Replacing innertubes without replacing tires?

Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

wrote in message
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Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

"Mike Noel" wrote in message
. ..
I don't know the practical aspects of N2 v O2 in modern tubes, but the
partial pressure of O2 in a tire inflated to 30 psi is 3x that on the
outside of the tube. If anything in the rubber tended to oxidize, it
would
oxidize significantly faster at the higher O2 partial pressure.
It may not be a practical problem in tubes, but I'll bet it makes a
difference in a strut (1000 psi?)

Is anybody suggesting the use of O2?

How do you not use O2 if you use air?


Well if we are going to call using "air" using O2 we might as well call it
using N2. There is a lot more N than O.

Nobody but you used the phrase "use O2", notice the phrase "partial pressure"
in the original post.

--
Jim Pennino

Remove .spam.sux to reply.

wrote in message
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Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

wrote in message
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Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

"Mike Noel" wrote in message
. ..
I don't know the practical aspects of N2 v O2 in modern tubes, but
the
partial pressure of O2 in a tire inflated to 30 psi is 3x that on the
outside of the tube. If anything in the rubber tended to oxidize, it
would
oxidize significantly faster at the higher O2 partial pressure.
It may not be a practical problem in tubes, but I'll bet it makes a
difference in a strut (1000 psi?)

Is anybody suggesting the use of O2?

How do you not use O2 if you use air?


Well if we are going to call using "air" using O2 we might as well call
it
using N2. There is a lot more N than O.

Nobody but you used the phrase "use O2", notice the phrase "partial
pressure"
in the original post.

Read the first sentence in Mikes post and notice the phrase "I don't know
the practical aspects of N2 v O2 in modern tubes,..."

Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

wrote in message
news
Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

wrote in message
news Gig 601XL Builder wrDOTgiaconaATcox.net wrote:

"Mike Noel" wrote in message
. ..
I don't know the practical aspects of N2 v O2 in modern tubes, but
the
partial pressure of O2 in a tire inflated to 30 psi is 3x that on the
outside of the tube. If anything in the rubber tended to oxidize, it
would
oxidize significantly faster at the higher O2 partial pressure.
It may not be a practical problem in tubes, but I'll bet it makes a
difference in a strut (1000 psi?)

Is anybody suggesting the use of O2?

How do you not use O2 if you use air?


Well if we are going to call using "air" using O2 we might as well call
it
using N2. There is a lot more N than O.

Nobody but you used the phrase "use O2", notice the phrase "partial
pressure"
in the original post.

Read the first sentence in Mikes post and notice the phrase "I don't know
the practical aspects of N2 v O2 in modern tubes,..."

Keep reading; this is followed by "...but the partial pressure of O2 in
a tire...".

From http://en.wikipedia.org/wiki/Partial_pressure

"In a mixture of ideal gases, each gas has a partial pressure which is
the pressure which the gas would have if it alone occupied the volume."

Clearly, the original poster was referring to a mixture of gases that
contains O2, i.e. air.

--
Jim Pennino

Remove .spam.sux to reply.

I always replaced tires and tubes together. For the additional $30 for a
new tube, I always thought it was false economy to reuse them. As some
have acknowledged, the tubes stretch and may fold upon reuse. I usually
see cracking around the valve stem on a used tube. Perhaps reuse would
be an option if we flew 250 hours a year and wore out tires sooner. But
we usually have tires for 4 years or so. By then, I usually see the
valve stem starting to crack and the sidewalls cracking on the tires.

It seems like cheap insurance. But, others swear by reusing tubes. This
is a pretty good case of how different people will accept differing
degrees of maintenance. Absent any Advisory Circular or maintenance
manual prohibition against reusing tubes, it is "legal" to do so.

Nitrogen in the tires? I don't even use nitrogen in the struts.

Good Luck,
Mike

On Thu, 26 Oct 2006 14:30:56 -0500, Ben Jackson wrote:

I picked up a set of airstop-style tubes in my last AC Spruce order. I
was reviewing tire maintenance procedures and saw a recommendation that
you not re-use innertubes because they set slightly stretched and there's
a risk of pinching or folding them when they are reinstalled.

So, considering these tubes are new and my tires are decidedly NOT, would
I be "wasting" the new tubes on the old tires, or would it be okay to
reuse them on a future new tire?

ben reusing the tubes is not a froblem if they are in good condition
and not perished.

you can save yourself a lot of grief in the long run if you replace
the schrader valves with each new tyre. use aviation high pressure
shraders and you should have no problems at all.
the valves do wear out and if the tyre goes flat everytime the valve
is at the bottom of the hub you have a worn out schrader core.

Stealth Pilot

I wish I could be like you guys and be able to say I never had a flat due to
a worn tube.
Unfortunately, I discovered how difficult it is to taxi with a flat. Dang
those flight school planes.

Kent Felkins

On 2006-11-05, Fly wrote:
Unfortunately, I discovered how difficult it is to taxi with a flat. Dang
those flight school planes.

On a slightly related note, I always saw flat spots on the tires of
rental airplanes and I wondered if I'd been responsible for any of them.
Now that I've had the same set of tires for hundreds of landings I know
it must be harder than I thought to flat-spot a tire.

--
Ben Jackson AD7GD

http://www.ben.com/

On Sun, 05 Nov 2006 14:35:48 -0600, Ben Jackson wrote:

On 2006-11-05, Fly wrote:
Unfortunately, I discovered how difficult it is to taxi with a flat. Dang
those flight school planes.

On a slightly related note, I always saw flat spots on the tires of
rental airplanes and I wondered if I'd been responsible for any of them.
Now that I've had the same set of tires for hundreds of landings I know
it must be harder than I thought to flat-spot a tire.

no....
the tyres are out of balance.
after takeoff when the wheel finally spins to a stop the heavy part of
the wheel naturally points down. this means that the same part of the
tyre actually bears the wear of touchdown as the tyre is spun up to
landing speed.
thats why there are flat spots.

Stealth Pilot

Ben Jackson wrote:

On a slightly related note, I always saw flat spots on the tires of
rental airplanes and I wondered if I'd been responsible for any of them.
Now that I've had the same set of tires for hundreds of landings I know
it must be harder than I thought to flat-spot a tire.

It must be easy to do in a Mooney. A club I belonged to for a while was
constantly having flat-spotted mains on their Mooneys, and I've also
seen it on the Mooney I own with partners. I may have been responsible
for some of that when I first joined the partnership. I started being
more careful about braking and the flat-spots haven't come back. I get
smoother landings if I don't land in a full stall, and all the weight
doesn't come on the wheels 'til you've slowed down a bit. If you start
braking too early it's easy to lock up the mains and not feel it.