Nitrogen filled M/C tyres?

[Duc]

Anyone using Nitrogen in their mc tyres?

Good idea / Bad idea?

I had my car tyres done and thats great but just wonder if "cooler" mc tyres are good thing. Not having to worry about the pressure so often (ie.constant pressure) would be an advantage though.

[vifferman]

Use the 'Search' function, Sir! This topic's been done to death a time or two before.
Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.

[driftn]

Use the 'Search' function, Sir! This topic's been done to death a time or two before.
Nitrogen filled tyres are bollocks


If that is the case why do they us it in F1 and have been for over 50 years.

Nitrogen is good for keeping tyre pressures more stable in between hot and cold tempratures as it has no moisture in it.

Good in cars not so much in bikes as it takes longer for the tyres to warm up to optimum temps.

Also holds pressure longer, had a customer with a Toyota landcruiser came in to my shop in feb last year sold him nitrogen. He came back in 6 months and it hadnt droped a pound came back in november same thing 40psi 10 months with out needing a top up is bloody good going.

[AllanB]

Air is still free and its good stuff - the other is a bit of a marketing wank to get more money out of lazy buggers who never check their car tyres.

Plus on a bike tyre you would still want to check it often to ensure it is indeed holding pressure - thus each time you check it you lose a wee bit of pressure - given a month of checking the tyres weekly you'll need to add some air

[vifferman]

Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.

[Finn]

Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.

Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.

[Sully60]

Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.

Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.





Let's see how long we can keep this going

[UberRhys]

Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.


Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.


Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.





Let's see how long we can keep this going

Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.

[Devil]

You guys can stick your head in the sand if you like. But nitrogen has had proven benefits, more specifically on commercial, high mileage vehicles. Wouldn't bother with it on the bike.

[vindy500]

Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.

[nudemetalz]

Nighty filled tyres are testicles, except that the fanny might be drier, so less prone to erection and contraction. Knob is 80% blood anyway.
Try googling "pornos" and see some of her attributes.

[Mikkel]

Repost!!!!

[Starky307]

Can we design a wave for people who have Nitrogen in their tyres?:jerry:

[Forest]

If that is the case why do they us it in F1 and have been for over 50 years.

Because F1 racing is a fantastically expensive sport in which reliability and fractionally faster lap times are of critical importance.



Also holds pressure longer

No it doesn't.

Atmospheric air is around 80% Nitrogen. Think about it.

[Kickaha]

No it doesn't.



Yes it does

[Mikkel]

Yes it does

Does not...

[noobi]

Does not...

It does so...

[98tls]

Yes it does Thought you might show up here mate.;)

[nudemetalz]

Well does it or doesn't it?
That is the question.
Just like E=MC2

[3umph]

dam kids these days:whocares:

[SARGE]

meh..i run it in the Ace

too early to tell...

[Max Preload]

Nitrogen is good for keeping tyre pressures more stable in between hot and cold tempratures as it has no moisture in it.

Air can have no moisture too - it's called dry air. In operation in extreme temperature ranges like aircraft when they can go from 40 to -60 it might make a difference, but it's used in aircraft because it's inert too.


If that is the case why do they us it in F1 and have been for over 50 years.

See above - extreme service.


Good in cars not so much in bikes as it takes longer for the tyres to warm up to optimum temps.

Bullshit. The relative rates of expansion of air as a mixture of 76% nitrogen and near pure nitrogen as a molecule is so minute as to be statistically insignificant.


Also holds pressure longer, had a customer with a Toyota landcruiser came in to my shop in feb last year sold him nitrogen. He came back in 6 months and it hadnt droped a pound came back in november same thing 40psi 10 months with out needing a top up is bloody good going.

Air does that in my car tyres. But then, air is 76% nitrogen anyway.

How do you ensure that the tyre is completely nitrogen filled, as when it's fitted to the rim it is initially filled with air. How do you ensure you've purged all that when there's only one fill point?


Can we design a wave for people who have Nitrogen in their tyres?:jerry:

There's already one. It goes like this... :tugger:

[Forest]

Yes it does

Tyres are impermeable. There is zero diffusion through the rubber.

The only way that the gas inside a tyre can escape is either:

a. Through the valve (or stem).
b. Through the bead.

