Cycle Helmet Impact Testing
Photos from the impact testing of my 3 year old cycle helmet on 20 June 2006
Pictures uploaded on 05/07/06
Click on a photo to view it full size
What happens when you have two engineers with too much time, no work to do, an old cycle helmet that needs destroying and some Saxon reenactment weaponary? My friend Paul and I found ourselves in this exact situation in the two weeks following the end of our finals, so here are the results of our very unscientific, but rather satisfying testing! The helmet used was a three year old Bell (alas, I forget which model), and the weapon a reenactment saexs (it's kinda like a sword, but a bit lighter).
Before
The Test
Here is the video of the actual testing process. It's XviD encoded, so you'll need the XviD codec package (or a compatible one), which is available from
http://www.xvid.org.
After
It must be said, the helmet was a darnsight more resilient than either of us expected. In fact, even after the test, it was found to bear my weight rather easily (though, I am an eight and a half stone weakling) and even coped with me stamping on it. It finally caved in after a good stomping by Paul.
DISCLAIMER: Before all you h*lm*t fanatics out there jump on this and try to use it as evidence for or against your cause, I will be the first to say that this shows absolutely nothing. Firstly, the impact is unrealistic (unless you happen to cycle through a load of reenactors who don't like you very much), secondly the support of the helmet is all wrong (by leaving it on the ground, the helmet is supported by the rim, rather than by the inside surface as it would sit on your head) and thirdly, we have no idea how much energy was absorbed by the blow and how much of the impact was transmitted (two things are important: (1) how much energy of the impact is absorbed by the helmet - which you can get some idea of by the visible damage incurred by the helmet itself - and (2) the peak force transmitted to the head. Neither of these are at all visible in this test). My initial plan was to buy two melons so that we could have a direct comparison of with and without a helmet (which would also have dealt with problems 2 and 3 to some extent), but I never got around to buying them. Nonetheless, I present our results here as a bit of fun!
