Nitrogen in tires?

[yechave]

Just wondered if anyone uses Nitrogen in their tires. I have switched some time ago for my van, and it has never needed inflation between yearly checks. Like to be as confident with the bike. Cost is only $5 per tire. Thanks!

[John Ranalletta]

I've started using Great Stuff. The ride's a little rough, but flats are a thing of the past.

 

[Dick_at_Lake_Tahoe_NV]

I've started using Great Stuff. The ride's a little rough, but flats are a thing of the past.

 

 

That's a great idea--do you put it on the inside or the outside of the tire.

 

BTW, Air is already 80% Nitrogen, I think the main advantage to using "Dry Nitrogen" is that's it's "Dry"--no water vapor.

[T__]

Just wondered if anyone uses Nitrogen in their tires. I have switched some time ago for my van, and it has never needed inflation between yearly checks. Like to be as confident with the bike. Cost is only $5 per tire. Thanks!

 

 

Wayne, been using Nitrogen in ALL my pneumatic tires since the early 1950’s..

Not at 100% though..

 

It usually starts out at about 78% but if it stays in the tire & all the other gasses like oxygen leak out like the so called experts say then I must be at close to 100% by now..

 

 

Twisty

[John Ranalletta]

That's a great idea--do you put it on the inside or the outside of the tire.

Hey, what's so damn funny? It's harder to get it all inside the tire than you might think.

 

[swfraley]

This nitrogen-filled tire thing is, IMHO, a boondoggle. They'll tell you that temperature changes cause less pressure change in a nitrogen-filled tire. That's not true, because of the Ideal Gas Equation: PV=nRT, where P=Pressure, V=Volume, n=number of moles of gas, R=Constant I Can't Remember, and T=Temperature.

 

What's more, when looking at Pressure and Volume changes in response to temperature changes, the relationship is:

(P1V1)/T1 = (P2V2)/T2. It doesn't matter what the gas is.

 

They'll also say, "They use nitrogen in NASCAR tires. There must be a good reason for that." There is: Fire prevention.

 

As others have said, nitrogen in tires is good, but 78% is enough.

[tomk99r11]

Uh Oh! Here comes the scientific explanation which will surely be followed by the contrary scientific explanation which will be followed by the ones who use Nitrogen in tires because.........and "got 50k on their tires. And, so it goes!

[ShovelStrokeEd]

SWFarley has it exactly right. Even water vapor in the tire will do little to effect the pressure vs temperature relationship. Mitch or whatever he is calling himself this week put this whole thing to bed awhile back. Liquid water in the tire is another matter, however, so just be careful about the amount of tire lube used when mounting.

 

BTW, the other good reason for using Nitrogen in Nascar is that they don't have to haul a big ass compressor down to the pit wall. They already have multiple tanks of dry Nitrogen around for running those high speed air guns. I used to use it on my race bike for the same reason. Convenience as I just carried a small tank on my starter cart to fill my air shifter reservoir and adjust rear tire pressure prior to making a run. A race slick leaks air at a prodigious rate and, when you only have 4 lbs of air in the tire, 1/2 a lb can make a major difference.

[Joe Frickin' Friday]

Mitch or whatever he is calling himself this week...

 

Is this the Potato farm?

 

...put this whole thing to bed awhile back.

 

Actually I've put it on my website now:

 

http://mywebpages.comcast.net/prestondrake/N2_for_tires_FAQ.htm

[steve.foote]

I like to use a 78% nitrogen mix inside AND outside my tires. This keeps me balanced, improves my looks and may even lower my colesterol. YMMV, but you'll probably feel better regardless.

[Heck]

Just wondered if anyone uses Nitrogen in their tires. I have switched some time ago for my van, and it has never needed inflation between yearly checks. Like to be as confident with the bike. Cost is only $5 per tire. Thanks!

 

That $5 buys you a little green valve cap that can be used to start esoteric conversations at the grocery store, gas station, or your local library. Other than that, not much advantage.... YMMV, (but not because of the Nitrogen..)

