Nitrogen in tires

[viney266]

We were talking about this in another thread.

Like most things on the web ( seafoam being my favorite) it has been given almost magical properties. It cleans your clothes, takes care of business, cures disease etc. What does it REALLY do?

My info? I have seen a few articles on it some pro some con.

I do know we were running it in race tires on motorcycles at Daytona way back in the 80's for stability and more consistent temperatures.

One of the members here has seen positive results as well.

Lets discuss here and not muddy up another thread

[Syd]

You're nearly 80% there now. That additional 20% (and you can never get a full 100% under normal conditions) costs a lot for very little effect on the scoot.

That's my opinion.

[charlie55]

You're nearly 80% there now. That additional 20% (and you can never get a full 100% under normal conditions) costs a lot for very little effect on the scoot.

That's my opinion.

Syd, I think he meant the 1980's, as opposed to running 80% pure nitrogen.

[Lokky]

You're nearly 80% there now. That additional 20% (and you can never get a full 100% under normal conditions) costs a lot for very little effect on the scoot.

That's my opinion.

Syd, I think he meant the 1980's, as opposed to running 80% pure nitrogen.

Lmao, air is just below 80% nitrogen, that's what he's talking about

Disclaimer: The following experience was the result of using inner tubes that were drained of all air before inflating with nitrogen and purging three times. The nitrogen used was 99.9999% pure coming from a tank, not the 95% pure stuff you get from a machine.

I ran nitrogen in my tires on the way to Amerivespa (900 miles with a mountaneering backpack full of camping gear + saddlebags) and my tires looked almost like new when I got there (Stock maxxis tires that came with the 2T, they had 50 miles on them at the beginning of this trip).

At amerivespa I had to replace my exhaust and to get to the big nut they deflated my rear tire, then reinflated it with air. After the first leg of the trip back (450 miles in one day, WOT) the tire was showing significant wear and was getting squared off.


I do believe that the tire runs colder when filled with nitrogen because of the displacement of moisture. Water has a specific heat capacity that is four times that of nitrogen. In layman terms this means that it takes more energy to heat water up, but once it is heated it is harder to cool it down. Energy is constantly supplied to the system in the form of heat due to friction between tire and road, but nitrogen can shed this energy more readily due to its lower heat capacity, whereas water would retain it and cause the tire to run hotter. (I am a chemist btw, physical chemistry is not my field but this model should make sense)


Here are a couple pictures of the tire in question by the way, http://imgur.com/ND2k1W0 you can see how abruptly the curvature changes on the side by how the light is cast, here is another shot http://imgur.com/ofJk4p8


On top of me, two of the people that rode the cannonball last year filled their tires from that same tank of nitrogen and their tires lasted from coast to coast without needing to be changed, whereas other riders were changing their tires every 2-3 days.

[charlie55]

Oh, I see. I was thinking in terms of NJ air, which is 80% methane.

[Syd]

two of the people that rode the cannonball last year filled their tires from that same tank of nitrogen and their tires lasted from coast to coast without needing to be changed, whereas other riders were changing their tires every 2-3 days.

This is interesting, Lokky. Which scoots (models)?

[magnato1]

You're nearly 80% there now. That additional 20% (and you can never get a full 100% under normal conditions) costs a lot for very little effect on the scoot.

That's my opinion.

Syd, I think he meant the 1980's, as opposed to running 80% pure nitrogen.

Lmao, air is just below 80% nitrogen, that's what he's talking about

Disclaimer: The following experience was the result of using inner tubes that were drained of all air before inflating with nitrogen and purging three times. The nitrogen used was 99.9999% pure coming from a tank, not the 95% pure stuff you get from a machine.

I ran nitrogen in my tires on the way to Amerivespa (900 miles with a mountaneering backpack full of camping gear + saddlebags) and my tires looked almost like new when I got there (Stock maxxis tires that came with the 2T, they had 50 miles on them at the beginning of this trip).

At amerivespa I had to replace my exhaust and to get to the big nut they deflated my rear tire, then reinflated it with air. After the first leg of the trip back (450 miles in one day, WOT) the tire was showing significant wear and was getting squared off.


I do believe that the tire runs colder when filled with nitrogen because of the displacement of moisture. Water has a specific heat capacity that is four times that of nitrogen. In layman terms this means that it takes more energy to heat water up, but once it is heated it is harder to cool it down. Energy is constantly supplied to the system in the form of heat due to friction between tire and road, but nitrogen can shed this energy more readily due to its lower heat capacity, whereas water would retain it and cause the tire to run hotter. (I am a chemist btw, physical chemistry is not my field but this model should make sense)


Here are a couple pictures of the tire in question by the way, http://imgur.com/ND2k1W0 you can see how abruptly the curvature changes on the side by how the light is cast, here is another shot http://imgur.com/ofJk4p8


On top of me, two of the people that rode the cannonball last year filled their tires from that same tank of nitrogen and their tires lasted from coast to coast without needing to be changed, whereas other riders were changing their tires every 2-3 days.

