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Originally Posted by IshaanIan I was actually going to quote you earlier for the fact that the article discusses the obsolete 2005 SNELL standard, actually the fact is there are several such articles that I came across when I was trying to research the most technically sound helmets, that point out flaws in nearly every standard out there including the SHARP standard. |
True, that's where the science of crashing, and materials/energy , needs to be figure out and build upon, or if they already have that knowledge, now come out and tell the riding public in plain English what they know. SHARP seems to have taken this route (of conveying to the public) better, though the black art/science of energy absorption/dissipation is not clear.
For example, you know what material lot of premium helmet brands use for the shell ?
They're usually composites - frequently called tri-composites because they layer glass-fiber, aramid (kevlar) and certain other thermosets, with differing ratios and processing parameter, so that they can all claim proprietary rights, but none of them have been tested and measured.
HJC call theirs PIM (Premium Integrated Matrix), Shoei call theirs AIM+ , Arai call theirs PB-SNC (Peripheral Belting-Structural Net Composite). Now, fiberglass itself is of several types (the fibers, E and S type being the common ones and S being the superior one). We don't know which brand uses which - now mix other types of polymers into the fray (aramids and other layers) and it's all getting complicated because there are mutiple types of raw materials and processing methods.
For the super-premium models/variants, they get a layer of carbon-fiber (no, I doubt there is any brand that has a full carbon-fiber only shell - it probably will be too expensive, being the main constraint that being too stiff seeing that helmet shells aren't very thick.)
Except that mixing, rather layering different types of fiber-resin composites doesn't really give the maximum benefits of each type. As per this video, an outer layer of carbon fiber is least useful/beneficial since the tensile strengths vary.
Yet, all the helmet manufacturers use a mix of different layers (I doubt there is any helmet shell that's purely fiber-glass only, either) and then at the premium end, offer carbon fiber helmets that by the explanation in the video above, is quite possibly pointless. This video is not in the context of helmets but generic - say more for composite panels for a race car and you need to decide to use fiber-glass or carbon-fibre or layers of both.
Do the helmet manufacturers know something this guy doesn't ? Or is it that helmets are supposed to be discarded after one/first impact itself, so helmet manufacturers don't bother with that aspect.
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Originally Posted by IshaanIan Doesn't have the ACU Gold sticker either which is to my knowledge the requirement for track use in the UK. |
As @ethanhunt123 noted, ACU have diluted their credibility by going commercial and selling their stickers without verification.
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Originally Posted by IshaanIan  right fit comes first, then comfort of the inner lining/ventilation/visor mechanisms etc. As far as safety goes, I am fairly confident in most of these brands anyway. |
Yes, that's the point. Despite advances in materials and understanding of crashes, forces and the effects of those, there are still grey areas and outside of laboratories, real world accidents can be very very diverse, and lab tests cannot reliably replicate all aspects.
What SHARP ratings do show though - if a helmet was hit with a hard, in-compressible object of certain weight and size, with a certain amount of kinetic energy or force, at some specific positions (forehead, sides and back of the head), at specific angles, the amount of energy transmitted to different helmets varies, and the best regarded brands and models don't always come out on top or get all highest scores.
In the real world, you rarely will hit a similar object in exactly similar way- like say a lightpole, exactly at the forehead or side directly vertically ; but if you do, reality may concur with SHARP's test that the 3 star Arai or AGV wasn't any better (or probably worse) than a cheaper but 5 star Kabuto or HJC. As to how the forces get distributed and absorbed at other angles, that's still unclear to most of us, and claiming an Arai or Shoei is safest is more brand faith than proven fact.
This might not cause any fans of X or Y or Z brand to budge, but for the buyer on a budget, they should be clear that buying a $100 plastic helmet isn't anywhere as risky or foolish as helmet brand snobs who'll only wear an "Arai or nothing" (my twisting of the Jockey or nothing ad

) make it out to be, and a $500 helmet isn't 5 times safer. At the same time, you have only 1 head so buying the safest helmet you can afford is the goal, since a difference of 20Gs in a crash could be the difference from a mere concussion to internal hemorrhage perhaps, but buying the safest helmet isn't anywhere as clear-cut even with all the ratings and methods.