Nitrogen Filled Tyres

[philbey]

Clearly written by a moron.

 

 

"Due to the lower sound speed in nitrogen gases..."

 

Nitrogen: 353 m/s

Oxygen: 330 m/s

 

yeh that as well as the fact that road noise has nothing to do with the gas in the tyre transmitting sound waves, it's all about the design of the tread and the noise it's making as it makes and breaks contact with the road~!

 

And I'll just point out that the reason aluminium doesn't corrode a whole lot (in air at least) is the fact that its GOT A NICE FAT NATURAL OXIDE COATING!

 

Dunno how nitrogen ends up with bigger molecules than oxygen given that oxygen has one more proton than nitrogen does....?! figure that out.

[coln72]

Whats saving their tyres is correct tyre pressures. So the nitrogen doesn't leak at the same rate or something? The same effect can be achieved just by checking your tyre pressures half regularly.

 

Think the theory with Nitrogen is that it does not expand at the same rate atmospheric air, leading to more constant tyre pressures. Guess this is a good thing if your truck is doing millions of k's.

[towe001]

I don't know - i just spend my spare time here

 

But i do know is that divers that go deep use nitrogen

 

 

 

 

or is that methane ?

I wouldn't have a clue i don't go that far down....

[irokin]

Dunno how nitrogen ends up with bigger molecules than oxygen given that oxygen has one more proton than nitrogen does....?! figure that out.

 

Well each extra proton pulls the electron cloud in progressively closer until you start a new cloud. Atoms are weird and cool. It does have a lower density than oxygen though.

[curly]

this brings up 5 advantages for nitrogen over air

explosion. surely in 122 years since pnuematic tyres were invented they would have made them so that compressed air doesn't make them explode, ( but possible )

noise, i don't know how ( but possible )

comfort, air will take your tyres from say 30psi to 40psi when hot which is where they are designed to run, nitrogen will stay at 30psi which may be more comfortable but possibly under inflated ( posslble )

vibration, ( bullshit )

stopping rims from deforming, the tyres at operating pressure will be under inflated so i don't care about molecule structure pothole wins everytime so ( absolute bullshit )

it doesn't even mention extra tyre life, if you don't run your base tyre pressure above recommended then this is bullshit as well

i was originally only interested in th spelling

[irokin]

this brings up 5 advantages for nitrogen over air

explosion. surely in 122 years since pnuematic tyres were invented they would have made them so that compressed air doesn't make them explode, ( but possible )

 

Well an explosion is just "a rapid increase in volume and release of energy in an extreme manner". It doesn't necessarily have to involve combustion, but I get what you're saying. Thats the way I read it too, that they were saying because nitrogen (N2, i need sub script damnit) is inert there won't be an explosion from combustion. But I suspect what they meant is that it wont degrade the side walls and cause a catestrophic failure (explosion). This is usually caused by other factors anyway such as low tyre pressure, manufacturing errors etc.

 

Tyres CAN explode though combusion under VERY rare circumstances though, such as after contacting powerlines.

 

 

comfort, air will take your tyres from say 30psi to 40psi when hot which is where they are designed to run, nitrogen will stay at 30psi which may be more comfortable but possibly under inflated ( posslble )

 

10psi increase means the starting (cold) tyre pressure is probably incorrect. In circuit racing we look for around a 4psi pressure increase, then we know our tyre pressures are in the ballpark. Its not like nitrogen doesn't expand with heat as well.

 

Probaby the biggest factor in the extra expansion rate using air is the water vapour. To me that is the ONLY advantage of nitrogen over air, that it is DRY. Because the water vapour levels from different air sources will vary the expansion rates will vary too. If you spent the effort drying air out I see no reason why it wouldn't perform very similarly given that air is 78% nitrogen. Its far easier just to use compressed nitrogen cylinders though. Even so, if you are using a fairly dry air source (say a compressor with a refrigerator dryer) I see absolutely no benifit in road cars using nitrogen. I can understand race teams wanting a super dry gas for race tyres because it helps remove another variable when tuning the car. But you'd have to be right up there in terms of pushing to the extreme. I can't think of any of the club racers I know that use nitrogen.

 

 

i was originally only interested in th spelling

 

Hehe yea, but it made for an awesome debate ;)

[silverra23]

yup.. we use it in v8 supercar land.. all because it is dry, and therefore less susceptible to the random unexpected pressure increases that our tyres would experience if we were using "wet" compressed air.

 

its also used to run the seriously heavy duty rattle guns used in pit stop wheel changes.. in this instance its the lack of oxygen that appeals for them too.. its been known for the rattle guns to spark inside... when the hammer is beating away trying to get the wheels off.. and people worry that the oxygen and the bit of oil in them might make an explosive mix.

 

i always wondered about that since the rattle gun is surrounded externally by outside air... but hey.. better people than me have worked this out ;)

[irokin]

its also used to run the seriously heavy duty rattle guns used in pit stop wheel changes.. in this instance its the lack of oxygen that appeals for them too.. its been known for the rattle guns to spark inside... when the hammer is beating away trying to get the wheels off.. and people worry that the oxygen and the bit of oil in them might make an explosive mix.

 

I always thought the idea there was that you get a shitload more pressure out of a compressed nitrogen cylinder than a air compressor? There's something like 3000psi plus in a nitrogen cylinder. I imagine you have regulators but putting 300psi up the arse of a high end rattle gun is going to get that wheel off faster than compressed air at say 120psi or 180psi. I imagine the dry nature of the nitrogen helps preserve the expensive guns too?

[silverra23]

Definitely the pressure is a factor, but you can buy cylinders of compressed air too, so I think there is more to it than that.

 

As for the rest, all entirely possible. As I mentioned, I was a little dubious about running Nitrogen through them to avoid the "bomb" scenario. so maybe there are a few reasons for it.

[philbey]

Well each extra proton pulls the electron cloud in progressively closer until you start a new cloud. Atoms are weird and cool. It does have a lower density than oxygen though.

 

yeh that's all the spdf stuff isnt it? Chemistry was by no means fun for me and it's been 10 years.

 

It's all to do with the dryness; If you punch the values into the Ideal gas equation rho= P*R*T you'll see that the pressure change is the same for both gasses

Edited February 4, 2010 by philbey

[irokin]

yeh that's all the spdf stuff isnt it? Chemistry was by no means fun for me and it's been 10 years.

 

Yep. I didn't really like chemistry at the time but I do love all kinds of science now. If only I loved it half as much then as I do now.

[7shades]

[irokin]

;)

[philbey]

man, we're nerds.