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  #11  
Old 11-16-2017, 01:34 PM
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AndyRV7 AndyRV7 is offline
 
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Location: Hudson County, NJ
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I've not landed one per se but I've had 3 flats after landing. One time I taxied back to do another lap and couldn't get the plane to move. Another time it happened in the hangar overnight. The last one was last weekend. Landed and taxied to the hangar and was able to drag the plane back in the hangar as the last air left the tire. I was lucky to be on my home field for all three.

The reason I am posting is because all three times seemed to be from low pressure in the tires. I've run them between 25 and 35 psi over my few years of ownership, while I've tried to pick a favorite. All three tubes had a small sidewall pinhole caused by wear. Twice, the last bit of tube gave up on a flight (or more likely a landing) in November just after the first real cold snap. I'm sure the tires had worn all along but the lower pressure on the first cold morning seemed to be enough too allow the tube to rub against the tire sidewall and cause the inevitable slow leak. Just food for thought.

I too am happy to hear the landings were easily controlled!
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  #12  
Old 11-25-2017, 10:02 AM
Ted RV8 Ted RV8 is offline
 
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Location: Northern CA
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Default Tires

What are thoughts on different tires and number of ply.

A friend who raced at Reno used to run ten ply tires for two reasons. One could run real high pressure for faster roll out on race start. Two if tire pressure got low the ten ply tire could support the airplane better with less chance of tube failure.

Thoughts? Any body running 8 or 10 ply tires on their RV?

Last edited by Ted RV8 : 11-25-2017 at 09:34 PM.
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  #13  
Old 11-25-2017, 02:24 PM
rvbuilder2002 rvbuilder2002 is offline
 
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I am not aware of any, and I am not sure the trade-offs would be worth it.

There are a lot of different engineering aspects of aircraft design that anyone without formal training would not be aware of.

The experimental category is great because of the freedoms it provides but very often experimenting happens in blissful ignorance (before criticizing me for the use of the word ignorance, please look up the definition).

Tires are an important part of the landing gear system. They provide a lot of energy absorption (when needed). Take note of the amount of tire deflection in the slomo portions of THIS VIDEO as an example.

If you use stiffer tires (because of higher pressures or more plys), they are absorbing less energy. That means more energy gets transmitted into the gear leg and possible the aircraft structure itself.

A disheartening example is an RV-10 project that recently dropped 4 feet to the hangar floor when a lift failed. The main wheels were restrained by the lift and unable to flex when it hit the floor, so in this case the tires were the only thing available for energy absorption. The abrupt stop on the hangar floor resulted in major damage to the fuselage.
http://www.vansairforce.com/communit...39&postcount=1

I would recommend not experimenting with higher ply rating tires. They will be heavier, cost more, and in the end could possible cause you problems that you may never have imagined.
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  #14  
Old 11-25-2017, 09:26 PM
Ted RV8 Ted RV8 is offline
 
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Thank you for the input and insight. I'll stick with the 6 ply tires
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  #15  
Old 12-07-2017, 05:23 PM
Ted RV8 Ted RV8 is offline
 
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Scott, what is the recommended tire pressure for the various models? Been doing a search getting mixed answers.
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  #16  
Old 12-08-2017, 11:49 AM
rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by Ted RV8 View Post
Scott, what is the recommended tire pressure for the various models? Been doing a search getting mixed answers.
There is no published recommendation except for the RV-12. It (in most instances) gets built matching a standard... the certified S-LSA.

For all of the others, there is not standard (some people operate at 100 over recommended gross, etc.).
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  #17  
Old 12-08-2017, 09:18 PM
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Blain Blain is offline
 
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Default Pinhole leak

Quote:
Originally Posted by AndyRV7 View Post

All three tubes had a small sidewall pinhole caused by wear. d!
Any idea what causes a sidewall pinhole? I had one a few weeks ago. It troubles me when I canít determine a cause.
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  #18  
Old 12-09-2017, 12:45 PM
rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by Blain View Post
Any idea what causes a sidewall pinhole? I had one a few weeks ago. It troubles me when I canít determine a cause.
It is usually attributed to rub abrasion between the tube and the interior of the tire (if you inspect the interior of a tire closely, it is quite rough and abrasive).

The typical cause is lack of lubrication (not enough talc), and/or to low of a tire pressure which causes excessive side wall flex (and a lot more movement of the tube within the tire).

When I install new tires/tubes, I heavily coat the interior of the tire and I lightly inflate the tube and rub talc over its entire exterior before inserting it in the tire.
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  #19  
Old Today, 08:46 AM
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AndyRV7 AndyRV7 is offline
 
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Quote:
Originally Posted by Blain View Post
Any idea what causes a sidewall pinhole? I had one a few weeks ago. It troubles me when I canít determine a cause.
I think it's just normal wear. The tube is independent of the tire so there is inevitable movement between the two. I think this can be exacerbated by having lower inflation pressures. That's only an opinion though. At some point the tube is going to wear through regardless. As far as talc goes, I think there is only so much you can do. If you've ever changed a tube and used talc, once the surface is covered, the rest of the talc just sits in a pile at the bottom of the tire, presumably going to waste. So really no sense adding a cup full.
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  #20  
Old Today, 11:51 AM
rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by AndyRV7 View Post
I think it's just normal wear. The tube is independent of the tire so there is inevitable movement between the two. I think this can be exacerbated by having lower inflation pressures. That's only an opinion though. At some point the tube is going to wear through regardless. As far as talc goes, I think there is only so much you can do. If you've ever changed a tube and used talc, once the surface is covered, the rest of the talc just sits in a pile at the bottom of the tire, presumably going to waste. So really no sense adding a cup full.
Like anything with airplanes, we can talk about what to do, but that doesn't mean someone will no how to or will do it correctly.

I have seen the aftermath of numerous tires where not enough talc was used.
It seems logical to me that someone wouldn't assemble the wheel with a pile of talc in the bottom of the tire so I didn't bother mentioning it, but short of it piling up, there is strong evidence that it is beneficial to have it coated heavily.
I actually do dump enough in so that I sometimes have to shake out some excess when finished. This allows tipping the tire on its side and shake it around to coat the sidewall of the tire real well (the most important are to have talc).
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RV-6A (aka "Junkyard Special ")

Last edited by rvbuilder2002 : Today at 11:55 AM.
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