South West Bikers | Motorcycle Forum

in the for sale section there is a dna 50 for sale on ebay and in the description it has the following sentence

'Both tyres are also filled with Nitrogen to increase performance, grip and increase the life span of the tyres'

ive never heard of this before,sounds like a joke to me?!

Well if ya get a puncture on the front lawn the grass will grow quicker around the area
Merv

Mervin wrote:Well if ya get a puncture on the front lawn the grass will grow quicker around the area
Merv

More like if you had a puncture, you would reach heaven very quickly , cause don't that stuff explode, the same as helium ??

Nitrogen is a more temperature stable gas, so pressure does not increase/decrease as much due to tyre temperature change

Ok, That auction is for my brothers DNA 50cc. I have told him to remove it.

As an engineer i can tell you that on most road cars it is not worth it. The reason why they use it in racing is to prevent extra combustion due to more oxygen. That means if a tyre bursts and there is something flammable near by the pressure released from the type shouldn't affect it.

On the road it has a placebo and hype effects. It may improve handling/performance because you believe it does. Some people argue that there is less moisture in the air thus less internal corrosion. But c'mon the tyres are made of a polymer to start off so they won't corrode and on cars the rims are contatly weathered on the outside.

Here is my brothers scooter:

http://cgi.ebay.co.uk/2005-GILERA-DNA-5 ... dZViewItem

TLS-Moose wrote:Nitrogen is a more temperature stable gas, so pressure does not increase/decrease as much due to tyre temperature change

that was the reason I understood to be true, however, I belive (and a nasa scientist may be along soon to say I'm talking crap) on a molecular level Nitrogen is 'smaller' than compressed air and so has a habit of passing through the tyre and so loosing pressure over time.

Why not use helium to reduce unsprung weight.

But seriously someone must have tried it.

i was on the understanding nitro had a more open partical structure.. holding the profile of the tyre better.. .
also i read somewhere with just nitro in your tyre, theres no density changes as with oxygen and moisture. as moose said..
untill its free at the garage il stick to air..

Right i am back again. The air is composed of approximately
79% nitrogen and 18% oxygen and the remainder, is carbon dioxide and argon and other gases. The means a majority of your tyre is already nitrogen!!!

Nitrogen is still a gas and affected by temperature. It can be modelled as an ideal gas and it will still have a change in density with a change in temperature but not as much as air.

Nitrogen is a larger molecule type than oxygen or argon pressure fall more slowly. However again most of the gas in a tyre is nitrogen anyways so i wouldn't have thought it was significant in everyday life.

A little bit of GCSE chemistry: Oxygen has more protons/electrons than nitrogen but as nitrogen has more protons, it has a more positive nucleus to attract the electrons. There is no additional shielding hence nitrogen is a larger molecule than oxygen.

However for racing,

Quote: Increasing a tyre's inflation pressure has the affect of reducing the size of its contact patch. Reducing the size of a tyre's contact patch reduces its maximum grip levels. In examples #1 & #2, this is not a problem. In circuit racing applications the pressure build-up experienced when tyres are inflated with compressed air means that grip levels will drop as the tyres heat-up. Reduced grip levels will produce slower lap times. There is some pressure build-up when circuit race tyres are inflated with nitrogen, but the amount is low compared with tyres that are inflated with compressed air.

For the amount of extra money you pay I wouldn't bother filling with nitrogen, just find a friendly fridge engineer and ask him to fill em up. For what it is worth you don't feel any difference, also nitrogen requires more activation enrgy so it actually takes longer to warm up.

A little bit of GCSE chemistry: Oxygen has more protons/electrons than nitrogen but as nitrogen has more protons, it has a more positive nucleus to attract the electrons. There is no additional shielding hence nitrogen is a larger molecule than oxygen.

Oxygen is more stable due to it's extra electron on it's outer shell which is why nitrogen is a more unstable (easier to light) gas...but only just.

More like if you had a puncture, you would reach heaven very quickly , cause don't that stuff explode, the same as helium ??

Helium is number 2 on the periodic meaning it has two electrons in it's outer shell, this makes it incredibly stable and is the reason it is used in blimps now and not hydrogen.

speedy(delboy) wrote:

Mervin wrote:Well if ya get a puncture on the front lawn the grass will grow quicker around the area
Merv

More like if you had a puncture, you would reach heaven very quickly , cause don't that stuff explode, the same as helium ??

I think you're getting mixed up with Hydrogen. Helium is an intert gas & isn't flammable. Likewise with nitrogen, it's the oxygen content in air which is most volotile.

Ricky_t wrote:The air is composed of approximately
79% nitrogen and 18% oxygen and the remainder, is carbon dioxide and argon and other gases. The means a majority of your tyre is already nitrogen!!!

Air is made up of mainly 21% oxygen & 79% nitrogen, there is a very small amount of other gases, but these are so small that this is how the compersition is mainly defined.
Interestingly each breath we take we only metabolise around 4% of the oxygen in air.

Actually ,

There are a number of atmospheric gases which make up air. The main gases are nitrogen and oxygen, which make up 78% and 21% of the volume of air respectively. The remaining 1% of the atmospheric gases is made up of trace gases (such as carbon dioxide)

And if you want to be extremely precise ...
Nitrogen - 78.09%
Oxygen - 20.95%
Argon - 0.93%.
Carbon Dioxide - .02% -.04%
Neon - .0018%.
Helium - .0005%
Krypton - .0001%
Hydrogen - .0005%
Xenon - .000008%
Ozone - .000002%
Radon - Traces

Some links for more in depth explanation (why fill tyres with nitrogen)

http://www.msgroup.org/forums/mtt/topic ... s=nitrogen

http://www.parker.com/ead/cm2.asp?cmid=8411

http://www.prosep.co.uk/tyresaver-pr.htm

ive just got back from nasa today,,
i passed my degree..
thanks to all the above info..
im just going to rest my head now ...
theres a load of gumpth in the back off demon tweeks cat..!!