On Sep 16, 8:20*am, a wrote:
On Sep 15, 6:09*pm, "Viperdoc" wrote:

The thread on brakes raised a question from the past- why nitrogen in the
tires of big jets and heavies? Air is around 78% nitrogen anyway, and the
coefficient of expansion of the remaining 20% that's oxygen can't make that
much difference in volume.

Why not just use dry air? I couldn't imagine that dry air or dry nitrogen
could make that much difference in corrosion, either.

I seem to recall someone giving me the rationale for this a long time ago,
but also seem to remember thinking it didn't make that much sense at the
time.

The legend is that *the oxygen is reacting with the rubber. Even
though compressed air has the same fraction of oxygen as does the
atmosphere, the fact that it's compressed, it's been argued, increases
its reactivity. I can't validate the legend.

Thats is not a legend its a fact rubber is very prone to oxidation
which is why it contains chemical antioxidants, and the reactivity
will be proportional to the concentration , ie pressure of the
oxygen. I am not however saying that is the only reason otherwise why
dont we put nitrogen in our car tyres.
Terry