new tires

[RV7A Flyer]

Originally Posted by RV7 To Go

..even when using nitrogen.

OK, is there *really* any significant reason to fill with pure nitrogen in RV tires? Given that air is *already* 80% nitrogen?

I have no plans whatsoever to do this, as checking tires visually and actual pressure every couple of months is really no hardship, and I doubt that the tubes are degrading sufficiently over a few hundred hours of use between changes due to O2 or H2O to make any difference whatsoever, but I'm open to counterarguments

[scsmith]

Originally Posted by RV7A Flyer

OK, is there *really* any significant reason to fill with pure nitrogen in RV tires? Given that air is *already* 80% nitrogen?

Whats more, if you fill with air, and they lose pressure, presumably because the O2 molecules are smaller and they leak out, leaving behind mostly N2, then you refill with air, and again most of the O2 leaks out, leaving behind the N2, in a few fills you would have darn near 100% N2 !!

If a tire can lose more than 20% of its pressure, that means the N2 must also be leaking out.

In either case, I think the justification for spending money on a system to fill with N2, or paying an FBO to fill you with N2, is rather weak. I always thought the primary reason for N2 in tires on big airplanes was for fire suppression in the case of rejected takeoffs where the brakes get so hot that the tires often blow (through a designed-in relief plug). correct me if I am wrong.

[JimWoo50]

Retreaded tires were $100. delivered to my door and they have been very good. Used Flight Special carcasses. Flipped them once. Still using original tubes from Vans and only have to add air once or twice a year.

[gmcjetpilot]

The Nitrogen is DRY and has no H2O or water vapor and changes pressure less with temperature change.

I called a tire manufacture and asked: WHY ARE TUBES were so expensive. The reason?

There are only two manufactures of tubes, and only one in USA. Only Aviation is really using tubes (along bikes, vintage cars and some farm, but farm is going to tubeless quickly). Also the 5.00x5 tube has a right angle metal tube valve stem which is more expensive to make, along with the "schrader valve", which is also apparently made by only a few companies (I am told). Low volume means prices goes up. Is this true? This is what the manufacture said.

[RV7A Flyer]

Originally Posted by gmcjetpilot

The Nitrogen is DRY and has no H2O or water vapor and changes pressure less with temperature change.

Yeah, but...so? We're not driving F1 cars here.

And what do you do when you need to fill a tire? Do you have your own N2 supply in the hangar or, like most people, do you just have a regular old compressor?

I don't think I'd want to install a Nitrogen fill system in my hangar, knowing that a leak can be fatal in very short order (I can't swing a dead cat here at work without hitting a sign warning about Nitrogen suffocation, but we do have some really large dewars of LN ).