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Are we going to see nitrogen used in tires soon? I know it has been around for a while in other industries and I heard it is coming for public use in cars.

Is this going to be good for motorcycles or are there drawbacks. All I know about it is that the pressure won't change as tires heat up and cool down.
 
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Re: Nitrogen and tires. (themagicalswitch)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by themagicalswitch »</TD></TR><TR><TD CLASS="quote">Are we going to see nitrogen used in tires soon? I know it has been around for a while in other industries and I heard it is coming for public use in cars.

Is this going to be good for motorcycles or are there drawbacks. All I know about it is that the pressure won't change as tires heat up and cool down.</TD></TR></TABLE>

Pressure still changes – I don’t know if there is a gas that doesn’t expand with heat, but since it is dry, it the change will be more predictable.
But unless you run a vacuum before you put the nitrogen in, there will still be a small amount of humid air in the tire (1 atmosphere's worth)
 
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Re: Nitrogen and tires. (Eddie)

Eddie, Is it true that nitrogen leaks much less than air? I saw a tire program that
states more and more tire stores carry nitrogen and for $20 bucks?? they will hook it up.
 
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Re: Nitrogen and tires. (STRATUS749)

Air, good ole plain air, is ~ 78% nitrogen. Unless you're racing, you don't need to worry about the difference in thermal pressure changes induced by running conventional air v. nitrogen.
If you're convinced you've just got to run it, you should purge and fill the tire at least twice to get all the air (ie., moisture) out that may have cavitated inside the wheel and then refill w/ nitrogen; to really do it properly, you should have 2 valves on the tire - one to pump out the old air while you refill w/ new through the other.
And no, nitrogen won't leak any slower.
 
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Re: Nitrogen and tires. (themagicalswitch)

My old man just bought an 05' Chevy Tahoe. Before he took delivery, they put custom rims and tires on it at the dealer for him. He asked them why they put green valve stems on it and they explained that they use nitrogen to fill all of their new tires.


I wonder if it has anything to do with the air pressure tire sensors built into the new vehicles?


Modified by CaliDuc at 10:28 AM 6/7/2005
 
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Re: Nitrogen and tires. (hubert)

Thanks for the info Hubert!


Modified by STRATUS749 at 11:15 AM 6/7/2005
 
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Re: Nitrogen and tires. (STRATUS749)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by STRATUS749 »</TD></TR><TR><TD CLASS="quote"> Eddie, Is it true that nitrogen leaks much less than air? I saw a tire program that
states more and more tire stores carry nitrogen and for $20 bucks?? they will hook it up.</TD></TR></TABLE>

I just found this that says nitrogen leaks 3 times more slowly than air. From here http://www.alltiresupply.com/a....html

"Nitrogen is a dry, inert gas used to inflated airplane tires, off-road truck tires, military vehicle tires, and race car tires for improved performance. Oxygen is compressed air permeates through the tire wall, oxygen oxidizes the rubber compounds in the tire, causing under inflation and deteriorated rubber. Dry nitrogen will prevent auto-ignition, will not corrode rims, and helps the tire to run cooler.

Nitrogen -- a dry, inert gas used by racing professionals and the U.S. military to inflate racecar tires and military vehicles, respectively -- leaks through a tire's rubber walls three times more slowly than oxygen. As a result, tires filled with high-quality nitrogen delivered by IR's system stay inflated longer, which allows them to grip the road better and provide greater control in all weather conditions."
 
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Re: Nitrogen and tires. (themagicalswitch)

I don't see how it leaks through more slowly; that would imply that N2 is a larger molecule than the heteromolecular mixture that is regular air; seeing as how regular air is mostly N2, I'd like to see data backing up that statment before I believe it.
 
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Re: Nitrogen and tires. (hubert)

Hey Hubert, I searched a little more and found this, some of the sources are listed:
http://ezinearticles.com/?Sell...38142

Nitrogen In Tires

Here are a few other benefits of using Nitrogen in tires:

[1] Nitrogen is denser than Oxygen: This means the larger molecules escape less easily from tires resulting in a more gradual loss of pressure over time. According to the Michelin Tire Manual, a tire that is inflated with Nitrogen loses its pressure 3 times slower than if it were inflated with air.

