Nitrogen in place of air in tires

No gimmick. The Nitrogen they are talking about is the same grade and quality as they use here in the aviation community. It's dry and pure, something that regular air that a normal compressor pumps is 100% opposite. In the aviation community we spend tremendous amounts of time and money to ensure that our tires are filled with 100% dry nitrogen, and that our wheels are not corroding internally or externally for that matter. I have yet to see an Aircraft wheel corrode internally, but next time you have the tires on your car or bike changed ask to see the wheel- I bet what you see will surprise you. Do you see a HEPA filter and water seperator on the compressor where you air your tires? Time, pressure and temperature are all acting on your tire and your wheels when using regular air. 100% Nitrogen takes alot of that out of the equation, resulting in a healthier tire and wheel. The science of it all is undeniable.

oh and Mythbusters killed the whole using a tire for air source under water.....

 

My point exactly (oxygen & other air gases are corrosive to rubber), I sub-mentioned the eternal tyre care, but didn't stress that, so thank you for further pointing that out.

comes down to, do you think your bike & life is worth $2.00 more ( less if you buy a tank) a tyre to improve safety & reduce wear :crutch:

No brainer in my book (that's the common sense of smarts book) :biggrin:

 

Although a noble effort, your trucking test is rather meaningless from a scientific testing approach. Disclaimer: I'm not a scientist but I did sleep at a holiday in last night. But I know you'd need a large sample of trucks simultaneously driving identical routes with identical payloads on identical tires and ideally even the drivers wouldn't know what gas their tires contain.

What does the 5-10k miles figure mean as a percentage? I don't know what mileage a trucker tire gets but I'd bet the rear trailer tires are the lowest of the 18.

I do understand the principles of inert gases and certainly don't dispute their physical properties.

What I really want to know is how much more mileage am I going to get out of a rear tire if I go to all the effort and additional expense? 5%, 10%, more? The safety claims are a meaningless issue to me as a deer or the cell-phone SUV are MUCH bigger real world threats to my life than if I'm running 79% or 90% N2 in my tires.

 

GoinPhaster,
I missed that episode of mythbusters. I was kidding of course though

 

moot, not mood...sorry:redface:

 

fotomoto
FWIW and FYI
Nitrogen is not an inert gas. if you don't believe me, light up some dynamite(TNT-trinitrotoluene) that will mike it clear for you. or take a whiff of CN (cyanide)
I love organic chemistry. It amino world without chemisrty
Inert gases are: Helium, Neon, Argon, Krypton, and Radon there is a new one but i don't know its name atomic number is 118

 

i've never heard love and organic chemistry in the same sentence. i barely made it thru.:loco:

 

Ununoctium, yes I'm a dork.

 

Man, what a thread! Let's start a "what kind of oil" thread next.:biggrin:

 

Yes you are indeed correct. Twenty-five years ago, I was glad the prof mercifully gave me a D in organic chemistry.:frown:

But here's wiki's definition of Nitrogen and what my one brain cell was referring to:

"Nitrogen (pronounced /ˈnaɪtrədʒən/) is a chemical element which has the symbol N and atomic number 7. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78.1% by volume of Earth's atmosphere. Nitrogen is a constituent element of all living tissues and amino acids. Many industrially important compounds, such as ammonia, nitric acid, and cyanides, contain nitrogen."

 

Let's expand upon this statement. purely neutral here so bare with me.:yield:

If you have a motorcycle and you ride it as much as we as a group do (something to do with a great all around bike......) would stability be a bad thing? isn't that one of the reasons you bought a VFR? such a stable bike in varying conditions? How about knowing what your pressures are regardless if you drove 0 miles or 250? Hot or cold tires? Changing seasons but not pressures? What about knowing EXACTLY what PSI the bike responds best to? How many benefits are there to 100% nitrogen?

Now ask yourself this question-
If 100% nitrogen was as readily available as the air found at a gas station would you still use the air? No one has yet to give the same reasons as to why air from a compressor is better than 100% nitrogen save one- it's readily available.

The arguement that it only has benefits for race applications is- well, flacid. How many past "race only" technologies are now standard equipment on today's motorcycles, let alone all forms of transportation? Where would we be if we didn't move forward?

Say 100% Nitrogen not practical(easy)? Absolutely. Say there are real world benefits to 100% Nitrogen? Absolutely. After that it comes down to one pure dynamic. Choice.

 

The name of the game is optimal tire profile and maximum traction at all times and both of these depend on keeping a constant tire pressure. Secondary considerations for modifying gas composition in a tire might include 1) leak rate of gas from the tire due to diffusion through the rubber and microscopic leaks in the rubber-to-metal seal (bead), 2) corrosion of the wheel due to moisture in the tire, 3) rate of pressure change with time and possibly 4) combustion due to Oxygen.

