Bias Ply to Radial's - a few (critical?) observations

[RinconVTR]

After 3 seasons, 12-15k miles, I replaced the OEM Trailmaster bias ply 205/75R14's with Carlisle Radial trail RH. No blowouts, but about 3" of the center tread was raised, leaving me to suspect they will not last much longer.

Please save the comments about my new tire choice, that's not what my post is about. Its about my observations.

First, the tread profile. A number of manufactures, bias play and radial brag about a rounded tread profile. I never gave this much thought in the past, but now I find myself asking, why in the world would I want this on a large TT? I want a flat profile with stiff sidewalls to eliminate lateral movement. Look at the difference between my spare and the new radial. Rounded makes zero sense to me, thus a reason I avoided a couple other radial options.




Then look at the height/diameter difference. (YES...they are the same size tire!)








Finally, a comment on balancing. I have never balanced trailer tires until today. And look at the weights it took to balance them! I will ALWAYS balance my trailer tires from now on. For a few bucks more, it just makes sense.

[JIMNLIN]

Here is a paste and copy from one RV.net member found about his tire/wheel issues but glad he educated himself on the topic.

Topic: Trailers Rims vs. Automotive Grade Rims
Posted By: Wolfboro2 on 12/09/11 09:33pm

Most of you already may know this , but I would like to share my” trailer wheel “ experience with you . What I learned thru the hard-knocks is that trailer wheels (rims used on 5th wheels, travel trailers , horse trailers and other trailers) are not manufactured to the same specification used for “automotive grade wheels” (motorhomes have automotive grade wheels). I learned this info from axle manufacturer Dexter Axle Co . while I was trying to pick up data why my tire catastrophically delaminated and why all my RV rims are wobbling ( all are hopelessly out of balance and out of round on balancing machine)and why all the brand new RV rims I purchased( from two different sources ) also all are bad and wobbling to a point that automotive tire installer are unable to do any balancing at all ( and auto tire installers never seen anything like this , since they do not normally work on trailer tires)

-I tried to replace my rims with automotive grade rims with same size, load bearing capacity and bolt pattern . It did not work out, countless hours of search showed that no automotive rim has the same “off-set value “ as RV trailer rim although they may have the same load cap. and bolt pattern( I never heard of offset value till then ) . I did not want to use rims with a different off-set value since I was worried about this might cause different force patterns acting on wheel bearings .

- Most RV’ers take their RV to an RV-dealer for tire replacement and most of them do not have a chance to see the action behind the scene (if the RV jacked up correctly or if the wheels are balanced or how bad the rims are on balancing machine). Since RV rims are exempt from stringent automotive standards ,they are not “true”, all are wobbling and balancing of trailer tires is not a generally accepted practice . I removed my RV trailer tires one-by –one and took them to 2 different automotive tire installers . Wheels were so badly wobbling that the store manager had to interfere with. I purchased brand new rims from 2 different trailer part suppliers. The tire installers actually showed me the rims on the balancing machine that they were all hopelessly out of round . I found it hard to believe and took the rims to a different automotive tire installer to verify. Yes , they were all wobbling as if they were bent . One of the RV rim supplier put it this way “these are for trailers and nobody cares ” , perhaps he meant horse-trailers, since they all have steel wheel-wells and it will not get damaged if a tire gets busted and delaminated partially .

-My personal thought is that when a rim has significant side-to-side motion (under heavy trailer weight) , the tire will be subjected to additional shear stresses as you roll down the highway (as if you you were doing fast do-nuts in a parking lot) . This may cause the delamination , perhaps I would not care much , If the partially delaminated tire do not cause enormous amount of damage in and around the tire well

-There is a trailer wheel manufacturer association , I sent them an e-mail asking why the industry insisting on using substandard wheel specification jeopardizing public safety and costing RV’ing community a lot of headacke . I did not receive any response .
(snipped for length)

[Bird_Freak]

RinconVTR wrote:

Huntindog wrote:

Doesn't do much in terms of what? IMO it can only improve things or wont be noticed. It sure wont make ANY condition worse! Actually it could make it worse if a lug plate wasn't used to do the balancing.
Most trailer rims are lug centric, not hub centric. This means that the center hole is not perfectly centered. Using a hub in the center hole to balance the tire will garauntee tat it is out of balance.. Quite possible worse than it was before. Tire shops if they even have lug plates hate to use them. It takes longer. Several times I have asked for lug plates to be used, and watched them NOT do it... One time they admitted they didn't have the right one. When I told them I wanted my money back,,, they got one from another location real quick.

So if you believe in balancing, make sure it is really balanced!:B

.

For steel wheels, you may have a point. Aluminum? Chances are extremely slim the hub was not machined concentric with the bolt pattern. Very slim.

Frankly, I'm surprised shops today even knew what a lug plate is
!

If you were trying to balance a wheel that the center hole was off center you would see the rim out of round when the balancer spins up. Dead give away.