Using Nitrogen to fill your tyres has no effect on either of these.

Think about it.

[Kickaha]

Tyres are impermeable. There is zero diffusion through the rubber.

Not according to the guys that build them

[SixPackBack]

Tyres are impermeable. There is zero diffusion through the rubber.

The only way that the gas inside a tyre can escape is either:

a. Through the valve (or stem).
b. Through the bead.

Using Nitrogen to fill your tyres has no effect on either of these.

Think about it.

Fill a tyre with Helium and see how impermeable rubber is......only have to look at Helium filled balloons to see how well it contains light gas [yes some helium will leek out of the seal, but if you did a back-to-back test with air filled balloons the result speaks for itself.............rubber is permeable [but contains Nitrogen pretty well]].

[icekiwi]

Don't forget pressure bleeding through the rim,I worked in the Ford Alloy wheel plant for a fair few years and am responcible for a few falcon tyres going flat...:2thumbsup

[Devil]

Perhaps the backyard scientists among us could actually go look up the facts directly related to nitrogen use, from reputable sources, instead of pretending they know everything, or quoting other backyard scientists.

It's been proven, it works. I dont know why this discussion has come up again.

[Max Preload]

Perhaps the backyard scientists among us could actually go look up the facts directly related to nitrogen use, from reputable sources, instead of pretending they know everything, or quoting other backyard scientists.

Anyone in particular you're like to attempt to refute or would you prefer not to specify names or particular claims?


I dont know why this discussion has come up again.

It's amusing to poke fun at people who swallow every bit of marketing hype and jargon as if it's the word of God himself...

[Devil]

Anyone in particular you're like to attempt to refute or would you prefer not to specify names or particular claims?
Any of the "non-believers".


It's amusing to poke fun at people who swallow every bit of marketing hype and jargon as if it's the word of God himself...
Pull your head in you arrogant prick.

I think the F1 case is a pretty damn good example. Doesn't that ring any alarm bells in your head that maybe, just maybe they're right? y'know, I mean it's not like they spend any money on research and development or anything...

[ManDownUnder]

*yawn*... read this (http://articles.directorym.net/Nitrogen_Inflation_101-a878769.html)
and this (http://findarticles.com/p/articles/mi_m0EIN/is_2008_Feb_27/ai_n24327013?tag=content;col1)

...of note to me...
Due to nitrogen's larger molecular size, it migrates through a tire three to four times slower than oxygen. Whether a truck tire is parked on a trailer or running down the road, if it's filled with "plain old air" it will lose approximately 1.4 to 1.7 psi every week.

According to a 2007 Clemson University study, nitrogen reduces this loss by 69 percent or greater.

They're talking about truck tires. A shit load thicker/stronger and I would expect harder for gases to escape from. As sixpack alluded to - fill the bastards with Helium and watch the fun.

NEXT!

[ManDownUnder]

Tyres are impermeable. There is zero diffusion through the rubber.

The only way that the gas inside a tyre can escape is either:

a. Through the valve (or stem).
b. Through the bead.

Using Nitrogen to fill your tyres has no effect on either of these.

Think about it.

I did - and combined with the results of the Clemson Uni Study quoted above I'd say you're right - it could leak through the bead or the valve - and it would probably happen about 70% faster with air than Nitrogen.

Thanks for the invitation to think about it... turns out you're wrong on a number of counts. C'est la vie.

Open invite to find a reputable source that says I'm wrong. Prefer peer reviewed/scientific type resources if that's ok. KBers are prone to saying things without actually thinking... or knowing. What're the chances?

[Squid69]

*yawn*... read this (http://articles.directorym.net/Nitrogen_Inflation_101-a878769.html)
and this (http://findarticles.com/p/articles/mi_m0EIN/is_2008_Feb_27/ai_n24327013?tag=content;col1)

...of note to me...
Due to nitrogen's larger molecular size, it migrates through a tire three to four times slower than oxygen. Whether a truck tire is parked on a trailer or running down the road, if it's filled with "plain old air" it will lose approximately 1.4 to 1.7 psi every week.

According to a 2007 Clemson University study, nitrogen reduces this loss by 69 percent or greater.

They're talking about truck tires. A shit load thicker/stronger and I would expect harder for gases to escape from. As sixpack alluded to - fill the bastards with Helium and watch the fun.

