanded polystyrene (EPS) foam inner shell. The outer shell is intended to distribute the impact load over a large area and are made either from fiber-reinforced plastic, such as fiberglass dyneema, aramid, carbon fiber, Kevlar, or a composite of these, or from thermoplastic, such as Acrylonitrile Butadiene Styrene (ABS) and most recently polycarbonate/ABS alloys. EPS foam inner shells are intended to absorb energy by crushing, which is why you should never wear a helmet that has been worn in an accident situation. Plus, a used motorcycle helmet that has been worn in an accident may have a compromised outer shell with fractures that are invisible to the naked eye. Check out my article on used motorcycle helmet advice for more on this subject.
Regarding the circumstances of most motorcycle accidents, the 1981 Hurt Report - the first, last, and only serious study on real motorcycle accidents...