Centramatics -- 16" wheel rim size

[larry b]

My Stream currently has the bias ply 7-15 and I am planning on purchasing 16" aluminum wheels and 235/80-16 radial tires. These are the closest thing I can find to the 7-15 size. Any one else out there running this size tire?

I am planning on having the new tires and wheels balanced. Is there still a need for Centramatic? I am new at this and didn't know there were such a device until reading some of the threads.

I also read in one of the threads that you should be able to see the top of the tire when looking at the trailer from the side. I can't see the top of tires the top of the tire is about 2" up in the fender well. Does this mean I should look into new axles? can't really afford this year!

I am having a ball with my new project, tore out the kitchen counter top this weekend for replacement. Can't wait for spring so I can address the couple leaks I have.

any replies greatly appreciated

Thanks Larry

[ROBERTSUNRUS]

Hi, larry b. Since Airstream and/or the axle manufacturer doesn't balance the brake drums, balancing you tires/wheels doesn't quite do the job. So I for one, use Centramatics to prevent my trailer from shaking to pieces. Without pictures of your trailer it is hard to tell about your axles, but my understanding is if the top of your tire cannot be seen, meaning that the top of your wheel is inline with your wheel well moulding, you need axles.

[Inland RV Center, In]

Originally Posted by larry b

My Stream currently has the bias ply 7-15 and I am planning on purchasing 16" aluminum wheels and 235/80-16 radial tires. These are the closest thing I can find to the 7-15 size. Any one else out there running this size tire?

I am planning on having the new tires and wheels balanced. Is there still a need for Centramatic? I am new at this and didn't know there were such a device until reading some of the threads.

I also read in one of the threads that you should be able to see the top of the tire when looking at the trailer from the side. I can't see the top of tires the top of the tire is about 2" up in the fender well. Does this mean I should look into new axles? can't really afford this year!

I am having a ball with my new project, tore out the kitchen counter top this weekend for replacement. Can't wait for spring so I can address the couple leaks I have.

any replies greatly appreciated

Thanks Larry

Larry.

Having the tires and wheels balanced, is a good start.

But that does not take care of the hub and drum, which are always out of balance.

The running gear should be balanced as an assembly, tire, wheel, hub and drum, but that can rarely be done.

The Centramatic balancers, then, take care of the complete assembly.

All you need to do then is take care of the tire and wheel and the balancers take care of the rest.

Andy

[Inland RV Center, In]

Originally Posted by ROBERTSUNRUS

Hi, larry b. Since Airstream and/or the axle manufacturer doesn't balance the brake drums, balancing you tires/wheels doesn't quite do the job. So I for one, use Centramatics to prevent my trailer from shaking to pieces. Without pictures of your trailer it is hard to tell about your axles, but my understanding is if the top of your tire cannot be seen, meaning that the top of your wheel is inline with your wheel well moulding, you need axles.

Typically, 2 to 3 inches of the tire should be seen, above the top of the wheel, when the trailer is fully loaded.

The less of the tire you can see, the closer the axle is to needing replacement.

That can easily be confirmed by looking at the position of the torsion arm, as well. If it's parallel to the chassis, it's lived it's life.

Andy

[2airishuman]

hi larry

Originally Posted by larry b

My Stream currently has the bias ply 7-15 and I am planning on purchasing 16" aluminum wheels and 235/80-16 radial tires...

u might wanna recheck the size for 16s...

that's a LOT of tire and an 80 series on 16s may have clearance issues BETWEEN the f/r tires...

the diameter of that tire is ~30.8 inches, around 1.5 inches+ LARGER than oems...

now double that for 2 and u really CUT into the clearance (including wheel wells)

225/70 or 225/75 or 235/70 are more likely to fit.

cheers
2air'

[overlander63]

A torsion axle with a 22 degree starting angle will be at a zero angle when at its rated load. It has nothing to do with whether or not it's worn out, according to Henschen. A better test would be to jack up the trailer and measure how much the wheels drop when the load is removed.

[Jammer]

I think you'll find that a 225/75R16 is a closer match. This is a common tire size, widely used, and available in various load ranges, for trailers.

[larry b]

I have looked and the 225/75R16 and it is a closer match to the original 7-15. I can't find these in the Goodyear Marathon or the Maxxis. Do they make this size in a trailer tire? Is it ok to run a truck tire radial? I have looked up some Pirelles and they have a load rating of 2370 pounds X 4. would this work or is it asking for trouble?