NEXT!

They also have shitloads more surface area than bike tyres... I would assume that gaps between the rubber molecules are still the same size, no matter what hardness the tread compound is.
You will probably also find that aside from having more rubber, and compeltely different reinforcing, truck tyres and motorcycle tyres are not that much different in construction

I was under the impression that nitrogen was used because when it heats up it does not expand as much, therefore making it easier to keep the tyres at a constant pressure...

[ManDownUnder]

They also have shitloads more surface area than bike tyres...

I was under the impression that nitrogen was used because when it heats up it does not expand as much, therefore making it easier to keep the tyres at a constant pressure...

Quite right but volume of a tyre increases at the same rate as surface area so that can be discounted.

[UberRhys]

I was under the impression that nitrogen was used because when it heats up it does not expand as much, therefore making it easier to keep the tyres at a constant pressure...

Dry nitrogen is just that - dry nitrogen, ie: Nitrogen with no moisture in it.

Compressed air from an air compressor like that in workshops or at service stations is air made up of (mainly) Nitrogen (78.084%), Oxygen (20.947%), Argon (0.934%), Carbon Dioxide (0.033%) which makes up 99.998%. The balance is made up of other traces (Neon, Helium, Krypton, Sulfur dioxide, Methane, Hydrogen, Nitrous Oxide, Xenon, Ozone, Nitrogen dioxide, Iodine, Carbon monoxide, Ammonia).

In addition to the mixture that is air, moisture gets worked into the mix, espically when compressed - and this is what causes the fluctuations in pressure. As the tyres warm up, the moisture content heats up and expands causing the fluctuations in tyre pressure. no matter how good of an inline drier you have on the compressor, moisture always manages to find it's way there.

[roogazza]

Perhaps the backyard scientists among us could actually go look up the facts directly related to nitrogen use, from reputable sources, instead of pretending they know everything, or quoting other backyard scientists.

It's been proven, it works. I dont know why this discussion has come up again.

I've used it when running a Z1 in Six Hour races. The idea was to keep the tyres cooler, whether it worked , don't know for sure ?
I believe the powers that be banned using it after a two years.

But if the modern generation says hoggwash ? LOL Gaz.

[Renegade]

Dry nitrogen is just that - dry nitrogen, ie: Nitrogen with no moisture in it.

Compressed air from an air compressor like that in workshops or at service stations is air made up of (mainly) Nitrogen (78.084%), Oxygen (20.947%), Argon (0.934%), Carbon Dioxide (0.033%) which makes up 99.998%. The balance is made up of other traces (Neon, Helium, Krypton, Sulfur dioxide, Methane, Hydrogen, Nitrous Oxide, Xenon, Ozone, Nitrogen dioxide, Iodine, Carbon monoxide, Ammonia).

In addition to the mixture that is air, moisture gets worked into the mix, espically when compressed - and this is what causes the fluctuations in pressure. As the tyres warm up, the moisture content heats up and expands causing the fluctuations in tyre pressure. no matter how good of an inline drier you have on the compressor, moisture always manages to find it's way there.

everyone go down to their local powder coaters, the inline compressed air dryers are top notch, basically cant have moisture in the lines if your blowing fine powder, fill ya tyres up there for free.

[vgcspares]

hmmmm - Helium you say ?

Wouldn't that reduce the sprung (as opposed to the unsprung) mass - which would give improved suspension at the cost of needing daily top-ups due to the smaller molecules escaping faster ..... or would you need to fit truck tires ?

[ManDownUnder]

hmmmm - Helium you say ?

Wouldn't that reduce the sprung (as opposed to the unsprung) mass - which would give improved suspension at the cost of needing daily top-ups due to the smaller molecules escaping faster ..... or would you need to fit truck tires ?

LOL that's be quite an expense mate... for fuck all weight saving

[elevenhundred]

There seems to be a lot of armchair scientists in this thread.
In reality most of them's experience with gas is with the stuff that comes out their bum, and that stuff is by no means noble or inert :)

[3umph]

the big question is... for Joe public like me is there any advantage/dis advantage to using the nitrogen or world we not notice any difference??

my guess is that no difference would be noted by joe public

[Mikkel]

It does so...

Does not...


