Motocross neck brace for car racing - why not?

[V8ish]

Just wondered if anyone has any thoughts on this?

I have a Leatt DBX brace, like this: https://www.google.co.uk/search?q=leatt+dbx+brace&...

Does anyone know if there is any reason why I cant use it for car racing with my full face. Surely it does the same job?

Thanks

[HustleRussell]

Firstly I expect it isn't shaped to work with a head restraint, so normally seated you might find it interferes annoyingly with the seat/head rest
Secondly it doesn't look very fireproof to me
Thirdly I wouldn't be at all surprised if when normally seated in a car seat it would interfere with your helmet and that would be annoying and/or restrictive.

[V8ish]

Fair point, cheers. Guess I will just have to get all my gear on and just sit the car.

If i can overcome these issues are there any other reasons/suggestions?

Thanks

[EDLT]

The neck injuries that prevents aren't the ones that racing drivers can suffer. As far as I know, the problem in racing is when a car hits a wall the driver's head is pulled forwards and up. Which is the movement the HANS device prevents.

I wonder if putting a little more give in the harnesses would help, inertia reel seatbelts seem to work fine in road cars.

[LocoBlade]

The 6 point harness would have to strap you in with that sandwiched in between or the belts would go around it and not tighten properly, either way that wouldn't be good.

Edited by LocoBlade on Thursday 20th December 13:15

[HustleRussell]

EDLT said:

The neck injuries that prevents aren't the ones that racing drivers can suffer. As far as I know, the problem in racing is when a car hits a wall the driver's head is pulled forwards and up. Which is the movement the HANS device prevents.

I wonder if putting a little more give in the harnesses would help, inertia reel seatbelts seem to work fine in road cars.

Absolutely right, hyperextension of the neck is the problem and causes neck and skull fractures. However any neck brace which stops the head snapping forward (as this one would) is an improvent on nothing at all, so long as it doesn't limit neck movement and therefore all-round visability. As you say, HANS is the way to go.
However the bit about slack in the harnesses- strongly disagree! any slack at all is undesirable because it simply allows the mass of your head/neck/upper body to accelerate forward unabated before being suddenly restrained. The tighter the harnesses, the less acceleration, the less forceful the deceleration. The reason inertia reels are used in cars is because they don't have to be constantly adjusted and they allow some movement for comfort. Full harnesses, worn tight, are safer than inertia reels in pretty much any circumstance as far as I understand.

ETA: the webbing used for harnesses is designed to yield slighly to control the deceleration. However the point of them is that you wear them very tight and they begin to restrain your forward motion as early as possible
Another thing to consider is that reducing the weight of the mass you're trying to decelerate, particularly on the head, will reduce the amount of strain in the neck- which is why a lightweight helmet, 6-point harnesses and a HANS device is pretty much the ultimate. This is why the F1 guys use them.

Edited by HustleRussell on Thursday 20th December 13:35

[Captain Muppet]

EDLT said:

I wonder if putting a little more give in the harnesses would help, inertia reel seatbelts seem to work fine in road cars.

My spine was fractured by an inertia reel seatbelt in a road car.

With a 4 point harness the top of your body can't move, so it's just the inertia of your head thats avaialable to generate spinal injuries, not the inertia of your head, chest and arms.

[EDLT]

Captain Muppet said:

EDLT said:

I wonder if putting a little more give in the harnesses would help, inertia reel seatbelts seem to work fine in road cars.

My spine was fractured by an inertia reel seatbelt in a road car.

With a 4 point harness the top of your body can't move, so it's just the inertia of your head thats avaialable to generate spinal injuries, not the inertia of your head, chest and arms.

How, I thought inertia reels allowed your body to decelerate more slowly?

[LocoBlade]

Surely inertia reels still lock solid in a crash, but only after they've let your body accelerate forward a few inches.

[HustleRussell]

EDLT said:

How, I thought inertia reels allowed your body to decelerate more slowly?

No, inertia reel belts allow you to move normally and comfortably until an impact occurs, at which point they lock almost immediately using a intertia clutch mechanism. The job of the belt is to restrain forward motion. They're quite effective. The problem here is the 'almost' immediately bit- the belt is still quite slack and the body is still able to accelerate forwards for a period.
The solution is pre-tensioners and deformable anchorage points. The anchorage points are the bit which allows the body to decelerate more slowly.

[MrKipling43]

Some of what you're saying here isn't entirely correct.

HustleRussell said:

However the bit about slack in the harnesses- strongly disagree! any slack at all is undesirable because it simply allows the mass of your head/neck/upper body to accelerate forward unabated before being suddenly restrained. The tighter the harnesses, the less acceleration, the less forceful the deceleration. The reason inertia reels are used in cars is because they don't have to be constantly adjusted and they allow some movement for comfort. Full harnesses, worn tight, are safer than inertia reels in pretty much any circumstance as far as I understand.

Harnesses are designed to hold you tight in the car so you're not having to brace against the steering wheel or pedals when you're driving quickly and to prevent submarining and flying out of the belt during a whopper. But a tighter harness won't reduce deceleration, but increase the effect of it. Remember, energy can't be destroyed or created, only moved from one place to another. With that in mind, energy will move the bits of you that can move - head, leags, arms etc. Theoretically, a looser harness would actually dissipate the energy in a crash, but only because you would naturally decelerate before you were restrained - increasing the distance over which deceleration occurs, which is the absolute key to minimising injury. Also you'd be moving around while driving (bad) and you might come out of the harness/whack bits of the cockpit during a crash. How quickly you are restrained has little bearing on how badly you'll be injured - the energy in your body is that same no matter what.

In a road car. the 'lap and shoulder' belt is designed so that the unrestrained part of your body rotates over the belt, which again increases the distance over which deceleration occurs, which reduces the risk of injury the neck and back. Every safety measure in every car (race or road) has this concept at its heart: see crumple zones for reference.

HANS devices were developed because harnesses don't allow for this. All the energy goes in to your neck. Bad.

You'd be amazed at how stretchy a seat belt is as well. Even race harness will stretch about 10cm for every 1m of material

Check it out in this video: http://www.youtube.com/watch?v=_K-nQIuiatw

[marshall100]

V8ish said:

Just wondered if anyone has any thoughts on this?

I have a Leatt DBX brace, like this: https://www.google.co.uk/search?q=leatt+dbx+brace&...

Does anyone know if there is any reason why I cant use it for car racing with my full face. Surely it does the same job?

Thanks

Don't these just break your collar bone when you have an off instead? that's my understanding and the reason why I stick to a simple neck collar when racing my quad.