Tire pressures

[Ferreip]

Did a search for tire pressures, and similar to "what oil to use", there are many different opinions, but for a -9, is 35 psi a good overall pressure to inflate the tires?

Paul

 

[bjdecker]

It depends on what you want.

Reduced rolling resistance, longer stopping distance, lower tire wear, firmer landings on hard surfaces -- Run higher pressure 45 - 50psi
Increased rolling resistance, shorter stopping distance, higher tire wear, cushier landings on hard surfaces -- run lower pressure 35 - 40psi

Lower pressure can cause the tire to do unpleasant things when sideloaded.

FWIW, I run my RV-7 at ~50PSI.

 

[flysrv10]

Attached is a guide based on number of tire plys.

 

[Sam Buchanan]

Attached is a guide based on number of tire plys.

That is for max rated load. Does a RV-9 load the tires to max?

 

[Cth6]

40 in my 9a on all 3 corners.

 

[plehrke]

That is for max rated load. Does a RV-9 load the tires to max?

Only if they have a TOGW of approximately 3000 lbs.

 

[rv8ch]

I've had a few "firm" landings which I believe didn't result in a flat because I keep my tires up at between 45 and 50 psi. Ok, I've had more than a few firm landings... I'm not really seeing a reason to run lower tire pressure.

 

[Dugaru]

Did a search for tire pressures, and similar to "what oil to use", there are many different opinions, but for a -9, is 35 psi a good overall pressure to inflate the tires?

Paul

I have run 45 psi in all of mine for many years now and that seems to work great.

 

[RV6_flyer]

After 26-years RV-6 flying, I tend to inflate on how the tires look. I like the outside rib of the tire to just touch the ground. In the past, that has tended to be between 35 and 42 PSI. Typically I find 30 PSI too low and too high of rolling resistance. Changing tires tend to be a few pounds more or less from what the old ones use to use.

Your tire pressure may be more or less what everyone else is using.

 

[airguy]

Running too low pressure will also create more tire flexing and rubbing of the inner tube, resulting in abraded spots that leak, and you'll have a flat at some point.

I used to run about 30 psi, got tired of flats and replacing inner tubes, changed to Michelin Airstops ($$!!) and keep mine at 45-50 psi now. No more flats in the last 1000 hours with that.

 

[Ferreip]

Thanks everyone for your answers; I'm going to try running 45 psi. Appreciate your recommendations.

Paul

 

[plehrke]

Thanks everyone for your answers; I'm going to try running 45 psi. Appreciate your recommendations.

Paul

Just be prepared for potential main gear vibration. Higher pressures reduce gear leg dampening. I ran 32-35 psi for 15 years and never had and gear vibration. Based on posts here, I increased my pressures to 38-40 and got some pretty significant main gear vibration. I have since added wood strips to my main gear legs to act as dampeners. Now I am running 35-38 psi with no issues. I will probably let it migrate to 40 psi as the weather heats up (and tire pressure increases with the temp) but don’t feel the need to go above 40.

 

[airguy]

Just be prepared for potential main gear vibration. Higher pressures reduce gear leg dampening. I ran 32-35 psi for 15 years and never had and gear vibration. Based on posts here, I increased my pressures to 38-40 and got some pretty significant main gear vibration. I have since added wood strips to my main gear legs to act as dampeners. Now I am running 35-38 psi with no issues. I will probably let it migrate to 40 psi as the weather heats up (and tire pressure increases with the temp) but don’t feel the need to go above 40.

Truth.

My nose gear has a "taxi-too-fast" alarm that now goes off at exactly 18 knots groundspeed with tire pressure at 45 or above.