John Veninger

Thanks Gregg!!
I know there are some "issues" on how the SFI certification is written, but having your device meet the same specification as the HANS puts to rest the mine is better than yours stuff.

A quick disconnnect?

gbaker

Having spent 20+ years dealing with structural implants (arthroplasty and fixation) I can say the SFI process is very different from that of the FDA. With respect to medical devices, if you develop something new you design a study to demonstrate safety and efficacy. If you believe it is safe and efficacious you take your study results and submit them to the FDA. If the FDA agrees it will approve it.

For this product category the SFI Spec calls for head loads not to exceed a certain value on a specific 68G sled. These numbers are not challenging for us. The problem is that if we get these same values on a 100G sled we can't get certified because it is a different sled. The worse part of the Spec is that a manufacturer is not required to submit all test data. You can have 99 failures, one success and submit the successful results only with the world being none the wiser. This has already happened.

This protocol would be laughed out of any medical or military organization.

In order for SFI to "certify" a product you must join SFI, sign an agreement with SFI, pay SFI a fee every time you use its logo on your product, retest every model of your product annually (even if there have been no changes), and reimburse SFI without limit if SFI chooses to retest your product. It will cost about $10,000 to test each model. We spend a lot on R&D, so the dollar amount would not be an issue if we were developing something new. But in this instance it is down the drain and gets passed on to the racer. As soon as the R3 was "certified" by SFI the price jumped $200.

gbaker

You're welcome, John.

No, not a quick disconnect. SFI wants an "open" connector, which, BTW, we believe is dangerous. But that's another story.

garrett376

Gregg, thanks for answering all of these questions! Your honesty and helpfulness is why my Isaac is arriving on Monday!!

gbaker

Hey Garrett, thanks for the order! And the compliments.

The little bird at FedEx.com tells us it is enroute to the Memphi sort facility at this moment. Monday delivery should be a piece 'o cake.

SundayDriver

Thanks. That makes sense.

RedlineMan

Gregg -

If you'd be so kind to offer your experience.

It is my understanding (which I have stated here) of bio-mechanics that the head will naturally rotate forward, chin downward toward chest, in a frontal impact. This is regarded as a good thing in that this presses the strongest part of the skull into the front of the helmet bucket when an H&N device takes up. OK so far?

The only way I can see any H&N device having an effect on helmet position relative to the head is in this circumstance where, without a H&N device, the helmet is apt to fly off the head, save for the properly adjusted chin strap. Even then it will project itself quite well off the head without the retention of an H&N device holding things in line. Yes?

Your repsonse to this is welcomed, and your annoyance understandable (and appreciated), if indeed there is BS in the air here. However, I am not quite clear on what HANS may be claiming, and what your response entails in terms of these alleged claims, which I might add I have seen or heard. In other words, please explain this situation, and the reason for your annoyance with it, if you would. Methinks there is good crash information to be had in such a description.

If I may, I cannot see how ANY H&N device would have any effect in anything other than a forward projecting manner, be it strictly longitudinal, or with a lateral component. Might they be claiming that their device keeps the helmet situated properly on the head at all times and in all directions? Having nothing more than intuition to go on, this still seems patently rediculous to me.

gbaker

Agreed.

Exactly. This is a rare instance where head loads can be inferred from images. An unprotected driver experiences the helmet attempting to pull the head off the neck; an Isaac-equipped driver experiences the helmet holding the head on the neck. Notice that there is no requirement to hold the head up, only on.

Hubbard/Downing is claiming that only their product keeps the helmet from rotating backwards as the body rebounds back into the seat. My annoyance has two sources: 1) Who cares, assuming it’s true, and 2) it’s not true. In the Who Cares department, if my head is going backwards that’s exactly where I want my helmet to be. True, chinstrap loads can cause throat injuries in cases of extreme displacement, but that’s a small price to pay given all the hardware behind the driver’s head. In the It’s Not True department, see Wayne State sled test #17 (IIRC). Looks to me like there’s some nasty helmet motion with that HANS in place.

At a scientific level I find all this sales nonsense disturbing. The oldest trick in the book is to find some difference between your product and you competitor’s product and claim that that difference is in your favor—especially if there is no data for or against. I also don’t like picking and choosing data to present. Showing only favorable videos while refusing to release videos of the belts slipping off the HANS is a great example. Want to see another one? Go here: http://hansdevice.com/testResults.html. The bottom image is of an unprotected driver at extreme motion forward. You can tell because the arms are horizontal. Now look at the image above with the HANS. Assuming the concept of holding the head up has any value (which it doesn’t), the HANS looks pretty good, right? But why are the dummy's arms not horizontal? I don’t know for a fact, but I’ll bet a large chunk of change that that image is not taken at the extreme range of motion, in which case we have a classic example of false advertising.

