To understand how helmets function, a little bit of physics is helpful. For the laboratory tests, a test speed of only 28 kilometres per hour is used. This is about the speed of a fast bicyclist. Not a very realistic speed for motorcycle use. And under real world circumstances, there is not limit whatsoever to the severity of a single impact or even multiple impacts. Real world circumstances are simply much more demanding than any test lab standards can simulate.



OK, what would happen if we increase the test speed then to say, 100 km/h? The results are spectacular: when the speed is increased by a factor 4, the impact energy will increase with a factor 42 = 16! No helmet is able to sustain such an direct impact or guarantee absolute protection. Not even an Arai helmet.


The wearer of the helmet may be moving much faster than the drop speed of the impact tests. Still in the real world, riders walk away from crashes at even much higher speeds. How is that possible? By minimizing the impact energy that is directed into the helmet. This is realized by letting the helmet to slide over and to glance off objects.


It’s important to know that the impact energies the helmet needs to absorb may be dramatically reduced if it can glance off obstacles and slide across uneven surfaces, diverting impact energies.


a little bit of physics

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