I would like to discuss Nitrogen in tires for track days

[Philkinson]

Hey guys,
We recently obtained the oh so Holy Nitrogen tank at my work. The rep was telling me all about it, and what caught my attention was when he mentioned that Nitrogen doesn't expand/contract nearly as much as regular air does with change in temperature. Nitrogen molecules are also larger than oxygen, so less likely to get a leak. Whoopdeedo.
Anyways, has anyone run nitrogen on the track, and if so, are there any "noticible" differences? I assume, because the tire temperature won't affect your tire pressure as much, you could run a higher pressure right out of the gate? Do professionals run regular air? So, discuss I suppose, I'm curious.

[OreoGaborio]

The most notable difference is that you'll have to run different (higher) pressures than everyone else, because their tire pressures will rise more than yours. Congrats... You're now a "test pilot".

I see ZERO practical real world benefit (ie, I see the benefits of Nitrogen, but...) I don't know a single person, from street rider to top level expert racer, who bothers going through the trouble to use nitrogen. Why bother? Air is all around us & it's a lot more convenient to pack that into our tires instead.

[Rosco61]

Would you not still have a partial air/nitrogen mix unless you evacuated the tires. Shraeder valves only work one way anyhow. Maybe there is a way to do it ?

[Degsy]

Wirelessly posted

Snake oil. (IMHO)

[Eric Baker]

Nitrogen is just a way for dealers etc. to get more money from customers, snake oil as Degsy said. The only people it "may" benefit is people too lazy or clueless to check their own tire pressures, or get freaked out by their tire light being on, which, unfortunately, are many. It's completely unneccessary.

[joeswamp]

Supposedly it's useful at the absolute highest levels of racing (like F1 and MotoGP) because the supplied nitrogen contains so little moisture. Any moisture in the gas causes expansion as temperature rises, and so running nitrogen in the tires allows for very constant tire pressures as the temps change.

For mortals it makes no difference whatsoever.

[Degsy]

Wirelessly posted

I'd agree with that. Maybe snake oil was a strong phrase. It does have its benefits but they are minuscule to the very highest level if racing and non existent to lowly privateers and trackday junkies.

[Garandman]

Been running a 78% Nitrogen mix for years, myself.

Minimizing the moisture content out of the compressor seems to be more important to minimize changes in pressure.

Clearing the air about Nitrogen.

[Degsy]

Wirelessly posted

Been running a 78% Nitrogen mix for years, myself.

Minimizing the moisture content out of the compressor seems to be more important to minimize changes in pressure.

Clearing the air about Nitrogen.

Haha. I see what you did there.

[golden chicken]

Garandman beat me to it.

[Mr. Kurtz]

Wirelessly posted

I'd agree with that. Maybe snake oil was a strong phrase. It does have its benefits but they are minuscule to the very highest level if racing and non existent to lowly privateers and trackday junkies.

Exactly.

I was approached by a rep for a company selling a nitrogen fill system last year at NHMS during an LRRS weekend. Adding any additional cost for nitrogen fill just isn't worth it for motorcyclists, especially at the track, where you swap tires so often and monitor pressure so closely.

[golden chicken]

You still should check your pressures every month or more. You should obviously adjust them as neccessary. It doesn't matter how big your nitrogen molecules are if you've picked up a nail in your tire or if the rim is corroded where the bead seats.

Many of my customers who get service two or three times per year come in around this time of year with 24-27 psi in their tires or less because they were last checked and adjusted mid-summer. This wears out the tread much faster, dulls steering response, damages sidewalls, and hurts their gas mileage.

It's sad that people would pay for nitrogen fill and then continue to neglect their tire pressures when really all they have to do is take free compressed air and 5 minutes each month to save themselves hundreds of dollars each year in gas and tires.

Even an initial investment in a half-decent portable 12V compressor and tire pressure gauge can be offset quickly by savings in gas mileage or by getting another 10,000 miles out of a set of tires.

[Garandman]

/Many of my customers who get service two or three times per year come in around this time of year with 24-27 psi in their tires or less because they were last checked and adjusted mid-summer. This wears out the tread much faster, dulls steering response, damages sidewalls, and hurts their gas mileage.