[Wyn]

UltraSeal, same benifits plus no deflation if you pick up a nail or screw.

[bmurphypdx]

I use nitrogen in my tires and my final drive hasn't failed and my bike doesn't burn oil and I hardly get any wind noise in my helmet speakers and my dentist said no cavities again this year! That nitrogen is good stuff!!

[Bob Palin]

I put pure oxygen in my tyres, it makes it so much easier to find the leak when I get a flat...

[RFW]

Just wondered if anyone uses Nitrogen in their tires. I have switched some time ago for my van, and it has never needed inflation between yearly checks. Like to be as confident with the bike. Cost is only $5 per tire. Thanks!

There is basically no benefit at all. Not surprising since your tires are ALREADY filled with 78% Nitrogen. It's called "air". None of the arguments in favor of replaing the remaining 22% (mainly oxygen) to get 100% nitrogen, have any significant scientific basis.

 

It is claimed that tire leakage will be reduced. Total rubbish. Nitrogen and oxygen have very similar molecular sizes, and leak through rubber at nearly the same rates. If it really WERE true that the oxygen in your tires was leaking a lot faster, then after half a dozen "top ups" with air, the nitrogen concentration would have increased to nearly 100%, and you would not need to squander your money to fill with nitrogen.

 

Think about it... you first fill with air, then all the O2 leaks out, so the tire has 78% of its original content that is pure N2. Now you fill that remaining 22% of that with air again. Well, 78% of that last 22% you just put in, is N2, so now the tire has 78% + (78% of the remaining 22%) = 95.16% Nitrogen inside! Repeat this a few more times and you have 99+% of the tire filled with nitrogen!

 

So you would get a pure nitrogen fill for free! Why would you PAY for something you could get free??

 

But of course this does not happen, BECAUSE THE BS ABOUT NITROGEN NOT LEAKING IS JUST THAT.... BS!

 

It is claimed that using nitrogen will eliminate degradation of the rubber. This is a solution looking for a problem! As anyone can see when removing a worn-out tire, that was filled with that nasty old "air", the rubber inside is still in perfect condition! So where's the problem here?

 

It is claimed that nitrogen filled tires run cooler. That is pure fiction and is unsupported by any scientific principle.

 

The only possible benefit is the elimination of water vapor in the event that humid air was used to fill a tire. Under some conditions, condensation may result, causing a small reduction of tire pressure. But even this is a stretch!

 

It is claimed that race cars use it, so it MUST be good! The main reason they use the stuff is because it is a lot more convenient to have a small high pressure bottle of nitrogen, than to lug around an air compressor.

 

In short, the claims made for the supposed benefits of N2, really insult the intelligence of any thinking person.

[ShovelStrokeEd]

Bob,

You do realize that that series can only approach 100% and never actually get there. Just spoofing a bit.

 

BTW, weren't both Pam Anderson and Dorothy Stratten from Vancouver? I gotta get up there one of these days. Sounds like the islands and the bay area aren't the only "scenic" attractions to the area.

[Dick_at_Lake_Tahoe_NV]

I put Helium in my tires and it reduced my bike's weight by 38-grams! Not only that but it reduced the rotational inertia of my wheels.

[USAF1]

Because it's colored differently than the oxygen on the outside, right??

 

Pat

[Bob Palin]

Because it's colored differently than the oxygen on the outside, right??

 

Pat

I was thinking more along these lines

 

[UberXY]

[

It is claimed that race cars use it, so it MUST be good! The main reason they use the stuff is because it is a lot more convenient to have a small high pressure bottle of nitrogen, than to lug around an air compressor.

 

 

It's just as easy to carry a bottle of compressed air as it is carry a bottle of compressed nitrogen. Most amateur racers, like in SCCA, use air tanks to the pits.

 

The reason we use it in race cars is that pure nitrogen has a coefficient of expansion of 0.8, as opposed to 1.0 for air. This means that as the tire heats up the tire pressure does not rise as much. When the tire pressure rises it changes the circumference of the tire, which affects the ride height. When you are dealing with multimillion dollar formula cars with very low ride heights, it makes a difference. It also changes the gearing, as the gear ratios are calculated using tire circumference as a constant. Increased tire pressure also changes the spring rates.

