Ian Frearson wrote:
>
> My Spitfire came with a pad-less rollbar installed when I bought it, and
> even with no pad it was very "in the way". I immediately removed it. I'm not
> a safety expert, but the impression I got was that (in the case of a
> Spitfire) although the rollbar might be beneficial if you actually rolled
> the car, it has the potential to cause some very serious head trauma, pad or
> no pad. My experience...I'm sure there will be many opinions on this topic.
I spent some time racing a car in the NASCAR Sportsman class on a
NASCAR-sanctioned track, and, consequently, did a lot of research into
available materials and equipment. Padding for roll bars is much
misunderstood. Typically, uninformed racers put the nearest foam sheet
on roll bars and taped it in place, and, in an accident, found the
padding to be substandard. That was not the fault of padding, per se,
but rather, of the choice of padding of the racer.
The best foam for roll bar impact protection is both thick and dense. As
with any material which must absorb impact, the foam must actually
absorb forces, rather than simply compress in the process of impact.
Ordinary foam is high in empty or air-filled cells, which compress
easily--that means, on heavy impact, that the foam reduces its volume to
almost nothing and allows impact with the metal of the roll bar,
resulting in an increased chance of injury.
Denser foam, with some resistance to compression, is far more useful in
absorbing brain-changing impact. (!) It's softer than the metal
underneath it, but has, like the properties of a unibody car,
progressive crush properties to _absorb_ the impact energy as it
deforms, thus preventing serious injury, even in sport (rather than
racing) driving in the event of an accident.
All foam padding is not alike.
Cheers.
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