It's sad that people would pay for nitrogen fill and then continue to neglect their tire pressures when really all they have to do is take free compressed air and 5 minutes each month to save themselves hundreds of dollars each year in gas and tires./

This is a good point.

I use a bicycle tire pump to adjust pressure - compact, reliable and fairly fast. For fills I have a tank. And as you state, when I checked the tire pressures on the V-Strom last month before a ride, the front and rear were both about 25 psi.

[golden chicken]

Motorcycle tires are especially sensitive because their small volume means it only takes a small amount of air to change pressure levels.

[xsiliconkid]

Anyone running Michelin tires changed by Sto at LRRS is running Nitrogen in their tires.

I think it's a good idea for even club racers to consider nitrogen, if they have easy access.
It is cheap and can be stored in a small gas bottle - lasts quite a while. (Purging the tire a couple of times gets rid of most of the “air”)

The theory is you set your tire pressure cold, to what you previously ran hot - there is definitely less or minimal tire pressure difference due to various tire temps and air humidity. Advantage comes from stable pressure off warmers (or cold) going out on track to when tire temp stabilizers during an on track session (which can be different depending upon track temp.)

Humidity
The biggest culprit comes from a compressed air storage tank, holds variable and large amounts of moisture (water vapor) - this is what expands with temp, the water vapor not the "air" itself.
Using a hand pump can also help keep the moisture content low.

Advantages of Nitrogen
1 It is totally inert - will not react with tire compound
2 Molecules are bigger and less likely to leach through tire carcass
3 no moisture content to cause pressure changes with temp.

If you are worried about ( can feel the effect) of 1-2lbs change in tire pressure - Nitrogen is the way to go.

[golden chicken]

Nitrogen gas WILL change pressure with temperature. The only argument there is that pure dry nitrogen will change pressure at a known, predictable rate, whereas plain, compressed air has more variables.

Don't forget also that the tires are subject to exterior exposure as well. There's plenty of oxygen and moisture outside the tire, even if there isn't any inside. Things like UV rays and oil or coolant on the road also affect the performance and life of the tire.

[xsiliconkid]

Nitrogen gas WILL change pressure with temperature. The only argument there is that pure dry nitrogen will change pressure at a known, predictable rate, whereas plain, compressed air has more variables.

Don't forget also that the tires are subject to exterior exposure as well. There's plenty of oxygen and moisture outside the tire, even if there isn't any inside. Things like UV rays and oil or coolant on the road also affect the performance and life of the tire.

True, N2 does have a linear Thermal expansion coefficient - yes we are talking about :"dry" nitrogen.
From a practical standpoint we are talking about the large tire pressure change we see in tires is related to the moisture H20 content.
Anyone want to do the math on tire volume and pressure change on the above - dry nitrogen vs air with say 50% humidity at 60 degreeF and 170 degree, starting pressure of 30psi

[nt650hawk]

Even if you go to the N2 route there will still be regular air in the tire unless you are changing the tires in a N2 environment. You are still going to get some pressure difference, just not as much.

[G21forme]

And what if you need to add a few psi?

[marshdrummer]

Off topic - gino, that picture is PRICELESS!

[JettaJayGLS]

I can see the benefits.

As a club racer I think that the bit of additional work required (ie: checking pressures right before you go on the track, right when you get off the track, and using practice and other races to hone in the correct "off-the-warmers" pressures for the day) along with high availability and free air, outweighs the marginal increase in performance of using Nitrogen when you combine it with the cost increase and the inconvenience of having to bring your own nitrogen tanks to the track. What happens when you run out of nitrogen and you have no reference for what pressures to run regular air with? As far as I know it is not sold at the track, nor do many people use it to "borrow" some.

For street/track days its not even a question.

[nt650hawk]

Off topic - gino, that picture is PRICELESS!

[a13x]

You only get the most out of nitrogen in your tires if used in conjunction with the brake ram air duct. Buy both and see the laptimes plummet!

[strgt]

Nitrogen is old news, the really fast guys use helium.

[jwm2k3]

I have zero experience with nitrogen in tires and almost zero knowledge about it. My thought was that the nitrogen filled tires 'lost' less pressure than air filled tires due to less permiation of the nitrogen. (In dumbass terms, so I can understand myself, air escapes faster than nitrogen...over time.)

Is this correct?