What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

RV 8 wheels

6

67pileit

Member
I'm thinking of buying an RV8 and would like to operate it into a rough grass strip. A friend with an RV4 has flown his aircraft into the stirp and says the vibration is too hard on the airframe. Can one put larger tires/wheels onto an RV8 to sovle this problem? Thanks
 
two options

Hi,
welcome to the forum, first of all!

There are other threads in the archive on this topic, but I will summarize for you:

A few people have put 600 x 6 wheels and tires on. I think it may be tough to fit the wheel pants on such big wheels, but if you are frequnting rough fields, you probably don't want the spats on anyway.

A middle option is to use somewhat bigger tires on the standard 5" wheels. Folks are using the 380 x 150 x 5 tires, which are about an inch bigger in diameter and a fair bit wider too. This provides a pretty significant increase in tire, but still fits in the wheel pants, is easy to switch back to std tires if you like in the future. This is what I am doing.

I positioned my wheel pants about 1/2" higher than the instructions say, so that the 380x150x5 tires will fit inside, and the combination of the higher fit and the bigger tire gives lots of clearance from the wheel pant to the ground, so it doesn't get beat up on gravel, grass, etc. Would still be vulnerable in very soft/muddy situations, but I hope those are very rare for me.

Also, if you plan on a lot of rough field ops, I strongly recommend you substitute the stronger nuts on the landing gear leg attachment bolts. There is a very long thread on that topic, you will have to sort through the chaff to get to the important info, but could search on NAS1804-6 to get you started.
 
Chris,
Using 6" wheels requires using 1.5" diameter axles. Your 8 comes with 5" wheels, which use 1.25" diameter axles. The RV8 is the only 2 seat model of the RV line, which allows you to change out the axles.
So the answer is YES, you can put 6" wheels on your 8. You will need to replace your axles to do it.
Charlie Kuss
 
One other thing to remember is that you friend with the -4 has a completely different type of landing gear arrangement than on an -8. The -4 has a rod-shaped gear attached to the engine mount, and the -8 has a flat steel gear mounted to the fuselage. While I agree that the stock airplane is not ideally suited to rough fields, I would be hesitant to take action simply based on comparisons to the -4....the first time I saw one taxi up to me on a rough grass strip and I saw the springiness of the gear and the way the wheel move relative to the airplane, it scared the heck out of me! The -8's gear doesn't bounce around in quite the same fashion.

Paul
 
67pileit

Good advice above.

We have the 380x150x5 tyres... and they can be run from 15psi to 35psi according to what you want/need.

Given your initial concern <<and says the vibration is too hard on the airframe>> low pressure should help... However, once you have swppaed the main tyres as above, the tailwheel becomes an issue. The aft end of RVs can crease / take a beating. Similarly, 2 up our RV-8 causes more strip damage / furrowing from the tailwheel than the main wheels.

Summary: the 380x150x5 tyres are an "easy" modification, in fact, hardly that. If you need to go to 6" wheels / tyres, you might need to look at a "fat / low pressure" tailwheel as well?

Andy
RV-8 G-HILZ
 
Check the nose gear!

You might want to research the nose gear issues that RVs have been having, also.
You may think twice about operating an 8A on a rough or unimproved strip.
 
Not nose gear...

sf3543 said:
You might want to research the nose gear issues that RVs have been having, also.
You may think twice about operating an 8A on a rough or unimproved strip.
Click to expand...

Um, sorry, but the question that started the thread was regarding an RV8, not an "A"
 
Further to Paul's post, the RV-4 has had issues with the gear/engine mount cracking, either through apparent heavy landings or general abuse i.e. rough field. The RV-8 will not have this exact issue... It might be worth clarifying
A friend with an RV4 .... and says the vibration is too hard on the airframe
Click to expand...
the exact basis for his assessment? Is it RV generic? Or specific to the cracking issue?
 
Thank you all for your inputs. My first time doing this and I am at the bottom of the power curve. I'm very impressed.:)

Chris
 
How does the -8 gear compare?

Ironflight said:
One other thing to remember is that you friend with the -4 has a completely different type of landing gear arrangement than on an -8. The -4 has a rod-shaped gear attached to the engine mount, and the -8 has a flat steel gear mounted to the fuselage. While I agree that the stock airplane is not ideally suited to rough fields, I would be hesitant to take action simply based on comparisons to the -4....the first time I saw one taxi up to me on a rough grass strip and I saw the springiness of the gear and the way the wheel move relative to the airplane, it scared the heck out of me! The -8's gear doesn't bounce around in quite the same fashion.

Paul
Click to expand...

Paul,

As the risk of starting a war, do you think the RV-8 style gear definitely handles rough fields better than the tapered rod traditional style?

I would really like to know!

Thanks,
Andrew.
 
Kiwi said:
Paul,

As the risk of starting a war, do you think the RV-8 style gear definitely handles rough fields better than the tapered rod traditional style?

I would really like to know!

Thanks,
Andrew.
Click to expand...

Andrew:

All I can say is consider the Cessna 180/185 -- pretty much the archetype for rough fields in Alaska. It uses the same style gear (flat steel) as the RV-8.

Chris
 
I keep finding these old threads with very good info for my newly purchased RV-8 and my grass runway, thanks !
 
scsmith said:
A middle option is to use somewhat bigger tires on the standard 5" wheels. Folks are using the 380 x 150 x 5 tires, which are about an inch bigger in diameter and a fair bit wider too. This provides a pretty significant increase in tire, but still fits in the wheel pants, is easy to switch back to std tires if you like in the future. This is what I am doing.

I positioned my wheel pants about 1/2" higher than the instructions say, so that the 380x150x5 tires will fit inside, and the combination of the higher fit and the bigger tire gives lots of clearance from the wheel pant to the ground, so it doesn't get beat up on gravel, grass, etc. Would still be vulnerable in very soft/muddy situations, but I hope those are very rare for me.
Click to expand...

What size inner tubes do you use on the 380x150-5 tires?
 
Pilot135pd said:
While he answers, I read on another forum they?re using the same tube since it?s almost the same size and tubes expand so much.
Click to expand...

Muchas gracias Carlos. I figured it might be the same tubes but just wanted to make sure. Just moved La Otra Chica to my new grass strip at TN26 and it's not as smooth as I'd like it just yet. Spent all day yesterday riding around on a motorized roller that helped a bit. Pretty sure it'll get better as the Bermuda grass continues to get established. In the mean time I was looking at putting the larger tires on.
 
Larco said:
This might be worth some consideration too.
https://www.flyboyaccessories.com/product-p/1152.htm
Click to expand...

Thanks. Already swapped out the tail wheel fork with the Screaming Eagle fork and put the Lightweight Tailwheel on. With this combination I get slightly better visibility over the nose as the tail gets raised slightly, and also increase the safety margin if I happen to hit any ruts. I like the idea of the pneumatic tailwheel but by their own admission it has a propensity to go flat so I passed on that.
 
Last edited:
Carlos151 said:
Muchas gracias Carlos. I figured it might be the same tubes but just wanted to make sure. Just moved La Otra Chica to my new grass strip at TN26 and it's not as smooth as I'd like it just yet. Spent all day yesterday riding around on a motorized roller that helped a bit. Pretty sure it'll get better as the Bermuda grass continues to get established. In the mean time I was looking at putting the larger tires on.
Click to expand...

I have my demons with the grass runway too and never feel it?s as smooth as I want it. I?ve noticed that where there are missing patches of Bermuda grass or bald spots that?s where it doesn?t seem smooth enough. It?ll get better.
 
You must log in or register to reply here.
Back
Top