This is interesting. There is a lot of reference to heat here, but I am confused. As the tire gets warmer, the air particles within should get hotter and move at greater speed and thus the tire pressure should increase, right? So why, at speed, when the tire is hot, would it square off? Isn't squaring off an indication that it was running a little low?

[Lokky]

Syd, there were actually three scoots now that I think about it, a buddy 125 (scootbootfirefighter's) a GTS and a P200.

Magnato, temperature changes actually only have a limited influence onture pressure. The ideal gas formula states that PV=nRT.
According to this doubling the temperature would double the pressure (at constant volume).
The trick is that for this formula to work you must use temperature in kelvin, not Celsius. Room temperature in kelvin is 298 K. Let's make up a number and any that the tire is running at 60 degree Celsius, that's 333 Kelvin. Going from 298 to 333 is about a 10% increase, so not very dramatic.

The tire I posted was kept at 34psi cold to compensate for the weight of my camping gear and saddlebags. No chances of it being under inflated.

The issue with scooter tires is that they are so small, thus they must rotate much faster than a motorcycle tire to reach the same speed, thus leading to higher temperatures. High temperatureres make thetire compound softer and cause it to water faster. Add to that that most 10" tires are not exactly designed to ride over 50mph all day long and you have a tire that will square off like that. Nitrogen went along way in preventing that.

[Rob]

This reminded me of a similar discussion in a previous thread:
viewtopic.php?t=9742&highlight=

For the record, I don't believe there are any significant short term benefits from running N2 in your tires. Certainly nothing that can be cost justified ... assuming you're paying higher prices for the product.

Rob

[PeteH]

So is the _real_ issue the use of nitrogen itself, or is it in fact about running with a 'drier' gas in the tire to avoid water heating? Would air that's still in normal atmospheric proportions but run through an air dryer be as effective as the shop-grade or lab-grade nitrogen? What about another inert gas like CO2?

[still shifting]

A very interesting thread. I am always fascinated by other peoples expertise. How long will this gas stay in a non leaking tire? R

[magnato1]

Syd, there were actually three scoots now that I think about it, a buddy 125 (scootbootfirefighter's) a GTS and a P200.

Magnato, temperature changes actually only have a limited influence onture pressure. The ideal gas formula states that PV=nRT.
According to this doubling the temperature would double the pressure (at constant volume).
The trick is that for this formula to work you must use temperature in kelvin, not Celsius. Room temperature in kelvin is 298 K. Let's make up a number and any that the tire is running at 60 degree Celsius, that's 333 Kelvin. Going from 298 to 333 is about a 10% increase, so not very dramatic.

The tire I posted was kept at 34psi cold to compensate for the weight of my camping gear and saddlebags. No chances of it being under inflated.

The issue with scooter tires is that they are so small, thus they must rotate much faster than a motorcycle tire to reach the same speed, thus leading to higher temperatures. High temperatureres make thetire compound softer and cause it to water faster. Add to that that most 10" tires are not exactly designed to ride over 50mph all day long and you have a tire that will square off like that. Nitrogen went along way in preventing that.

Thanks for the explanation. So it's not about pressure, but temperature of the rubber itself. So, arguably, buying a nicer tire, like a Heidenau, would probably be easier for most folks than putting 99.9% nitrogen into the tire. Do you think that having a better tire will have a greater effect on the wear than the nitrogen?

[Syd]

^^ Better for what?, is the question. Most 'better' tires are better for cornering than mileage. For example, the Duro's that came on my SYM were so hard that barely aggressive turning was a challenge, but they lasted for over 10,000 miles. I got barely 6,000 out of the replacements (don't remember the brand), but they gripped like super glue.

[brianwheelies]

What makes little sense to me is the "ratio" of atmospheric air going into the tire is 80%, why after the air seeps out and is refilled with atmospheric air, is the tire not eventually working its way to 100% nitrogen?

Is it because our air is the compound that does not separate into individual components?

[Lokky]

Thanks for the explanation. So it's not about pressure, but temperature of the rubber itself. So, arguably, buying a nicer tire, like a Heidenau, would probably be easier for most folks than putting 99.9% nitrogen into the tire. Do you think that having a better tire will have a greater effect on the wear than the nitrogen?

I feel like it would depend on the kind of riding you do. A heidenau will definitely last longer (assuming you don't get a super soft one, my k58 lasted 3k in the rear but I rode it we'll after winter was over). High speed riding for extended periods of time is where the nitrogen will shine.

The ideal combination of course would be heidenaus with nitrogen. Next time I take a trip like that I am taking my k61s and using nitrogen with them, I only used the maxxis to go toaAmerivespa because that's what was mounted on the bike when I bought it the day before.

[Lokky]

What makes little sense to me is the "ratio" of atmospheric air going into the tire is 80%, why after the air seeps out and is refilled with atmospheric air, is the tire not eventually working its way to 100% nitrogen?