If Hubbard/Downing wants to compare test data and videos, great, bring it on. But bring it all on.

The good news for us is that Hubbard/Downing’s credibility is dropping like a rock as more racers wise up. It’s self-destructive behavior on their part, especially since they make a very good product.

I agree that the rebound talk is a red herring, or at best a secondary issue, but there is real value in examining lateral impacts.

RedlineMan

Gregg -

Thanks for your reply. Every scrap of info or well-vetted opinon only adds to everyone's dossier. Your comments were in line with what I assumed your position to be.

I quite agree that posting full length incident footage is critical. Simply picking a "favorable" shot out of the sequence is... less than forthright, shall we say. Ah, but so goes the cut-throat world of advertising comptetition and competitive marketing. The highly ethical will let their offering stand on its own merits, explaining them fully, and really can do little more than mount defense against pure falsehood. Facts are difficult enough to obtain. Unfortunately, perception can be just as crucial, and is a hard thing to manage sometimes. "As Ye Sew..." does not always conclude itself in reality as it does in verse.

It would seem to me that all of the H&N devices - to varying extent - are "one shot deals." They ALL ultimately rely on stretchable fabric for their protective qualities, and as such are only as capable of handling further loads as the fabric is of resisting elongation.

Speaking strictly of secondary loading;

- HANS is "semi-actively retained," and thus completely reliant on staying under the belts. since belts will stretch, I see them as essentially "one shot," and that one is not quite without variable.

- Your device being semi-attached may have an advantage here, in the extreme, but I see it as so variable as to be realisitically slight. Assuming belt stretch is low, the Isaac will still be in their pitching, if we could so assume.

- The harness type devices (Safety Solutions) may indeed have a real advantage here, so long as their material stretch is not significant.

Again, and if I may speak for everyone, we do most appreciate your participation here. You have increased everyone's knowledge, and certainly done nothing but solidify your sound reputation as far as I can see.

gbaker

And sometimes the best defense is a good offense.

Amen.

Correct, but there is more. Dr. Melvin observed some of our testing and I had the opportunity to query him on this, and other, issues. Here is how he described the sequence: The head pulls the webbing, the webbing slides on the suit, the suit slides on the skin and the skin slides on the skeleton. In total, that can be a significant amount of displacement.

Worn loosely the harness products will reduce head loads by 45% (which can save your life); worn tightly (actually preloaded) the reduction can be as high as 75%.

Thank you. It's a good group here and we are glad to help.

RedlineMan

Just an update here, for the Lists' information;

It has come to my attention that there is indeed some evidence to suggest that the HANS device DOES INDEED have some benefit in rear hit situations.

The source for this is Hubert Gramling - formerly of Daimler Chrysler (where he developed the F1 airbag), now of the FIA Safety Institute. It is my impression that he may have been quite involved in the testing and developement of the HANS device, perhaps in conjunction with his own research in developing the F1 airbag. He says that his testing reveals that the HANS DOES offer some benefit in rear hits.

Apparently the benefit comes from the head hitting the HANS collar, not whatever is behind it. The collar's presence between the helmet and whatever is behind (seat, of rear bulkhead in a open wheeler) transfers some load from the head into the shoulders.

This is not quite the situation that is disccussed here (free recoil of the head), but could point out where some missinformation or mistaken attributation came from. While it is my impression that this may be a limited or highly variable benefit, it does appear to be at least minimally effective. Anything that helps is a good thing!

Geo

Great post John. I hope to be able to contribute some evidence that the HANS also provides protection in a side collision today. Someone from the SE-R Cup crashed and hit sideways and he could feel the tethers on the HANS do their job. I'll try to cross-post it later.

John Brown

John, please point us toward the source of Gramling' finding/statement/report.

Thanks

RedlineMan

John;

SCCA National Meeting - Safety Symposium lecture by Hubert Gramling. His talk was woefully short, much to his quite-apparent distress, but he did make mention of this along with the rest of his voluminous list of studies. Unfortunately, all he really was able to give was the list, and the briefest of mentions of a few details contained therein.

Again, this has little to do with free head recoil in a front collision (which I beleive was the basis for the complaint I quoted) but it is an interesting aside, and may indeed point out where someone strayed off the reservation with performance claims.

ColorChange

John, I can agree with your very minor and potentially better aspect of the HANS for rear collisions (although I don't know of many serious injuries that the HANS would have avoided) but will you grant me the much more applicable and beneficial early deceleration for both front and probably side impacts the ISAAC offers?