Anatomy of a helmet

[Danny]

Taken from another forum:
Those of you who have read some of my posts may have inferred the fact that I am against the temporary storage of one's helmet on seat or mirror. This is a learned feeling I have acquired by playing several impromptu games of Helmet Basketball (TM) with myself. One time, my helmet fell from the mirror, and one time it fell from the seat. The seat incident was very impressive because I was in a parking garage at the time, and when the helmet fell, the impact sounded like a cannon going off. I decided to push my luck after the first drop, but the second drop was the end of the helmet, no doubt.

So my former helmet has been sitting in the garage, gathering frowns because space in my garage is at a premium. I tried throwing it away once, but ended up digging it out of the trash, thinking "guest helmet", or "offroad helmet", or even "donation helmet". But my conscience got the better of me and I decided to heave it again. Better that it be thrown away than risk someone else's safety with it.

Then I got inspired. I thought, "I better destroy this thing just in case some dude finds it and tries to use it." So I took out my hacksaw and miter saw and went to work. I present to you my first anatomical cross section: the Shoei TZ-1.

This helmet is the bottom of the barrel when it comes to the Shoei brand. I bought it because it was affordable, had a good brand name, and came in matte black. The helmet's construction is as follows:

- 1/8 in. composite outer shell. The composite looks like fiberglass, with probably some carbon fiber and/or kevlar thrown in there. This shell was challenging to saw through, so I know it has some decent abrasion resistance. Note: my "new" RF-1000's shell is much harder to the touch, and the finish is more slick, so I predict that in a crash-and-slide situation, my RF-1000 would fare much better, acting as a kind of frame slider for the melon; the TZ1 with its matte finish and softer shell would seem to have the propensity for generating more heat and succumbing to abrasion degradation much more quickly. Who knows; maybe the super slick graphics you pay for would make it slide that much better.

- 1 1/2 in. styrofoam inner shell. The inner shell is made of the same material you would find in the packing of a new electronic component, only a little more dense. In other words, it's glorified box packing. It is bonded to the outer shell in a few key places. This inner shell seems to have the potential for good impact resistance, but if the outer shell was worn away by abrasion, the inner wouldn't last too long. Once my saw bit through the outer shell, the inner went very quickly.

- Cloth padding. The inner padding is made of synthetic material that is apparently designed mostly for comfort and a little impact resisance. But the foam used with the cloth is open cell and really wouldn't protect much. It would help air flow inside though. The cloth is really where Shoei saved money - the more expensive helmets have much more engineering on the inside.

My overall impression was that this helmet was made well, but a harder, slicker shell and better (washable) inner lining would make matters better. I think the TZ1 would make a great second helmet for the occasional pillion if you're looking to be frugal. The construction was probably representative of how most lids are made. But because of the foam inner shell it kept reminding me of a way to pack your head up and mail it UPS. Not the best of images, but you decide for yourself.

Go to my "website" to see the pics. I had this all nicely arranged for you, but Angelflamer is no longer allowing links to pics. They can't get you with popups when you remote link to pics. My expert photography is in the left bottom column, entitled "helmet1" through "helmet6". Lighting courtesy of Wal-Mart halogen light, unfinished garage walls courtesy of lazy owner.

www.angelfire.com/oz/hov/index.html

1. A profile of the helmet

2. No going back now

3. Left half of the helmet. You can see the small outer composite shell, the thick inner styrofoam shell, and the cloth inner lining fairly clearly. Note how the outer shell thickness varies with the contour of the helmet.

4. Right half of the helmet. When I finally got it apart, my wife was holding this side and she pulled the chin bar lining section out - what you see is pure outer shell, and how the chin strap is mounted to the outer shell. The little bit of foam you see on the forward part of the chin bar area is leftover foam from where the outer shell was bonded to the chin bar. Remember how I said that the foam was only bonded to the outer in a few places? There's one of the places.

5. Left half of the helmet again.

6. Two brothers, never to be united again. You can see I wear a size L, much like the size of Starscream's crack during road rash modeling sessions.

By the way, I found no obvious evidence of foam compression in the impact spots from the drop. But according to manufacturers, you must buy buy buy when your lid hits the ground. Probably some micro-fracture-fear-spend-money holes in the fabric of space-time developed without your knowing it.

[Mattastic]

You may find that your helmet pictures are not there?

Just looked at them now, was drunk when I posted before! I've seen similar when I did my CBT.
____________________
Too skint to buy a bike

[AcIdBuRnZ]

Oh yes they are!!!

Just look for them, gee

Mark
____________________
Past: Honda NSR125R >> Kawasaki ER-5a2 >> Kawasaki ZZR-600e1 >> Suzuki GSXR-750Y >> Honda VTR 1000 Firestorm
"Chickity China the Chinese Chicken..."

[hush]

Made for an interesting 10 mins of viewing. Nice breakdown, cheers.

[sv_cath]

If it happens again (god forbid!) most hospitals like them to be donated to them so they can do head injury research / practise taking them off 'casualities'
But thanks for the info anyway! LOL