Michelin AirStop isn't

[kentb]

Originally Posted by airguy

Nitrogen will be interfered with more effectively than the oxygen by the carbon-sulfur bonds in the rubber, significantly slowing it's elution through the tube and tire. Pure nitrogen will still lose pressure in a tire, but slower than straight compressed air. I was told recently by an A&P servicing a Mitsubishi Diamond (now BeechJet 400A) tire that the main reason nitrogen is used is to make sure it's completely dry to limit microbial action, and so there is no oxygen in the tube to slowly oxidize the inner surface, which causes cracking.

If the O2 leaks out faster then after filling up with air a couple of time the N2 should raize from 78% to 99%.

Kent

[avpro56]

I've had very good experience with my Michelin Air Stop tubes. Same with my hangar mate, topping off the tires is not required for months. I will say that I recommended these tubes to my neighbor for his Grumman Tiger, and he did not notice as much difference, but there was an improvement. We are using shop air through a dryer, not nitrogen.

This year I have changed to the other brand of Leak Stop tubes, simply because they were available from the dealer where I bought my new tires.

[Mark Burns]

I was taught in A&P school (a long time ago) that nitrogen was more temperature stable. And that it should be used in struts and tires for that reason if it's available.

And by stable I mean it expands and contracts less with temperature changes.

Mark

[Captain_John]

Hey, I just googled up tires and nitrogen and it seems that there are ALOTTA LINKS for stuff!

My buddy was on a carrier and says that all the warbirds do it as a standard practice!

I am sure it can't hurt any!

Check out this link for cars.

Google some yourself and check it out!

CJ

[mannanj]

Guys:

I guess I must be the odd ball here. Aired mine up about a year before first flight. Six months later after 60 hrs. of flying they still had 30 psi, just what I put in 18 months earlier.

Must be my soft landings!!!!!!!!!

[N733JJ]

Originally Posted by Mark Burns

I was taught in A&P school (a long time ago) that nitrogen was more temperature stable. And that it should be used in struts and tires for that reason if it's available.

And by stable I mean it expands and contracts less with temperature changes.

Mark

This has always been my understanding of why it is used on many aircraft as well as race cars. However, I have noticed that with airstoppers and local Poughkeepsie air, my tires only loose a couple pounds when the weather turns cold.

Scott A. Jordan
N733JJ

[AlexPeterson]

Originally Posted by Mark Burns

I was taught in A&P school (a long time ago) that nitrogen was more temperature stable. And that it should be used in struts and tires for that reason if it's available.

And by stable I mean it expands and contracts less with temperature changes.

Mark

Unfortunately, this is not true. The pressure changes in your tires due to temperature changes would be identical with any gas, at least is any measurable sense.

There might be stability in using pure nitrogen in the sense that some of the oxygen in normal air may react (combine chemically) with compounds in the rubber in the innertube, and hence not contribute to the pressure any longer.

[Low Pass]

Originally Posted by AlexPeterson

Unfortunately, this is not true. The pressure changes in your tires due to temperature changes would be identical with any gas, at least is any measurable sense.

There might be stability in using pure nitrogen in the sense that some of the oxygen in normal air may react (combine chemically) with compounds in the rubber in the innertube, and hence not contribute to the pressure any longer.

Unless air containing water vapor was used to fill the tire and was condensing. Then I could envision loosing significant pressure as compared to a dry, non condensing gas.

[Jconard]

When I raced, we did fill the tires with nitrogen, and Alex is correct that the iflation changes, attributable solely to the gases changing temperature, are not measurably different.

But, the reality is that compressed air always contains some moisture and it is this content which causes wild changes based on temperature changes.

The feeling of the racing teams was that by using nitrogen right from the bottle, we could avoid these issues. Some teams would mount the tire, use nitrogen to set the bead, then drawn a vaccum to remove all gas in the sealed tire, and then refill, with the nitrogen.

As a driver I can tell you that it made the tire pressure much more stable, and in the aero cars, it was a real help, as they are pitch critical for downforce.

[RVadmirer]

I ordered a 2.80/2.50-4 airstop tube from AC Spruce and it was labeled as such on the bag but is made by Cheng Shin. Has anybody had any experience with these? If Michelin "isn't" what can be expected from Cheng Shin?