Fill a tyre with Helium and see how impermeable rubber is......only have to look at Helium filled balloons to see how well it contains light gas [yes some helium will leek out of the seal, but if you did a back-to-back test with air filled balloons the result speaks for itself.............rubber is permeable [but contains Nitrogen pretty well]].

Looking at Nitrogen, Oxygen and air:

Nitrogen:
Density - 1.165 kg/m^3
Atomic weight - 14.0067 U

Oxygen:
Density - 1.331 kg/m^3
Atomic weight - 15.9994 U

Air(78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide (http://en.wikipedia.org/wiki/Earth's_atmosphere)):
Density - 1.205 kg/m^3

References:
http://www.engineeringtoolbox.com/gas-density-d_158.html
http://www.webelements.com/


So let's put an end to this non-sense that nitrogen is more dense than air and oxygen. It isn't.
What I do not know, can not easily find and can't be arse calculating is the molecular cross-section of the two molecules, this matters when considering diffusion through permeable media.

Yes, using a purified and completely dry gas could make a difference in regards to consistency - something which is very important in all scientific pursuits (e.g. F1). Also, I can not imagine any downsides to putting pute nitrogen (not liquid mind) in tyres compared to normal air. Worth $5 a tyre? I don't think so...


Any of the "non-believers".

I think this strikes closer to the heart of the matter. For everyday motoring the belief-factor of having nitrogen filled tyres is probably a few orders of magnitude more influential than the physical side of things.

[Badjelly]

the big question is... for Joe public like me is there any advantage/dis advantage to using the nitrogen or world we not notice any difference??

my guess is that no difference would be noted by joe public

Well, given that Joe Public isn't very observant, this a bit of a loaded question, but...

I think the only difference you might notice is that your tyres wouldn't lose pressure quite so quickly.

[Devil]

the big question is... for Joe public like me is there any advantage/dis advantage to using the nitrogen or world we not notice any difference??

my guess is that no difference would be noted by joe public

For Joe Public (bike rider in particular). You probably wouldn't notice a difference.
For high mileage vehicle, commercial driver, you're most likely to see the benefits.

I dont use it, I dont have a need for it.

[Sully60]

My, this is quite the disscussion considering it's about inert gas.

Imagine how it would go if we used Ununoctium somewhere in our motorcycles:rolleyes:

[ManDownUnder]

Does not...Does too...





Looking at Nitrogen, Oxygen and air:

Nitrogen:
Density - 1.165 kg/m^3
Atomic weight - 14.0067 U

Oxygen:
Density - 1.331 kg/m^3
Atomic weight - 15.9994 U

Air(78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide (http://en.wikipedia.org/wiki/Earth's_atmosphere)):
Density - 1.205 kg/m^3

References:
http://www.engineeringtoolbox.com/gas-density-d_158.html
http://www.webelements.com/


So let's put an end to this non-sense that nitrogen is more dense than air and oxygen. It isn't.
Agreed, but ... argh can't be fagged... here - read this (pdf warning) (http://www.getnitrogen.org/pdf/graham.pdf)


What I do not know, can not easily find and can't be arse calculating is the molecular cross-section of the two molecules, this matters when considering diffusion through permeable media.
WOAAAAA there... you're not claiming to know it all - you don't fit in around here at KB do ya man??? LOL (p/t)


Yes, using a purified and completely dry gas could make a difference in regards to consistency - something which is very important in all scientific pursuits (e.g. F1). Also, I can not imagine any downsides to putting pute nitrogen (not liquid mind) in tyres compared to normal air. Worth $5 a tyre? I don't think so...

I think this strikes closer to the heart of the matter. For everyday motoring the belief-factor of having nitrogen filled tyres is probably a few orders of magnitude more influential than the physical side of things.

LOL - total agreement there. The theory being one thing - the practical reality is something compleeeeeetly else. :niceone:

[Badjelly]

So let's put an end to this non-sense that nitrogen is more dense than air and oxygen. It isn't. What I do not know, can not easily find and can't be arse calculating is the molecular cross-section of the two molecules, this matters when considering diffusion through permeable media.