 

That said, putting nitrogen in street tires is a waste of time and money.

[swfraley]

Coefficients of expansion are not applicable to gases, only liquids and solids.

[Joe Frickin' Friday]

It is claimed that tire leakage will be reduced. Total rubbish. Nitrogen and oxygen have very similar molecular sizes, and leak through rubber at nearly the same rates.

 

This is not true.

 

The long answer is here.

 

The short answer is that N2 leaks through butyl rubber (the material they line the inside of tubeless tires with to reduce overall gas permeability) about 4 times slower than oxygen at the same pressure. For air at the same pressure, N2 leaks out about 1.6 times more slowly. Which doesn't quite live up to the advertising hype, but it's still significantly different.

 

If it really WERE true that the oxygen in your tires was leaking a lot faster, then after half a dozen "top ups" with air, the nitrogen concentration would have increased to nearly 100%, and you would not need to squander your money to fill with nitrogen.

 

Agreed.

[RFW]

Bob,

You do realize that that series can only approach 100% and never actually get there. Just spoofing a bit.

Yes, of course. Not unlike the reasoning behind the half life of a radioactive isotope which in theory can also never quite totally decay.

 

BTW, weren't both Pam Anderson and Dorothy Stratten from Vancouver? I gotta get up there one of these days. Sounds like the islands and the bay area aren't the only "scenic" attractions to the area.

Yup, both were from here. But as much as the blond bimbo comment in my sig may be appropriate to at least one of those you mentioned, I was really referring to the city itself that is so full of itself, it kinda makes you want to gag. You'd be not far wrong if you thought that this town was populated by total flakes!

[RFW]

[The reason we use it in race cars is that pure nitrogen has a coefficient of expansion of 0.8, as opposed to 1.0 for air.

Total baloney! You have clearly forgotten your high school science!

 

ALL the gases that make up air (approximately 78% nitrogen, 21% Oxygen, almost 1% argon, and trace amounts of other gases), ALL obey the standard gas laws that state the volume occupied by a gas at constant pressure is directly proportional to its absolute temperature. Alternatively, the pressure of a gas constrained in a fixed volume (your tire), is directly proprtional to its absolute temperature.

 

This is true for Nitrogen, or Oxygen, or Argon, OR the mixture of all three that make up 99+% of what is called "air".

[ShovelStrokeEd]

Bob, that is totally true, until you get down to cryogenic temperatures, there is then a non-ideality factor which must be taken into account. Nothing much to worry about as very few motorcycles are going to operate with their tires at 77K. Or even have tires at that temperature.

[Ken H.]

I haven't been reading this thread because I figured the subject was covered long ago. But then I decide to 'pop in' to it this morning and true to BMWST form, it's talking about molecular sizes, cryogenic temperatures, and "a non-ideality factor." (Whatever that is.)

 

Gotta' love it!

[tomk99r11]

Sounds like some made up stuff to us normal guys!

[John in VA]

Sounds like some made up stuff to us normal guys!

 

If it is made up stuff, we'd never know anyway!

[RFW]

Bob, that is totally true, until you get down to cryogenic temperatures, there is then a non-ideality factor which must be taken into account. Nothing much to worry about as very few motorcycles are going to operate with their tires at 77K. Or even have tires at that temperature.

Actually, Ed, it strikes me that at 77K, the tires would be so rock-hard, there would be no need for air or pure nitrogen, or whatever.

 

One other thing that occurs to me is that because of the Law of Partial Pressure, even IF you filled a tire with pure nitrogen, it will not stay pure for long. The other constituents of air (mainly oxygen and argon) will diffuse INWARD (AGAINST the high pressure in the tire) and dilute the nitrogen. If left long enough, the precentage of each of the gases in a tire that once contained pure nitrogen, will be exactly the same as that of air.