wow! john you run with pressures that high? the sports racer runs 10 F. &
15-18 R.! your VEE is about the same "wet" weight? around 800lbs w/o
home from richmond! what a nasty drive (D.C / Balt. area added over 3 hrs.
to my drive home! ) congestion and accidents , the likes i've never seen
> [Original Message]
> From: John D. Caffrey <email@example.com>
> To: Geoff Branch <firstname.lastname@example.org>
> Cc: <email@example.com>; Robert E. Shlafer <firstname.lastname@example.org>
> Date: 8/25/2006 8:44:37 AM
> Subject: Re: Helium in Tires
> Water vapor is indeed the main reason to NOT use compressed air in
> tires for critical use. I can only speak from my racing experience, but
> when we set our tire pressures, it is only a starting point and we must
> fine tune from there. You see what is important is the hot pressures,
> and how much the pressure builds from the cold setting. My tires like
> to be at 26 psi at operating temperature, more than that and they get
> to sliding too much and building even more heat, and sometimes when
> using air the hot pressure will be hard to control and gain as much as
> 6 psi during the race. I believe the reasons are the same for aviation
> where if using air, the intense heat generated during touch down will
> send the pressures soaring, adding to the risk of blowouts and wheel
> Fogelsville, PA
> Geoff Branch wrote:
> >Charles and Boyles gas laws say that the composition of the gas doesn't
> >matter.....provided it's pure gas....throw a little water vapor in and
> >bets are off.
> >One of the reasons nitrogen is used in aviation is that it comes from a
> >bottle so is DRY.
> >Of course it's more expensive than compressed air which is another
> reason to
> >use it the military and aviation bidness!!
> >Geoff Branch