schvetkaaks

I like the design, actually, as it provides mobility and protection from all angles. I'd like to see more data and some independent testing with other devices such as Isaac and Hans (and R3) for comparison. Of course it is better than no restraint, any such item would be, but how it compares in the barrage of tests is what would interest me most. SFI approval helps, but we want more...what happened to the fellow (not Dirk) from Leatt who was here early on the thread?

Veloce Raptor

BUMP


...and still no answer....

smokey

The cause of basilar skull fracture is too much tensile force betweem the base of the skull and the neck due to the head moving forward and rotating while the neck is restrained. A stop under the chin will simply put a compressive upward force on the jaw, providing a fulcrum point for the base of the skull to rotate around, and thus INCREASING the tensile force between the base of the skull and the neck in a frontal impact. A HANS device counters the rotation of the head by applying a force REARWARD on the helmet, and thus reduces the tensile force between the neck and the base of the skull. But you already knew that......

schvetkaaks

What is the primary benefit on the Hans device for the quick release tethers? Are the standard tethers that much of an issue?

mitch236

Not for EMS because they carry knives/scizzors anyway

Janni

I believe that the quick release tethers are for ease of driver egress. The HANS can get caught on the roll cage, or in the belts, etc. if you are not used to exiting the vehicle with it on. I have made a rule that my driver exits the vehicle after EVERY session with his helmet AND HANS so that it's second nature to NOT get caught on anything. This conditions him to exit the car the same way - every time. Practicing emergency exits is key - and you should be able to get out of your car with your eyes closed in 15 seconds.

gbaker

So, does that mean the HANS QR tethers are not SFI compliant?

Just amusing myself. Please, carry on.

--------------------------------
Gregg (the Isaac guy) Baker

Rick964

The instruction manual makes it seem as though the five point belts are an integral part of the device. Look at images 7 and 8.

Veloce Raptor

Exactly.

I actually prefer my HANS without the QR tethers...and I practice exiting with helmet & HANS every time I get into a race car.

ltc

It would appear as though DirkWiggler has left the building......

brucegre

Yeah, this is my concern, so does anyone understand SFI 38.1 well enough to explain whether or not this is part of the test? I could argue the other way, that the stop under the chin limits the rotational velocity, hence the sudden stop of the rotation comes early enough that the neck extension is limited - but then, I have no facts at all to support that, I'm just hoping it is so so I can rid myself of the tethers.

gbaker

SFI 38.1 only measures upper neck tension/compression (F-sub-Z) and, in effect, front/rear bending (M-sub-y). No side loads, no shear loads and it doesn't give a hoot about combined loads at prominent bony structures, much less principle stresses which, when compared with bone strength, can predict a fracture. And most "SFI certified" products do not meet SFI's definition of a H&N restraint.

Aside from that, the spec is perfect.

Gregg (Isaac) Baker

Safe Drives

Hello all,

This is my first post on your fine forum. I've lurked for a while though and found this thread linked from the Leatt Brace website. I am the owner of a company called Safe Drives LLC. My company specializes in retailing only auto safety related products. Wherever possible we try to offer only tested and certified safety products. A head and Neck Restraint is a product that meets that criteria.

SFI 38.1 exists as a standard and many other devices have failed to obtain the SFI 38.1 certification.

Mr. Baker, do you know of any new spec for H&N Restraints on the horizon?

Best regards,

Charles Buren
Safe Drives LLC
www.safedrives.com
cburen at safedrives.com
877-739-1713 toll free

gbaker

But no one cares. It's not a standard, it's just a sicker for a suboptimal design. FIA doesn't care, NASCAR doesn't care, IRL doesn't care, CART doesn't care, SCCA doesn't care, PCA doesn't care...

As a vendor, what do you think your liability will be when you sell a driver a so-so product just because it has a sticker on it?

Gregg Baker, P.E.
Isaac, LLC

gbaker

The word on the street after PRI is that the non-Leatt manufacturers want to reduce the allowed Fz load value to 2,500N. Leatt wasn't there so it is going to ballot.

How does this affect things? The Leatt Moto-R tests with Fz values in the 2,600N-2,700N range. If the proposal is adopted the Leatt will no longer be "SFI certified".

Gregg Baker, P.E.
Isaac, LLC