N2 Nitrogen ?

I am going to inflate my new inner tubes with nitrogen. The manager of a local tire dealer offered to let me use it for free.
Lots of sketchy, incomplete, and speculative information floating around about the stuff. I would like to not have to pump up as often (I'm getting seriously lazy).
I hear bicycle racers use it, and I hope tubes will last longer due to decreased oxidation and consistant pressure. The store manager assured me that it couldn't hurt (I heard a rumor that it would freeze and crack the rubber), so I guess I volunteer to be the guinea pig to test it out commuting. It is generally not considered practical or popular for widespread use currently.
Anyone here who tried it or knows of its effectiveness? The guy at the LBS thinks it's a hoax. :?

airplane tires, racing tires and long-distance truckers benefit a tiny bit from moisture-free nitrogen-filled tires.
Bicyclists, not so much
air is 80% nitrogen, btw

I wouldn't advise paying for it, as long as air is mostly free. They can fill a car tire for a cost of about 25 cents and charge up to 10 dollars a pop to the customer, so it can be a good investment for the store to make a lot of money. Some stores put it in all their tires for free, but are usually hesitant to add it to a bicycle tire.

Nitrogen or air, I wouldn't start a ride in mountain trails without checking tyre pressure anyway. Also, my tyres don't last long enough to think about inflating them with nitrogen. Shocks are another story: Nitrogen filled shock are very stable and don't de-tune with the heat of a hard ride. Once it is set and riding fine, you can seal the can and the shock will last perfectly tuned until the seals are worn out and the next rebuild is due.

I put it in my car tires 2 years ago and set them to 34psi....my dash readout 2 years later is F 34/33 R 33/34

I'm a believer....now if they only made a small system for home use or cartridges.

The biggest advantage N2 has for tires, shocks , etc,..is that by default of its commercial production process.. it is devoid of any water vapor. If you can get 100% dry air it will perform just as well.
All gasses expand and contract with heat, the big issue is when you get water vapor included, then the volume/pressure change is much greater.
Many race teams use N2 also because it is relatively cheap ( in commercial bottles) and quicker, easier, quieter, more compact, etc etc, than lugging a compressor around the pit area.

Installed the N2 today. The first thing I noticed right away is the difference in density. Sixty pounds of nitrogen feels and rolls like eighty pounds of compressed air. The real test for me will be what the pressure is in a week or two. :wink:

Two weeks later and the tires are still hard as a rock.

The fingers said:

Installed the N2 today. The first thing I noticed right away is the difference in density. Sixty pounds of nitrogen feels and rolls like eighty pounds of compressed air. :wink:

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consider carefully what you say..
Its better to remain silent and have others think you may be a fool...than to post something that removes all doubt !

I was inflating to 80psi with compressed air every week. Now the 60psi of N2 pedals just as easily, rides solidly, and the pressure is still the same after two weeks. Let us understand that it really is just a silly little molecule. :lol: I wonder how many TDF teams use it. :wink:

I believe you are experiencing placebo effect. :wink:
80 pounds of lead does weight the same as 80 pounds of feathers, same goes with gas pressure.
The only improvement is stability: N2 will not vary as much with temperature changes and does need a slightly bigger hole to leak.

I might then increase the pressure in 5 lb. increments over time just to see what happens. I wouldn't much recommend it for a "cushy" ride.

Doing a bit more diligence...

Are Nitrogen Molecules Really Larger Than Oxygen Molecules? (pdf)

The short answer has to do with stronger electronegativity rather than molecular weight: Because Oxygen is more reactive than Nitrogen, regardless of the molecules' mass (32 vs 28) - it forms a smaller cloud; it is more compact by 30% and thus is able to pass more easily between larger molecular chains. The link above provides a very good detailed read.