Is it because our air is the compound that does not separate into individual components?

I am not sure I understand your question. Air is 80% nitrogen, so by filling a tire with it you will never go above 80% nitrogen content.

[Syd]

What makes little sense to me is the "ratio" of atmospheric air going into the tire is 80%, why after the air seeps out and is refilled with atmospheric air, is the tire not eventually working its way to 100% nitrogen?

Is it because our air is the compound that does not separate into individual components?

I am not sure I understand your question. Air is 80% nitrogen, so by filling a tire with it you will never go above 80% nitrogen content.

Wow, what an idea, brianwheelies.

I think, what he means, Lokky, is that one of the reasons nitrogen is used is that nitrogen molecules are larger than the pores in the tire. This means what escapes from the air-filled tire are oxygen molecules. This would leave a higher concentration of nitrogen in that tire. So when the tire is refilled with air, the concentration of nitrogen in the tire would be slightly higher than the atmospheric 78%, due to the nitrogen left after the oxygen escaped, making the tire low.

Rinse, repeat and you would continually increase the percentage of nitrogen in the tire, eventually approaching 100%.

[charlie55]

So, I guess one could make the case that the filtering action of our tires helps increase the concentration of atmospheric oxygen, thus counteracting the effects of the engine's emissions.

I'm gonna try that one down at the MVC next time they try to nail me for a check engine light.

[Syd]

Especially helpful for two strokes!

[Lokky]

What makes little sense to me is the "ratio" of atmospheric air going into the tire is 80%, why after the air seeps out and is refilled with atmospheric air, is the tire not eventually working its way to 100% nitrogen?

Is it because our air is the compound that does not separate into individual components?

I am not sure I understand your question. Air is 80% nitrogen, so by filling a tire with it you will never go above 80% nitrogen content.

Wow, what an idea, brianwheelies.

I think, what he means, Lokky, is that one of the reasons nitrogen is used is that nitrogen molecules are larger than the pores in the tire. This means what escapes from the air-filled tire are oxygen molecules. This would leave a higher concentration of nitrogen in that tire. So when the tire is refilled with air, the concentration of nitrogen in the tire would be slightly higher than the atmospheric 78%, due to the nitrogen left after the oxygen escaped, making the tire low.

Rinse, repeat and you would continually increase the percentage of nitrogen in the tire, eventually approaching 100%.

hahaha that has my poor chemist brain hurting.

[jdanderson1449]

From my experience in the automotive world, the main reason for using nitrogen in at least that application, is that the nitrogen molecule is larger than the atmospheric "air" the comes from an air compressor. Rubber is a porous material that will, over time, allow air to escape. Nitrogen, being a larger molecule escapes from tires and tubes less rapidly. Motorcycle and scooter tires "square" off from not taking turns. I live in Nebraska, we don't have curvy roads. Every tire that comes in to my shop is square. Ride more curves and your tires will wear evenly. Or buy dual compound tires. Hard center, sticky edges, perfect tire for cornering and long wear. I realize that they aren't widely available for scooters yet but they're on their way.

[ScootLemont]

When Road & Track tackled this subject for regular road driving, they didnt see much reason for it but did concede that when you buy nitrogen for your tires, it most likely will contain little to no moisture. Moisture in your tries has ill effects & since most people fill up with air from a compressor at a gas station or a compressor in their own garage, they usually are pumping a measurable amount of water (moisture) into their tires & thats bad.

[viney266]

I wasn't too keen on using Nirogen until I saw what Lokky had to say about the CBR tires. That made me want to look into it furthur.

When we raced at Daytona the tire manufactorers were using it due to the tire staying more stable with air pressure due to the lack of H2O in the tires. These are tires that their life was measured in Minutes. The top teams would run 4 tires in a 200 Mile race, and apparently they saw a major increase in tread life and lower tire surface temps with the nitrogen. It wasn't huge, but it was enough. As I said, this was being done there in the 80's long before it became a thing for "street" sales.

I agree that a 10" tire running all day at speed is really going to heat up...

[BootScootin'FireFighter]

On top of me, two of the people that rode the cannonball last year filled their tires from that same tank of nitrogen and their tires lasted from coast to coast without needing to be changed, whereas other riders were changing their tires every 2-3 days.

This is good scoop. I had my air swapped out for nitrogen before the start and on fresh tires. They could've held up all the way, but I wanted to play it safe for the last day, so I went ahead with swapping out my rear tire (without a bead breaker, which was an adventure in itself!). I didn't want to risk it on the first two legs of California. First being the most desolate stretch of highway I've ever seen (CA 62 from Parker AZ to 29 Palms), second stretch of national park, desert, and steep curving mountain roads. The same nitrogen tank was in the team Scoot Richmond support vehicle, so I went with it again. This held up to over 2200 miles of all day WOT through some hot roads and varying altitudes. If I had regular access to that quality of nitrogen, I'd use it every chance I can.