Did anyone say that nitrogen is denser than oxygen? I didn't notice. What someone did say is that it diffuses more slowly. As you say, this is a function of the molecular cross-section. Wikipedia (http://en.wikipedia.org/wiki/Nitrogen) notes that


Nitrogen molecules are less likely to escape from the inside of a tire compared with the traditional air mixture used. Air consists mostly of nitrogen and oxygen. Nitrogen molecules have a larger effective diameter than oxygen molecules and therefore diffuse through porous substances more slowly.
and cites this paper:

http://dx.doi.org/10.1063%2F1.1707667

So there you go. No need for any more discussion of this topic!

[The Stranger]

I did - and combined with the results of the Clemson Uni Study quoted above I'd say you're right - it could leak through the bead or the valve - and it would probably happen about 70% faster with air than Nitrogen.

Thanks for the invitation to think about it... turns out you're wrong on a number of counts. C'est la vie.

Open invite to find a reputable source that says I'm wrong. Prefer peer reviewed/scientific type resources if that's ok. KBers are prone to saying things without actually thinking... or knowing. What're the chances?

My daughter used to get pissed at me for always "winning" our arguments.
The way I would "win" them is to not argue about shit I know nothing about, quite simple really. I would have thought it obvious, but apparently not.

[Mikkel]

Does too...

Does not...


Agreed, but ... argh can't be fagged... here - read this (pdf warning) (http://www.getnitrogen.org/pdf/graham.pdf)

Yep, that was kinda what I was getting at. One thing I do dislike about the pdf-file is that he just says "it actually is" without providing any references.

We used to calculate the length of molecular bonds back during my undergrad years - and the size of molecules very much depends upon this and how tightly bound the electrons of each individual atom are. But, I have forgotten almost all of the details of this by now and I can only recall it was frightfully tedious and that I am glad I don't have to do it for a living.

[Mikkel]

Did anyone say that nitrogen is denser than oxygen? I didn't notice. What someone did say is that it diffuses more slowly. As you say, this is a function of the molecular cross-section. Wikipedia (http://en.wikipedia.org/wiki/Nitrogen) notes that


and cites this paper:

http://dx.doi.org/10.1063%2F1.1707667

So there you go. No need for any more discussion of this topic!

Does not...


In actual fact, if you keep on filling your tyres with air they will eventually siphon all of that nasty oxygen out of your tyre and you'll be left with nitrogen-enriched air in your tyres for free. Coole eh!

[UberRhys]

Yes, using a purified and completely dry gas could make a difference in regards to consistency - something which is very important in all scientific pursuits (e.g. F1). Also, I can not imagine any downsides to putting pute nitrogen (not liquid mind) in tyres compared to normal air.

Now there is a thought... liquid nitrogen filled tyres - choice one... We freeze stuff at work with it all the time. THEN WE SMASH IT for fun of course...:clap:


In actual fact, if you keep on filling your tyres with air they will eventually siphon all of that nasty oxygen out of your tyre and you'll be left with nitrogen-enriched air in your tyres for free. Coole eh!

A very long way to get Nitrogen into tyres, but you will still have the issue of moisture which will expand under heat and allow the pressure to fluctuate.:Pokey:

[varminter]

So.... fill your tires with helium and float over the opposition.
Fill with plutonium and everyone will avoid you
Fill with nuetronium and ride straight to the center of the earth:devil2:

[thepom]

Aircraft use nitrogen in their tires as it is an inert gas and lowers the risk of fires started by hot brakes and the wheels blowing,maybe the same for F1 but hey who is stupid enough to pay for it in their car or bike? not me for one!

[reofix]

Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.

[Dak]

Nitrogen filled tyres are bollocks, except that the air might be drier, so less prone to expansion and contraction. Air is 80% nitrogen anyway.
Try googling "nitrogen filled tires" and read some of the studies.

Exactly, I work at a place that sells the stuff and I agree, for joe average it is BOLLOCKS!

[Devil]

Try googling "nitrogen filled tires" and read some of the studies.

Try googling Nitrogen Tyre research instead and get the actual studies instead of peoples opinions and retarded conclusions.

[Devil]

Exactly, I work at a place that sells the stuff and I agree, for joe average it is BOLLOCKS!

Oh god. seriously. Dont breed.

Because it has little to no discernable effect for joe bloggs, doesn't mean that it doesn't work for others, ie commercial vehicles, for which it is mainly pushed.