[2] Nitrogen is moisture free: Pure Nitrogen inflated tires experience less steel belt and rubber degradation. Nitrogen use also reduces valve and wheel corrosion.

[3] Nitrogen provides longer tire life: Nitrogen inflated tire run cooler and require less maintenance according to the Goodyear application bulletin.

[4] Nitrogen is non-flammable: Nitrogen technology has been used in aircraft, military and race car technology for over thirty years.
 
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Re: Nitrogen and tires. (themagicalswitch)

Well, I have to respectfully disagree. In it's diatomic state, N2 has a molecular weight of 14g/mol and oxygen, O2, is 16g/mol. The oxygen molecule has more mass. A fact that is backed up by the following table, showing densities of all the Period 2 elements of the periodic table. Moreover, as move accross and down the periodic table, the size of the atom grows larger; oxygen is to the right of nitrogen.




Modified by hubert at 12:49 PM 6/7/2005
 
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Re: Nitrogen and tires. (hubert)

--edited last post--

Interesting about the densities. I wonder why they have nitrogen listed as more dense than oxygen?

I found some numbers that back up your chart.
O2- 1.429 kg/m^3
N2- 1.2506 kg/m^3

I wonder why everything I read says nitrogen is more dense than oxygen when it apparently isn't.

Had to reword this as it didn't make sense--
I wonder if moisture content has anything to do with it. Since oxygen has moisture in it - if it were to be quite moist it would have a heavier mass, but greater volume as well and density=mass/volume, so the density could lower. Is it possible for oxygen inside the tire to become more moist?
 
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Re: Nitrogen and tires. (themagicalswitch)

Since density doesn't seem to be the point, do you think that the fact that: A tire filled with oxygen will cause the oxidation of the rubber in the tire over time and effectively weaken the molecular structure of the rubber. - is why the nitrogen filled tires are claimed to hold pressure better?
 
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Re: Nitrogen and tires. (themagicalswitch)

I got it. It is a matter of density, but it's not a matter of density at ambient temp. As the tire heats, the air with more water in it will become less dense and a gas w/ less moisture will become (is) more dense. At eq. O2 nas a higher density but if you heat air (a mixture including water) and N2, the O2 will become less dense on account of vaporization.
 
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Re: Nitrogen and tires. (themagicalswitch)

Back to simpleness
you molecular mathmeticians.
why is nitrogen only used in nascars? if prolonged deteriorzation is not an issue?
 
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Re: Nitrogen and tires. (STRATUS749)

Because nitrogen atoms in nitrogen gas (their diatmoic state) share a triple bond which makes either atom in the pair much less reactive on account of the strength of the triple bond. Oxygen, on the other hand, has a double bond and is therefore more reactive. Oxygen is also more electronegative than Nitrogen.
 
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Re: Nitrogen and tires. (STRATUS749)

The problem with using air is that it's a mixture of gases and water vapor that doesn't behave like a perfect gas under Boyle's Law. In particular, the water vapor component makes the relationship between pressure and temperature non-linear so the correct cold tire pressure will be different when you use air on different days having a different relative humidity.

Using dry nitrogen in tires for the track removes this variable and makes it easier to develop a consistent suspension set-up.
 
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Re: Nitrogen and tires. (Shazaam!)

Hubert,shazaam,
Thanks for the clarifaction!
 
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Re: Nitrogen and tires. (STRATUS749)

If oxygen leaks faster than nitrogen, and air is 78% Nitrogen.....then when you lose pressure, 3/4 of that is oxygen. So now you have greater than 78% nitrogen. Then you put in a couple more PSI with air....and the oxygen leaks out over time...leaving you with yet a higher percentage of nitrogen. and on and on.
 
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Re: Nitrogen and tires. (Buckelew)

All I know is that at the level I ride, I could fill the tires with the gas from my ass (if I could get 31psi) and I couldn't tell the difference.
 
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