Nitrogen in tires...

[Jordo]

Originally Posted by ard

That is ABSOLUTELY FALSE.

It has been repeated and believed like an internet rumor, but is just false.

Nitrogen, like air, obeys the ideal gas law. It cannot escape this reality:

PV=nRT


End of story. But the back story:

Uncontrolled fill in tires includes moisture. Although atmospheric gases follow the ideal gas law, MOISTURE does not and will create pressure variations as it heats.

When race cars, aircraft tires are filled with 99.99% pure technical nitrogen, care is taken to eliminate any moisture. Great.

Unfortunately this "moisture free' condition is not assured with commercial 94% pure nitrogen generators. They take a truth (race cars abd jets use 99.9% pure, moisture free nitrogen) and use just the nitrogen part (94% with limited moisture control) to convince people ALL the benefits will be included.

Even sillier are the claims of safety, tire life, never needing to check air pressure, etc...

I disagree. Nitrogen is used in suspension componits for the benifit, of its ability to not change in pressure from hot to cold. (well some change, but much less then norm. compressed air) I worked in a -performance only- suspension and motor shop for a few years building Motocross suspension.
Im positive nitrogen has this property. But I will say that we do keep the bladders that we fill is 99.9% pure, moisture free nitrogen.

The bladder is the black rubber piece in the bottom right corner.



^^^ In this case the the "gas under pressure" is the nitrogen that is held in a rubber blader, to keep it from being contaiminated by any oil that may be present. As the shock heats up to over 300* that heat would drasticly change the propertys of how the shock worked, if the bladder was filled with comp. air. Filling it with nitrogen keeps the shock working consistantly from first using it and its cold, all the way up to OP temps.







(I'm bad speller... sorry)