Dry air consists of 78% Nitrogen, 21% Oxygen, 0.9% Argon and 0.03% Carbon dioxide by volume. Atmospheric water can vary from 0 to ~4%. Nitrogen, Oxygen, Argon and Carbon dioxide all obey the ideal gas law (PV=nRT) at reasonable temperatures and pressures (i.e., those that are found in tires). The ideal gas law relates tire pressure to temperature (Kelvin scale) and hence a doubling of temperature will result in twice the pressure. Water vapor deviates only slightly from the ideal gas law and will not behave much differently than Nitrogen. Water does condense as well as freeze and this could make a small difference, but we are talking minimal noticeable results since it is unlikely that the gas in a tire will remain below freezing during driving. Although, if a tire were filled in sub-freezing weather than this may make a difference. Still , we are talking at most a 4% difference.

Another consideration to minimizing change in tire pressure with temperature is the heat capacity of a gas. The heat capacity is a measure of how much heat is required to raise the temperature of a gas. For example, it takes 1 Calorie to raise the temperature of 1 gram of liquid water 1 C. So, a larger heat capacity will take more heat to raise the equivalent amount of a lower heat capacity gas the same temperature. In the end, a lager heat capacity will translate to a more gradual increase in tire pressure with time. Heat capacities (Cv) are: Water (1.81 kJ/kg K), Nitrogen (0.74), CO2 (0.66), Oxygen (0.65) and Argon (0.31). Since water has the highest heat capacity it is better in this respect, while Nitrogen is next. In the end, heat capacity will only effect the rate at which a tire heats up and not the end temperature.

Diffusion is a function of molecular weight (amu = atomic mass unit) and to some extent the size of the molecule: Carbon dioxide (44 amu), Argon (40 amu), Oxygen (32 amu), Nitrogen (28 amu), and water (18 amu). Since water is the lightest it will diffuse quickest, but following this reasoning one would want to fill the tire with Carbon dioxide or Argon instead of Nitrogen. Since CO2 deviates from the ideal gas law it is a poorer choice and Argon would be better, but quite expensive.

In the end, the benefits of pure Nitrogen are 1) does not condense in extremely cold weather, 2) diffuses less than water, 3) will not corrode wheels and 4) will not burn. The fact that Nitrogen does not corrode or support combustion is the reason that pure Nitrogen is probably used in aircraft tires. The reason NASCAR uses Nitrogen is probably because they are driving at the extreme limits of traction and even a 1-2% change in tire pressure will make a difference. With regards to street use I doubt it makes much difference since other factors that effect traction such as road surface irregularities (sand, oil, tar and water) will far outweigh the small differences that a few percent change in tire pressure would. But hey, if it makes you feel good then fill those tires with Nitrogen.

 

SWS,

Man, that was beautiful, couldn't have said it any better myself. That's why I love this site. and I say unto you all " if you want to fill your tires with gas from an outhouse and it makes you feel better then go for it."
Joke
Q: Do you know how to spot a happy motorcyclist?
A: count the bugs on his teeth

 

Guys,

All gases respond to temperature changes the same as defined by the ideal gas law: pv=nRT

And just remember, air is 78% nitgrogen to begin with.

 

My personal air compressor does indeed have a water trap, but I'm still looking into the inline HEPA filter

 

Nitrogen is not an inert gas in the sense that argon is, but it behaves very much like being an inert gas, that is, there is no oxidation in the presence of 100% nitrogen. This is NOT the same as nitrogenous compounds, eg. cyanide, or explosive, e.g. nitroglycerin being inert.

 

Aircraft use nitrogen in their tires to help limit the amount of hot brake blow outs. Aircraft still can suffer blow outs with nitrogen serviced tires.

There is some truth that servicing your vehicle tires with nitorgen can help calm tire pressure buildup, but it is hardly noticable. For everyday use, it would be just a waste of money. You will be required to service tires just as often with 100% nitrogen as you would with regular dry air.

Get a accurate tire gauge and check your tire pressure more often. Doing this will ensure proper tire wear and higher longivty for your tires. Nothing wrong servicing tires with nitorgen, it is just that not everyplace you goto has nitrogen available and it costs more.

 

I used to work at a bike (pedal bike) shop. Sometimes when working on buddies bikes, I would use a floor pump and through an elaborate process of dissasembling it and filling it with water and pumping that water into their tubes in the tires, I could half fill the tire with water. Then top it off with air.

Let me tell you, it is a riot when you get to the trail head and their bike weighs 5 lbs more, and they cant put their finger on it but it isnt riding right. Then you suggest letting some air out of the tire, and if the nipple is on the bottom they get hosed down.

If someone did this to my motorcycle somehow, id kill em.

Anyone see those airless tires that were in popular science a while back? You can see right through them and they just sit on the rim and have some flexible support structure between the rubber tread and the rim bead. It is something sweet and I want em on my moto-bike! I wonder how they handle lateral forces though...