Little to no effect on subject X doesn't mean that it doesn't work ever.

Too much opinion and poor conclusions, too little fact.

[2_SL0]

Cant be farked posting an answer. Could use Nitrogen, Dry Air, etc, its the moisture content that is the issue.
Cost wise, Nitrogen is one of the cheapest.
I know of a number of commercial trucking companies that use it in Europe.

[ManDownUnder]

This is a great thread.
Re Nitrogen
Benefit 1) Nitrogen filled tires don't lose pressure so fast because N2 is physically bigger than O2, a consituent of air. Both N2 and O2 and escape through tire walls but N2 does it a lot more slowly
Expense 1) It's costs money to put in there, and more money every time you pump your tires up (What's the point of exluding oxygen at the initial fill then chuck in it as part of the air used to top tires up?)

Re moisture (entirely different topic in my mind
Dry Air or Nitrogen will exclude moisture which expands at temperature therefore tire pressure will be more stable with dry gas then not dried gas.

There's a shitload of posts saying I think this and I think that with fuck all backing them up. Try a little academic research... the Internet is your friend. Look up actual studies, cite some reasearch and it's give you a good argument and (as I have) actually learn something along the way.

Seriously - don't take my advice on this stuff. Google it. Include the words "research" "university" and "study" in the search string, then read the factual results of actual work done to establish the facts.

You might happen to like Bob, but that doesn't make everything he says true.

[98tls]

Why anyone would pay for something when they can achieve the same result for zip is beyond me,then again its Kiwis we are talking about.Possibly a fashion thing? Something to talk about over a latte in Auckland "look at my tires there simply bulging with Nitrogen":yawn:No doubt the school run in the obnoxious never been never will be off-road 4wd will be the much safer with Nitrogen filled hoops.Load of bollocks.

[3umph]

I'm amazed the banter is still going on about this...

The main thing is no major benefit of running it for the general public in bikes is the common thing I have read....

[saltydog]

I'm amazed the banter is still going on about this...


Reckon, why not fill your bloody tyres with expanda foam.

[3umph]

Reckon, why not fill your bloody tyres with expanda foam.

dam good question... why not... would solve the puncture issue

[Dak]

Oh god. seriously. Dont breed.

Because it has little to no discernable effect for joe bloggs, doesn't mean that it doesn't work for others, ie commercial vehicles, for which it is mainly pushed.

Little to no effect on subject X doesn't mean that it doesn't work ever.

Too much opinion and poor conclusions, too little fact.

Really, would you like me to show you the legal papers on how we are governed to sell it? Pushed for commercial vehicles? 90% of the nitrogen sales in this country are done by Fire#$%#, they will try and sell it to your grandmother. It's easy money for them, the profit margin on a bottle of nitrogen is huge.

[Squid69]

Reckon, why not fill your bloody tyres with expanda foam.

You would need to soften your suspension.

The first stone you hit the tyre would not deform and you would probably head into the ditch, perhaps even tankslap into it...

[3umph]

these might be better... airless tyres

http://thekneeslider.com/archives/2005/11/17/michelin-airless-motorcycle-tires/

[Mikkel]

Just before we get carried away, I'd like to point out that any gas -whether wet or dry - will expand (depeding upon the situation the volume or the pressure will rise - or both) in roughly linear proportion to the temperature.
Where wet versus dry comes into the equation is just how roughly.

Ideal gas law (http://en.wikipedia.org/wiki/Ideal_gas_law) - this describes both nitrogen and air fairly well. At least as far as this discussion is concerned.

[Forest]

Well let's look at molecular size then shall we.

For practical purposes, the covalent radius is 50% of the distance between identical covalently bonding nuclei.

Nitrogen's covalent radius is 75 x 10^-12 m so a nitrogen (N2) molecule is approximately 4 x 75 x 10^-12 m = 300 x 10^-12 m.

Similarly an Oxygen molecule (O2) is 4 x 10^-12 m = 292 x 10^-12 m.

So an oxygen molecule is approximately 2.7% smaller than a nitrogen molecule.

Anyone who thinks this makes a difference to tyre inflation is a moron.

[Mikkel]

For practical purposes, the covalent radius is 50% of the distance between identical covalently bonding nuclei.