[Inland RV Center, In]

Originally Posted by larry b

I have looked and the 225/75R16 and it is a closer match to the original 7-15. I can't find these in the Goodyear Marathon or the Maxxis. Do they make this size in a trailer tire? Is it ok to run a truck tire radial? I have looked up some Pirelles and they have a load rating of 2370 pounds X 4. would this work or is it asking for trouble?

Larry.

Increasing the tire size to a 16 inch, depends on the condition of the axles.

If the rubber rods have given out in the axle, then the oversize tire can get very close to the wheel well, and perhaps hit it, especially when hitting bumps. If that happens, since the wheel wells are plastic, it is possible to create a fire.

Therefore, before you change the tire size, inspect the axles to make sure that they won't cause a problem for you.

You can learn how to check them out by reading the article in Airstream Central, which is a part of this Forums.

Andy

[larry b]

I haven't had a chance to take the wheels off yet to check the axles. I don't think they are as bad as I thought. I have 4" from the bottom of the body trim on the wheel well to the top of the 15" wheel. I thought I read somewhere that I should be able to see the top of the tire when looking at the side of the trailer. I guess I read it wrong.

Do you have any idea if its ok to run a truck Radial tire?

Thanks for the reply

[Inland RV Center, In]

Originally Posted by larry b

I haven't had a chance to take the wheels off yet to check the axles. I don't think they are as bad as I thought. I have 4" from the bottom of the body trim on the wheel well to the top of the 15" wheel. I thought I read somewhere that I should be able to see the top of the tire when looking at the side of the trailer. I guess I read it wrong.

Do you have any idea if its ok to run a truck Radial tire?

Thanks for the reply

Larry.

Clearances, is always the question.

You do not need to remove anything in order to check your axles.

Please refer to that article.

Andy

[Minnie's Mate]

I could not see the top of the tire treads when my Airstream came from the factory. I don't think you are supposed to be able to on any Airstream travel trailer, new or used. Andy can correct me if wrong. Go to Airstream Central and read the article he refers to. I'm assuming it is the same process he had posted on his website for Inland RV Center. If so, it is pretty straight forward and an easy process to do.

[Inland RV Center, In]

Originally Posted by Minnie's Mate

I could not see the top of the tire treads when my Airstream came from the factory. I don't think you are supposed to be able to on any Airstream travel trailer, new or used. Andy can correct me if wrong. Go to Airstream Central and read the article he refers to. I'm assuming it is the same process he had posted on his website for Inland RV Center. If so, it is pretty straight forward and an easy process to do.

I have no idea where the "myth" started that you must see the top of the tire treads, when checking out a torsion axle.

The correct observation is that you should be able to see 2 to 3 inches of the tire, "above the top of the wheel".

That's a long way away from the top of the tire.

As the rubber rods age, the amount of the tire that can be seen above the top of the wheel, will slowly dimimish. When you can no longer see the top of the wheel, however slight, further check ming of the axle would be in order.

Generally speaking, when the very top of the wheel is hidden, more than likely the rubber rods have exhausted their life.

The only other test, is raising one side of the trailer. The tire/tires should appreciably drop, about 2 to 3 inches. That syas the rubber rods are still alive.

If a small or no drop of the tire/tires happens, then that indicates that the rubber rods have solidified, rendering them useless. In turn, the hard rubber rods will allow considerably road shock to be directly transfered to the chassis and shell, leading to many things just falling apart.

Andy

[2airishuman]

Originally Posted by larry b

...would this work or is it asking for trouble?

no offense larry but before buying new wheels and tires that are NOT the original size...

U need to do more homework.

it's ALL been posted and all available to read and clearly U can do whatever U want...

but

-the ST vs LT issue is part of this,
-the 15 vs 16 is part of this...
-ONE PLUS sizing vs keeping the original circle size (with 16s) is part of this...
-clearance is part of this (width and diameter)...
-axles/brakes/hubs may be part of this...
-load rating of ST tires vs LT tires is part of this (they aren't the same)
-tire brands/models is part of this...

and so on.
_________

IF u are a total noob' to the tire thing especially as related to trailers, it is wise to READ READ READ...

then ask a few questions...

then stick with the STOCK SIZE and use ST tires...

unless u like blindly buying stuff that may or may NOT work out...

cheers
2air'

[ROBERT CROSS]

Larry,

What percieved advantages do you see in 235/80/16 LT tire?

IMO...upgrade stock size st tire and install centramatics.

Stream Safe...