Flat tires ?

[Ironflight]

I buy my Michelin tubes from the same place I buy my retreaded tires - Desser. I rarely find them any place cheaper.

Paul

[L.Adamson]

Originally Posted by flyvans.com

having problems with the default van's tubes... airplane is sitting in the shop but both main wheels loose pressure over about a half a year. went from 30psi to 7in each :-(

anyone have the source, part #, size etc... for the michelin air stop tubes that are being recommended?

thanks a lot,

kind regards,
bernie

Before I started flying the plane, the tubes would loose air much faster. As to why?

L.Adamson -- RV6A

[flyvans.com]

Originally Posted by L.Adamson

Before I started flying the plane, the tubes would loose air much faster. As to why?

L.Adamson -- RV6A

that's what i'm wondering as well... my car tires barely need one topoff each year or so, why can't the aircraft tires be that way.
also, found out that they loose pressure faster if the safety cap is not on the valve stem. the valve is fine and tight though...
and because of that safety cap requirement, a simple hole for a stem extension in the wheelpants won't do :-(
guess we'll look at removing the wheelpants once a month?!

thanks for any hints/data points...

rgds, bernie

[L.Adamson]

Originally Posted by flyvans.com

the valve is fine and tight though...
and because of that safety cap requirement, a simple hole for a stem extension in the wheelpants won't do :-(
guess we'll look at removing the wheelpants once a month?!

thanks for any hints/data points...

I have a round hole in the wheel pants that line up with the stem, and use an extension. I pull the cap off with needle nose pliers, although some rubber device that clamps around it, might be better. I also found, that I can at least go two months, and perhaps only loose about 5 lbs. It was far quicker than that, when the plane was in the shop.

L.Adamson --- RV6A

[Randy]

Nitrogen may be the answer to the slow leak down process. It is being used more and more in cars these days because it does not leak out through the rubber tubes as easily as air does. I assume this is due to the size of the molecules.

It is a bit of a chore setting up with the right regulator etc. My only experience is with my truck tires. I never have to top them off. It seems the only time they lose pressure is from me checking them.

Any experience here with nitrogen in AC tires?

Randy C

[mannanj]

Originally Posted by flyvans.com

anyone have the source, part #, size etc... for the michelin air stop tubes that are being recommended?

thanks a lot,

kind regards,
bernie

Aircraft Spruce has them in stock.

[alcladrv]

Originally Posted by L.Adamson

How are the tubes and tires that Van's supplies these days holding up?

A fellow RV'er who isn't too familier with this forum has asked me to ask the question. He's had two flat nose wheel tires on his new RV9A with in the last few months. His previous 9A from 2004 never had the problem in the 140 hrs that he flew it.

L.Adamson -- RV6A

On my -7A, I'm still using the original nose tire and tube that Van's supplied 4 years and 450 hrs. ago. For the first year I kept it at 25 psi, but noticed some scuffing on the bottom of the nose wheel pant.

Since then, I've maintained it at 35 psi. After repainting the wheel pant, I notice I still get a little scuffing on the bottom.

My main tires and tubes are also original as supplied by Vans. I had a flat on one wheel apparently because it was under-inflated at 30 psi. After patching the leak on the tube and increasing the pressure to 45 psi, it's still good 2 years and 250 hrs. later. No out of balance issues that I could feel with it.

For me, a medium to higher pressure has worked better than a lower one.

[vlittle]

A couple of days ago, I have a flat on the left main gear of my 9A. Fortunately it was in the hangar.

Today, I changed the tubes in both of the mains. The L main had a leak around a funny square abrasion on the tube. Further investigation showed the remnants of a sticky label inside the tire (Airhawk). The adhesive on the label had hardened due to heat and formed an abrasive that attacked the tube.

I cleaned it all out and installed a new Michelin tube.

The R main was not flat, but I inspected the tube and tire and found the same abrasion and sticky label problem!

Clearly there is a problem here. I don't know where these labels come from, or why they are attached to the inside of the tire, but my guess is that they are "QC OK" type labels... that damage the product!

The original tires/tubes are from Vans.



Now, here's a second problem. After installing the Michelin tubes, I found that the valve core was recessed about 1/8 into the stem, and my pressure gauge and valve extension would not work properly. I could pressurize the tire, but not check pressure or let air out with the valve extension. Very strange, and I'm wondering if anyone else has seen this problem. I will try changing the cores tomorrow.

Cheers,
Vern

[robpar]

Originally Posted by flyvans.com

that's what i'm wondering as well... my car tires barely need one topoff each year or so, why can't the aircraft tires be that way.
rgds, bernie

Automotive tires are Tubeless. Tubeless tires are MUCH better than tube type in all situations. However a 5" Tubeless tire is not a friendly tire to work with. Anyone having experience with tubeless wheelbarrow tires knows this. They are very difficult to re-inflate without special tools if the bead breaks as it likely would on such as small diameter tire.

Car tires are also heavier to reduce leakage. Automotive racing tires with thin side walls leak down much faster than normal street tires. So with small diameter light weight tires we are likely stuck with tubes.

It is interesting to note that the crazy mountain bikers who jump off cliffs are going to tubeless tires to avoid pinching when they drive the tire into the rim after a hard "landing".

Bob Parry