Nitrogen's covalent radius is 75 x 10^-12 m so a nitrogen (N2) molecule is approximately 4 x 75 x 10^-12 m = 300 x 10^-12 m.

Similarly an Oxygen molecule (O2) is 4 x 10^-12 m = 292 x 10^-12 m.

I could be wrong, but it seems to me that there are a few numbers missing... :scratch:

[Forest]

I could be wrong, but it seems to me that there are a few numbers missing... :scratch:

Oxygen and Nitrogen are just a pair of atoms stuck together by a simple covalent bond.

The overall length of the molecule is therefore four times the corresponding covalent radii.

[Devil]

Really, would you like me to show you the legal papers on how we are governed to sell it? Pushed for commercial vehicles? 90% of the nitrogen sales in this country are done by Fire#$%#, they will try and sell it to your grandmother. It's easy money for them, the profit margin on a bottle of nitrogen is huge.

Well aware, having previously worked at the head office...
Apologies for being mildly harsh...

[Mikkel]

Oxygen and Nitrogen are just a pair of atoms stuck together by a simple covalent bond.

The overall length of the molecule is therefore four times the corresponding covalent radii.

I merely implied that your calculations, for oxygen specifically, seemed to be missing something.

Certainly, the length of the bond is important. But the effective molecular cross-section doesn't just depend upon the length of the molecule - it is after all a 3D structure.

What is most important is the radii of the electron cloud surrounding the individual atoms, in the bonded state, since this will affect the cross-section along each of the 3 dimensions.
Since I can not remember how to calculate this, and I can't be arsed reading up on it, I trust the properly referenced sources that say that nitrogen has the larger molecular cross-section.

[Forest]

What is most important is the radii of the electron cloud surrounding the individual atoms, in the bonded state, since this will affect the cross-section along each of the 3 dimensions.
Since I can not remember how to calculate this, and I can't be arsed reading up on it, I trust the properly referenced sources that say that nitrogen has the larger molecular cross-section.

Nitrogen and Oxygen don't float around as individual atoms at STP. They form bonded covalent molecules i.e. N2 and O2.

But to answer your question, when you're doing physical gas chemistry calculations you use the Van der Waals radius (http://en.wikipedia.org/wiki/Van_der_Waals_radius) to represent the physical size of the individual atoms.

Here are the Van der Waals radii for Nitrogen and Oxygen:

Nitrogen = 1.55 Angstroms
Oxygen = 1.52 Angstroms

The difference is less than 2%.

[3umph]

Geek fight :whistle::whocares:

[elevenhundred]

Geek fight :whistle::whocares:

:stupid: :whocares:

[3umph]

:stupid: :whocares:
me stupid.... na me sensible :whistle:

[Mikkel]

Nitrogen and Oxygen don't float around as individual atoms at STP. They form bonded covalent molecules i.e. N2 and O2.

Why yes indeed they do. Now what - simple - geometric shapes are available if you connect to particles? Just one... O=O/N=N (O2 is a double bond and I believe N2 a triple bond).
Looking along two axes these will have that shape - but looking along the longitudinal axis they'll look like O and N.

Thus, it matters how tightly bound the electrons are to both atoms in the molecule in all of the three dimensions.


Here are the Van der Waals radii for Nitrogen and Oxygen:

Nitrogen = 1.55 Angstroms
Oxygen = 1.52 Angstroms

I assume that these are for the un-bound atoms - not when hooked up in an N2 or O2 molecule. But I am being unreasonable - calculating the precise spatial distribution of the electron cloud for a molecule (even a simple one like O2 and N2) is not trivial. See Wikipedia on Orbital hybridisation for more detail, that's the way to precisely calculate the spatial shape of a molecule.

All I am saying is that you can not argue that only the bond length for the molecule dictates its dynamical cross-section. It's a gross simplification. A wise man once said "Make everything as simple as possible, but not simpler."
Alas, this physical chemistry is not really that simple.

[3umph]

:hitcher::hitcher:

[Mikkel]

:hitcher::hitcher:

Yes, sorry here I'm getting all carried away again :o

Can't help it - and it seems I will never learn :whistle:

[3umph]

Yes, sorry here I'm getting all carried away again :o

Can't help it - and it seems I will never learn :whistle:

looks like you have learnt too much... :niceone::niceone:

[Forest]

I found a fairly definitive answer to this and it appears that I was wrong.

