grmnxtc

Ok, I stand corrected.

However, I would still maintain the logical conclusion that using a full face helmet would increase the risk of a broken neck.

Considerthis:

1) A full face helment puts an extra mass (chin area) closer to the deploying airbag.
2) Airbags deploy at a lower level than the chin, and therfore cause a reactionary upwards thrust to the helmet upon deployment and contact.
3) Whilst helmets protect against head injuries, they are not good at protection from an upwards and rearwards "thrust", causing the head to bend back.

The design of helmets causes a fulcrum movement (back and up) and the rear of the helment causes extra stress to the vertebrae (IIRC between the third and fourth) and in these circumstances can often result in a broken neck.

Like I said, a logical conclusion (mine!) why not to use a full face helmet with an airbag. My reference was, as you point out, an incorrect one, but my thinking is clear enough (to me at least!).

Anyway, I'm sure the debate/discussion will rage on, but my choice would be to minimize the risk, along with affording reasonable protection to the head as a result of a crash (and I'd hope that doesn't happen to me ever!).

All Racing activity is by it's nature hazardous, and risk and benefits need to be balanced. Everyone's choice is their own, YMMMV etc etc ...yada yada yada...

STLPCA

The major differences between Snell M & SA helmet standards are:
1. M helmets must meet a single impact test (your head hits the ground). SA must meet a multiple impact test (car rolls over & over - your head hits the roll cage over & over).
2. SA must have fire resistent linings. M aren't required to since getting engulfed in flames on a bike must be pretty rare.

FWIW, my PCA Region permits open/closed M or SA helmets for DEs.

tabasco

Texas 911,

I'm also in Houston and go to most DEs at TWS.
Open face helmets are allowed, and I have one. I took an open face helmet because :
- Better angle of vision. Full face are usually narrower.
- Less sound isolation. I hear the engine, tire, and other noises a lot more, and that's good while on the track.
- I read that full faces are not recommended if you have an airbag.
- Better for our climate in Texas. You breathe better.
- Lighter.

If you're getting prepared for you first DE, welcome on the track, you'll love it.
Too bad I can't make it for the april DE, it's the same day as the Houston-Austin MS150, so I'll be riding my bike for the whole weekend instead of the 993

I bought my helmet in a mototorbike shop on I10. It was pretty cheap, it's confortable, I like it. Dunno the brand.

Hope to see you someday on the track !

-Guillaume

Randy M

So then are SA helmets better helmets all around? Why wouldn't Arai, Shoei and the others produce a motorcycle helmet as per the SA standards? Motorcyclists would demand the safest most protective helmet available wouldn't they? I have what I think is the safest best fitting helmet available w/ my Arai Signet GTR but if an SA helmet is an inherently safer helmet then I'm a little ticked...

Tom W

Why would a motorcycle driver want to pay the extra money to have a Nomex layer in his helemt to make it fireproof? I don't think an SA helmet would be any more "safe" than an M helmet when riding a motorcycle, it would just cost more. A motorcycle driver always has the option to buy an SA helmet if they want one. You may have the option to buy an M helmet for autox (if your group is like ours and allows it). However, you may then have to buy a new helmet for DE if the group requires SA helmets (ours requires SA for time trials).

Randy M

A nomex layer is not the issue. I'd be interested in exactly how the testing differs between an M helmet and an SA helmet. An SA helmet may be uncomfortable on the neck while riding a bike as I believe there is more of a cutout in the back of an M helmet to facilitate a rider bending his neck more than someone in a car.

Bull

I believe that else where on Rennlist people have posted the exact test proceedure wording. To my knowledge, the two main differences are the nomex liner in the SA and the testing for hard hits at or near the top of the helmet to simulate rollbar impacts, rollovers, etc.

The cutout on the rear edge of my M helmet and SA helmet are about exactly alike (sitting in front of me now). The SA helmet has more impact absorbing material in the top of the helmet. I sits rises higher above my head and impacts headroom slightly.

STLPCA

Randy - I suggest you go to Snell's website & read the test procedures & standards for the answers to your question.

Dave R.

GRMNXTC wrote
Why not wear one of those special protective foam "anti-whiplash" collars together with a full face helmet (and disable the airbag)?

grmnxtc

Dave R.

Good point, but the risk of broken necks is increased with the use of a helmet regardless of it's type. Both have about the same design at the rear, and both add mass to the head which causes extra strain on the neck muscles when your head an body want to move in different directions.

Remember that most "race" cars do have the airbags disabled/deleted ... but the question was the use of a helmet for DE events, impying everday use thereafter and the (supposed) wish to retain the airbag for everyday "safety" (my assumption)

You can disable the airbags on the 993 in two ways:

1) Use a Bosch Hammer and PERMANENTLY disable either side (no going back).
2) Install airbag deactivation switches (needs NTSC approval?), and maybe forgot to disable/enable it at the appropriate time?

OK, there's also a third way. Take out the airbag and put up with the light on... but this then offers no protection on the daily use.

A catch 22... and as I said before.. the choice is yours...

My money goes on an open face (as you HAVE to have a helmet) and the car remains "stock" as far as the built in safety devices goes...Then there's the whole other argument about how "safe" 1st gen airbags are anyway....

Bottom line, you just can't win!

Clive.