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I also use a nitrogen-oxygen-argon blend in my tires. It's easily available in most locationsOn fill gas….I have always had good luck with slightly adulterated Nitrogen, say….19% of some other gas?
I run 26-PSI in the (5.00 x 5) mains and 30-PSI in the (4.00 x 5) nose to achieve Vans spring (gear leg) / damper (tire) effect on my RV-9A. Otherwise, I find it's too bouncy for my liking, especially on uneven taxi and runways -- still appear to achieve good even tire wear and tube life by using quality tires and tubes. As far as shimmy goes, with a 22-lbs pull-out torque on the caster, I don't experience any nose shimmy, especially by keeping it trimmed "nose light" for takeoff and holding it off during landings.I also use a nitrogen-oxygen-argon blend in my tires. It's easily available in most locations
Van's says to run the 5.00x5 tires on the -12 at 25 PSI to act as part of the suspension system; I'm sure it's not great for tire and tube life but it does work.
I’ve repaired a few planes with destroyed tubes from that. Show the folded over tube to the owner, same startled face every time. Result, plane gets both tubes changed, & a few times the tires too, because the tube sometimes vulcanizes right to the tire.
DON’T brake hard! See post above…
Been braking hard for 21-years now in the RV-9A that I completed in 2004, and without any problems.
Proper tube installation and ample usage of talcum powder will prevent this.
Anche io.On fill gas….I have always had good luck with slightly adulterated Nitrogen, say….19% of some other gas?
35 PSI because I didn't know any better and that pressure seems to work for me. I was getting ready to make a hole in the wheel fairing but decided to try FOBO instead. It's really a nice system. https://www.amazon.com/dp/B0822G8GYQ. I pump the tires up to 38 or so in the fall knowing the pressure will come down a little in the cooler weather. The FOBO monitors tire temp also and I was amazed at how hot the tire can get in warn weather and long taxi or heavy breaking.
Similar. I have replaced a few ruptured tubes when folks run too low of pressure. We are so spoiled with tubeless tires these days that can take so much abuse. Tube tires cannot.
Pretty tough to get a tube folded over during installation. Not saying inexperienced folks can’t find a way to do it, but suspect the folding is occurring during usage and not installion. They can fold over in use when under inflated and this ultimately leads to pinching and ultimately leaking. I am sure vans recommended pressure is based upon load capacity and don’t argue that 26 meets that criteria. However, one must consider the type of service they will see beyond just load capacity.
Vans does specify a very specific way to install tires and tubes in their manual, which I use myself. And, I tend to see pinched tubes in-between the rims when I help other RV owners fix flats (tubes usually torn right at the rim join). And, if you don't use ample talc and proper inflation technique while installing the tubes, they can get twisted and/or pinched, as Vans also points out in their manual.
I fully agree that pinching tubes between the halves is a real installation issue that happens. I just don't think it is easy to get the tube folded over during installation. The carcass is pretty thick in the relaxed state. Not saying it could never happen; Just don't believe it is common.
Will it tend to shimmy more at higher pressures or no? I am currently at 30.
We tend to have more H2O in ours at sea level. Should I travel to the mountains to get some fresh mountain air and that may help?
Didn't go flat, just rubbed on the pant and pulled a small section off. Did the repairs with carbon fiber and microfill. I had a crosswind get under the wing and push me over a bit too far...
Keri Mi, so whether I am at home or at the hangar, I am with Keri....and I thought of that all by myself! And thanks, I am gonna order some extensions until I get snap caps installed.SO: the consensus is not less than 30 and not more than 50. I would suggest starting with 35 and try that watching for, mostly, shimmy. And landing quality, as Vans would tell you. Go up 5 pounds at a time and see what works for your airplane. The harmonics seems to be different from airplane to airplane so what is good for SuzieQ might not be good for..........what's your airplane's name?......
I have the old wheel fairings (new ones are in the living room!). I figured out where the stem would be and drilled a 1" hole which is covered by a simple snap fitting when not needed. I have the WHEEL marked where the stem will line up with that hole (mark at the bottom when lined up). I stick a piece of rubber hosing in to remove the valve stem cover. I have an extension I screw onto the valve stem and can check pressures and fill to my 35 if necessary. I do not have the $$$expensive$$$ tubes but it is so easy to check pressures and keep them up. I'll spend the money I saved on fuel.
Stems: Amazon
4 PCS Valve Stem Extenders, 4inch 100mm Wheel Tire Valve Stem Extension, Wheel Valve Extension Rod Extender Stem Caps for Trucks Cars Motorcycles Rv Mowers
YMMV but I like this system......
I also use a nitrogen-oxygen-argon blend in my tires. It's easily available in most locations
Van's says to run the 5.00x5 tires on the -12 at 25 PSI to act as part of the suspension system; I'm sure it's not great for tire and tube life but it does work.
You can not just blunty look at "design" pressure, if there even is such a thing. The same set up runs on oleo gears as well as bungee as our spring steel rod. each brings it's own vibration, shimmy, not to mention difference in weight. The first Rv forum I was on was the Matronics list. Every few years a new generation of RV builders. Not out of the aviation trade, like Van himself (trained Aeronautical engineer) but some non related field. [ed. Removed political sentence. Please observe the posting rules. dr]
Well -- at 40-psi and expecting to land hard at times, then you better plan on some big bounces and stay proficient at your go-arounds. The damping effect is all but gone in a normally designed for spring/damper landing gear system. Shock absorbers have both spring and damper for a very good reason! Perhaps sticking with a primary trainer until learning how to land would be a better idea!
I inflate all three tires to 50 psi on my 9A. I have not had a bounce problem. Reduced risk of flats at the higher pressure.Well -- at 40-psi and expecting to land hard at times, then you better plan on some big bounces and stay proficient at your go-arounds. The damping effect is all but gone in a normally designed for spring/damper landing gear system. Shock absorbers have both spring and damper for a very good reason! Perhaps sticking with a primary trainer until learning how to land would be a better idea!
Well -- then it sounds like you're a very good pilot and know how to land an airplane! Been running 28-psi in the mains and 30-psi in the nose, and I have never experienced a tire or tube failure in over 21-years of flying my RV-9A regularly. However, I use high quality tires and tubes (Michelin or Goodyear) and follow Vans tire/tube installation procedures "to the letter", which is VERY important even if you run 50-psi. And, I would venture to say -- if you get a puncture during takeoff or landing at 50-psi, you're more likely to experience a blow-out than simply going soft.
Vans is not boeing. For years he told us vne was in ias; only later he realized his error, or later understood unforeseen consequences, and changed it. Vans put a tail on the 7 that didn’t have favorable results and changed it. Think the world of van and hold his skill in high regard, but that doesn’t make me think he nailed the tire pressure recommendation, especially when pilots with skills lesser than his own are using the planes. Clearly The recommended pressure will handle the load, but one must consider what happens when that lower pressure creates excessive deflection, especially in a tube tire. While many can get away with running those pressures, i firmly believe many cannot.
If Vans was Boeing, there wouldn't be this discussion, it would be a certified aircraft and you'd have to comply with regulations and approved maintenance data.
Your mathematics are doubtful, the aircraft still has forward motion and thus lift. I doubt a RV will survive a 3.7G impact as in the aircraft is still useable without repairs.
FWIW, on my 4th landing since new to the RV-8, I oopsed and did a 3,1 G (Dynon Data) stalled, carrier landing at 1800 lbs.
The original tail was an 8 tail and van didn’t like the spin recovery so moved to the 9 tail. He felt strongly enough that he offered the new tails to builders with the original for free.
RV-6A here 360 cs prop I run 45 never had a problem