That said, as gasses go:




H | Hydrogen is the most highly reactive and has the highest permeability.
He | Helium is inert, though is 2nd in permeability, and is used to conduct leak tests where Life is critical such as gloveboxes and nuclear reactors.
N | Nitrogen is slightly more towards the center of the Periodic Table of Elements and is less reactive than those closer to the left and right edges.
O | Oxygen, as previously stated is more reactive than Nitrogen and is smaller.
F | Fluorine is the 2nd most reactive element after Hydrogen and smaller than Oxygen. Wicked dangerous stuff, Hydrofluoric acid (HF) is able to melt glass
Ne | Neon - like Helium is a noble gas and non-reactive. It too is smaller than Oxygen, so not a good candidate for tires.
Cl | Chlorine is the next gaseous element, though it's in the same column as Flourine - and really nasty highly reactive stuff that naturally kills life in general.
Ar | Argon, the third noble gas after Helium and Neon, is also the 3rd most abundant gas in Earths' atmosphere making up to about 1%.

If we're worried about leaks and money was no object - I'd use Dry Argon to fill my tubes having about 50% larger diameter than Nitrogen, and being nearly inert. Both Nitrogen and Argon display affinity for water although it does not detract from the sealing abilities. Argon is a thermal inhibitor (used as filler in 2+ paned glass) and can displace air - but it 38% heavier, whereas Nitrogen easily blends with air - but is 3% lighter... and less expensive.

FWIW - I'm cheap and I use one of these at home:



Need only to check pressure during the change of seasons (or significant environmental changes when On The Road).

Rolling along, KF

Remember who is making the money on the process. These guys have a inside saying, it goes something like, "we rent nitrogen". They pay next to nothing for it and charge you for the transport / storage, and you use it and give it right back. They are the ones that have most of the patents on the machines (generators) also.

It is better, no doubt on shocks, air tools and motor racing tires, but bicycle tires I would say would most likely not be noticeable on a performance level. I guess if I were close to the podium at Le Tour, I would not question the mechanic if he wanted to do it. It would be good to compare on the rolling resistance tests on the top road bike tires to see if statistically significant. Maybe one the mythbusters would entertain if the air... company is not a sponsor.

Wow, the gas comparison is very interesting, thanks! Too bad neon doesn't show more promise; with some transparent sidewalls, tubes, and rims and a few spare electrons, the photons generated could make me more visible and thus safer at night. 8) :lol:

The fingers said:

8) :lol:

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:lol:

I believe fingers is now "one with universe". Or at least his tires are.

Nitrogen's performance in a tire is undetectably different from dry air in a tire.


There are many myths about Nitrogen being constant pressure as temperature changes in a tire etc, they are all BS. It behaves identically to dry air.

Likewise, for a bicycle, I don't think wet air would ever matter either, as you're not reaching the tire temps to matter.

Nitrogen's performance in a tire is undetectably different from dry air in a tire.

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I have had this discussion many times in the past. Agree, "DRY" air is key. Hard to get in hot humid conditions. When asking around, I could find Not one of the chiefs of any of the major car racing teams that would go back to air unless they were out of N2. May be mostly hype, but some of them I know were not that gullible. Interesting, how deep it set in those circles. We may be missing some of the key advantages it appears to be showing for them. It may be as simple as sponsorship for the winning teams and everyone else dare not argue with the success.

Those small "whippet" sized canisters of air you can buy at your LBS, are they dry air? And can you get it in nitrogen if you wanted to pursue that avenue? Personally, the only reason I'd go N2 is the feeling I'd get after putting down a Guinness (nitrogen infused). Then I'd feel some weird symbiotic connection to my bike tires. Definitely would change my usual response after a pint of Guinness: that Ireland gets a fair amount of good surf and I need to go there before I grow old and afraid of cold water.

My two variable experience, heavy Michlen tires and Nitrogen from Costco, on a Toyota Tacoma Prerunner is at 35 PSI the stuff doesn't leak out between 3000 to 8000 tire rotations. I can also drive around with screws in the tires without repairing them. I live in Dallas, Texas U.S.A, so gas station air may be prone to moisture. I respect the science presented on this thread. It sounds like the Michlens may be due the majority of the credit. Having said that, I'm sold on Michlen and Nitrogen, and Costco tire service for that matter. For my bike, I'm content to add air with my hand pump every few weeks. The Hookworms I run have been totally resistent to flats.

Those small "whippet" sized canisters of air you can buy at your LBS, are they dry air?

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I think they are CO2. Carbon dioxide. Nitrous would have a whole new following. :lol:

Two months have gone by and the tires are still hard as a rock. I'm going to install it in my other bikes too.