Hi.
has anyone heard or used nitrogen to inflate tyres. I was getting new tyres for the wifes cage (car) and they recon inflating with nitrogen promotes longer tyre life, improved economy, etc. is it a gimmic or could it be benificial?

P.s ride safely all.

Nitrogen molecules are bigger than oxygen molecules. Therefore they can not escape as fast as oxygen does . The tire remains a much longer time on the right pressure.
Second advantage is that nitrogen needs more energy to increase by 1°C as oxygen does. So you don't overheat your wheels that fast.

Cool (no pun intended.lol) thanks mate

Its a much better way to go.No pressure changes as the tire warms up,seems to hold tire pressure forever,no harm in adding air if need be.We use it at our shop.

Well thats the physics out of the way but I wonder what the effect on the design parameters of road tyres really is.

The tyre manufacturers set pressures cold so they have set assumptions that the tyres will heat up (so no change there) and that the pressure will increase (think of sidewall flex and tread pattern distortion here) ............. so if as partsguy says 'no pressure changes', would you really get the tyre working as the manufacturer intended with no pressure change?

In race conditions I can see advantages, on the road my view is that improved tyre life and better economy can best be achieved by simply checking the tyre pressures on a very regular basis.

I'm using a special mixture of about 78% nitrogen and 20% Oxygen with a few other things mixed in like krypton (for good luck). In laymans terms I call this mixture "air". One of the big advantages of nitrogen is that it's dry, air from a compressor most likely is humid, unless you have a good dryer on it, not many people do. There is an advantage if you have a small shop/garage, it means you don't need a noisy air compressor, just a few bottles of nitrogen which are quiet. For most street cars and bikes nitrogen won't make much of a difference.
+1 to what the Duck said about checking your tires.

If your tire lasts a long time it will end up with mostly Nitrogen anyway as the other gases will have leaked out. As far as not heating up as much it should help the tire last longer. I've had tires last a thousand or more miles in the winter as opposed to the summer aka Piralli Strada.

Originally Posted by TheDuck

Well thats the physics out of the way but I wonder what the effect on the design parameters of road tyres really is.

The tyre manufacturers set pressures cold so they have set assumptions that the tyres will heat up (so no change there) and that the pressure will increase (think of sidewall flex and tread pattern distortion here) ............. so if as partsguy says 'no pressure changes', would you really get the tyre working as the manufacturer intended with no pressure change?

In race conditions I can see advantages, on the road my view is that improved tyre life and better economy can best be achieved by simply checking the tyre pressures on a very regular basis.

Forgive me pete...

But wouldnt you simply set the pressure in the tyre for the expected pressure when the tyre is hot. meaning if i like my tyre best when they are 38 cold and this increases to 41 when hot, would I not just put 41 in and be done with it. And couldnt this then also help when the rubber is cold as it has the same pressure against the side walls possible preventing sidewall squirm (for want of a better word) as they would when hot pressure was achieved.

Originally Posted by Uglystick

Forgive me pete...

But wouldnt you simply set the pressure in the tyre for the expected pressure when the tyre is hot. meaning if i like my tyre best when they are 38 cold and this increases to 41 when hot, would I not just put 41 in and be done with it. And couldnt this then also help when the rubber is cold as it has the same pressure against the side walls possible preventing sidewall squirm (for want of a better word) as they would when hot pressure was achieved.

Yes you are right, but so far nobody has picked up on the ‘manual’ changing of the pressure to what you want rather than just sticking to the ‘book numbers’. Mr Honda says 42psi front and rear, we don’t all follow that.

The point I was making is that tyre manufacturers set a cold pressure knowing that the tyre will heat up with use and the pressure will rise. Obviously this will vary slightly due to ambient temperatures but the variation should be relatively small.

If a medium is used that doesn’t ‘work’ in the same way as air and there is no pressure increase the tyre will not be working as intended (although I expect the manufacturers test various pressures and see how the tyre performs) so if the pressure is ‘low’ more squirming / wear could occur, or the tyre might get hotter .......... lots of possibilities.

Tyre design has improved no end in the 15 years since the Bird first hit the roads but I note on manufacturers websites that those that give pressures still give 42 / 42 cold for the Bird and for other bikes the same tyres (type and size) run different pressures (as ‘set’ by the manufacturers) suggesting that it is the wheel weights and weight distribution that is the most important factor, hence the pressure remaining the same.

I was under the impression that nitrogen was used in airliner tires because it is dryer and will not induce the same vapour condensation inside the tires when they return from the -40 temperature encountered at 30,000 feet.

Originally Posted by Shewie

I was under the impression that nitrogen was used in airliner tires because it is dryer and will not induce the same vapour condensation inside the tires when they return from the -40 temperature encountered at 30,000 feet.

We use nitrogen in aircraft primarily to reduce the risk of explosion in the event of a brake fire or tyre blow out, it's stability and dryness are important, but secondary.......