Page 28 - PBCSeptember2014

Pickwick Bicycle Club Magazine Volume 11 No.2 September 2014 !28

Paper Helmets & Woodpeckers make it safer for Cyclists….really?
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For one man, having a potentially serious bike accident got him thinking about a new
style helmet design. “I was riding downhill when this guy opened his car door,” says
Anirudha Surabhi. “I hit the door, did a couple of somersaults and fell straight on my
head. My helmet was cracked and completely unusable.” Luckily he walked away with
minimal damage apart from mild concussion. As a design student he investigated
alternative options to the standard polystyrene construction.
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The UK Transport Research Laboratory researchers say that ‘when falling off your
bike, your head suffers a dramatic speed change in a fraction of a second. When your
head hits the ground your skull stops, decelerating rapidly, but your brain being of soft
tissue tends to keep going. Try dropping a blancmange on a plate – the top compresses
downwards. The same happens with your brain.
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Cycle helmets are really only a mini-crumple zone – helping to absorb some of the
energy to give your skull/brain more time to slow down – and usually makes the
difference between brain damage and concussion, like Anirudha. Since they are only
made of polystyrene, Anirudha looked into the natural world for inspiration and found it
in the woodpecker! These birds peck at ten times per second and sustain a similar amount
of force of us crashing at 50mph. However this is the only bird where the skull and beak
are disjointed, with soft cartilage in the middle to absorb the impact. (And stops it
getting a headache!)
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So Anirudha, used paper to make a double layer honeycomb that could then be
constructed into a helmet. ”You end up with multiple tiny airbags throughout,” he says.
“Then when you crash, these pockets go pop, pop, pop, all the way through, without the
helmet cracking, and this is what absorbs the energy.”
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The design has now been tested to EU Standards (Oh dear -editor) with impressive
results. A 15mph crash with a standard helmet subjects your head to >220G (G-force),
whereas Anirudha’s design absorbs much more impact reducing this to >70G. ISO safety
standards recognise that to avoid serious brain damage a person should not be exposed
to an impact above >300G. Therefore whilst your standard helmet offers good
protection, the paper helmet gives your head more time to slow down.
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Pretty impressive eh? No, multiple paper bags will not provide the same effect.
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