Modern tyres are lined with a coating of polyisobutylene which provides resistance against gas diffusion from within the tyre.

It appears that polyisobutylene is more effective at containing Nitrogen than oxygen and other gases. So a 100% nitrogen filled tyre will in fact go flat at a slighter lower rate than an air filled tyre will.

You can read more about this at the following link:

http://www.composite-agency.com/messages/Pure_nitrogen_in_tyres.pdf

[SARGE]

the big question is... for Joe public like me is there any advantage/dis advantage to using the nitrogen or world we not notice any difference??

my guess is that no difference would be noted by joe public

ok ok ok.. i admit it.. i have filled both my bikes up with Nitrogen...


couple reasons..

i have 2 big street bikes .. i dont commute on them.. work truck takes care of the morning drive.. i only ride once every couple weeks ..Nitrogen keeps a steady pressure so i dont have to worry about it .. wish i could do that with a battery...


second.. normal compressor air is wet.. water is heavy.. nitrogen fills tend to give you a lighter, drier fill.. reducing weight of your wheels. Gyroscopic weight therefore is reduced..its not a set of new hi end carbon wheels but its a start... i'd love to fill my hoops with air thats been put through driers and filters but thats not gonna happen at Firestone or frank Allen or the local servo


THE QUESTION IS, WHERE'S THE WEIGHT?

REDUCING THE WEIGHT OF YOUR WHEELS IS THE MOST IMPORTANT PERFORMANCE CHANGE THAT YOU CAN MAKE TO YOU MOTORCYCLE!

Lighter wheels will make a major difference in the handling of your bike. They will also greatly improve the acceleration and deceleration "braking" of your bike for the following reasons.

Static Weight: Each ounce of reduction of the wheels weight is equivalent to 4 ounces on the sprung part of the bike. Magnesium wheels will normally weigh at least 10 pounds less than your stock aluminum wheels. This is equal to 40 pounds of weight reduction on the bike. That's alot of carbon and titanium.

Dynamic Weight: This is the weight reduction on the rim of the wheel and this is where the ACTION is. EACH OUNCE OF WEIGHT REDUCTION ON THE RIM IS EQUAL TO ABOUT 25 POUNDS OF WEIGHT AT 100 MPH!

This is real weight that must be turned, accelerated, and stopped. As an example, a pair of magnesium wheels will normally reduce the total rim weight of the two wheels by at least 20 ounces. This means that your bike will weigh 500 pounds less at 100 MPH.

At all other speeds the reduction is in relation to the velocity of the bike. As you increase your speed the weight will increase exponentially.

The following formula will enable you to figure for yourself the impact of dynamic weight on your bike.

Given:
V=Speed of your bike in MPH.
D=Diameter, outside of tire in inches.
G=G Force (Times force of gravity)

So: 1 oz. At the surface of the tire at 100 MPH produces a force of 600.37
ounces, or 37.52 pounds.

Force at the rim: Let's say the rim is 2/3 the way from the axle to the surface of the tire. This equates to 17 inches for the wheel and 10 inches total for the tire. To arrive at the percentage, divide 17 by 27 which will give you 63% which is the distance of the rim from the axle in relation to the overall diameter of the wheel and tire.

Multiply the force at the surface by 63%. 1 ounce on the rim is about 23.64 pounds.

REMEMBER! THE MOST IMORTANT PERFORMANCE ADVANTAGE THAT YOU CAN GIVE YOUR BIKE IS LIGHTER WHEELS!


just my opinion ..

[SARGE]

Well let's look at molecular size then shall we.

For practical purposes, the covalent radius is 50% of the distance between identical covalently bonding nuclei.

Nitrogen's covalent radius is 75 x 10^-12 m so a nitrogen (N2) molecule is approximately 4 x 75 x 10^-12 m = 300 x 10^-12 m.

Similarly an Oxygen molecule (O2) is 4 x 10^-12 m = 292 x 10^-12 m.

So an oxygen molecule is approximately 2.7% smaller than a nitrogen molecule.

Anyone who thinks this makes a difference to tyre inflation is a moron.

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