[JJBIRISH]

Anything that spins can benefit from balancing…

The individual has to determine their own perception of a cost-benefit ratio…

Myself, on a trailer steel rim, I would check the rims balance and rims radial run out first… on my rims the center hole is centered with no appreciable difference between hub or lug mounting and they can be balanced by either hub or lug centric means…
the valve location is also the heavy balance point so I make sure the tires yellow dot (light spot) on the tire is positioned in line with the valve hole (heavy spot)…
For radial run-out I would ignore the tires yellow dot and use the tires red dot (high spot) on the tire, if it has a red dot… the rim may (should) have a dimple at the rims low spot for matching or lacking that again use the valve hole location…

There really is no down side to balancing a wheel other than the one time cost itself…
As far as balance goes you can’t make it worse using a properly balanced wheel… only mounting a unbalanced wheel on a unbalanced hub and drum has that risk of being worse by having the 2 heavy points closely aligned…

[RinconVTR]

Huntindog wrote:

Doesn't do much in terms of what? IMO it can only improve things or wont be noticed. It sure wont make ANY condition worse! Actually it could make it worse if a lug plate wasn't used to do the balancing.
Most trailer rims are lug centric, not hub centric. This means that the center hole is not perfectly centered. Using a hub in the center hole to balance the tire will garauntee tat it is out of balance.. Quite possible worse than it was before. Tire shops if they even have lug plates hate to use them. It takes longer. Several times I have asked for lug plates to be used, and watched them NOT do it... One time they admitted they didn't have the right one. When I told them I wanted my money back,,, they got one from another location real quick.

So if you believe in balancing, make sure it is really balanced!:B

.


For steel wheels, you may have a point. Aluminum? Chances are extremely slim the hub was not machined concentric with the bolt pattern. Very slim.

Frankly, I'm surprised shops today even knew what a lug plate is
!

[Huntindog]

RinconVTR wrote:

JIMNLIN wrote:


Tire balance.... not so much.
Mounting a balanced tire/wheel assy on a trailers hub that is not balanced doesn't do much.

Doesn't do much in terms of what? IMO it can only improve things or wont be noticed. It sure wont make ANY condition worse! Actually it could make it worse if a lug plate wasn't used to do the balancing.
Most trailer rims are lug centric, not hub centric. This means that the center hole is not perfectly centered. Using a hub in the center hole to balance the tire will garauntee tat it is out of balance.. Quite possible worse than it was before. Tire shops if they even have lug plates hate to use them. It takes longer. Several times I have asked for lug plates to be used, and watched them NOT do it... One time they admitted they didn't have the right one. When I told them I wanted my money back,,, they got one from another location real quick.

So if you believe in balancing, make sure it is really balanced!:B

More importantly, consider what is furthest from center and has the highest mass. The answer to both is the wheel and tire.

Sure, the drum and hub *might* not be balanced (I'm not convinced they are not) but being smaller, lighter, and much closer to center, I'm not concerned. Nor would this leave to believe I should not balance trailer tires at this point.

[JIMNLIN]

Lynnmor wrote:
Yes, balancing can make it worse or better. If the heavy spot of the tire and the drum were opposite each other, balancing will make it worse. If you never checked your drums for balance, you have no idea and shouldn't jump to conclusions.

Spec on.
Thats just one reason why spin balancing the assy while on the trailer works best unless the tire is egg shaped.
I'm surprised more folks didn't know this as its very common in vehicle racing where the rubber meets the road .......and even pulling trailers at lower highway speeds.
We also know a spring on a trailer is just 24"-27" long which acts as a huge damper for any out of balance situation .....unlike the soft coil spring on the truck or a 6' to 6 1/2' long rear springs on a truck. These tires need to be balanced.

Tire/wheel/suspension issue with a truck vs a trailer are apples vs oranges.

[RinconVTR]

Lynnmor wrote:

8iron wrote:
Do people balance their discs and/or drums on their tow vehicles?

They are balanced when made, trailer drums are not. .

Would please you provide a few links to prove this statement.

[RinconVTR]

Lynnmor wrote:

8iron wrote:
Do people balance their discs and/or drums on their tow vehicles?

They are balanced when made, trailer drums are not. Folks that never checked trailer drums for balance have no clue.

I think your missing the point, many times over. In short, worrying about balance of drums and hubs is pointless and no where near as critical as the wheel and tire.

My original point regarding balancing trailer tires when possible is that its only a few dollars more. In my case, only $2 per. So the question then becomes, WHY NOT? After doing so, you can clearly see how much weight was required to balance them, there would without a doubt be considerable vibes produced if not balanced. Would I ever know, probably not.

But think about all the items in your TT. We aren't hauling lawn mowers. I'm thinking of all the wood and glue, and hundreds of little screws. Seems like any vibration reduction we could do might help keep things "together" longer. (as if the roads aren't rough enough, but you get the point) I have no facts on this, and like I said, I never gave this a second thought, until now.

For an additional $8, I have 4 balanced wheels/tires on my TT. Why would I say no to this? Because for decades not many have felt the need? Well, may be the "need" isn't there, but it makes ZERO sense for me to decline getting them balanced for a couple bucks extra.

[Lynnmor]

8iron wrote:
Do people balance their discs and/or drums on their tow vehicles?

They are balanced when made, trailer drums are not. Folks that never checked trailer drums for balance have no clue.

[8iron]

Do people balance their discs and/or drums on their tow vehicles?

[Gdetrailer]

Lynnmor wrote:

Gdetrailer wrote:

Lynnmor wrote:
Yes, balancing can make it worse or better. If the heavy spot of the tire and the drum were opposite each other, balancing will make it worse. If you never checked your drums for balance, you have no idea and shouldn't jump to conclusions.

That depends..

The drum has a much smaller diameter AND MASS than the tire.

Car drums and rotors ARE "balanced", pretty easy to check to see if the drums have been balanced. Typically balancing on drums consists of the manufacturer either drilling /counter sinking into the heavy spot or adding a permanent weight (spot weld) to the light side.

Balancing drums on a trailer is not going to DRAMATICALLY change anything with the trailer due to the small diameter and MAS of the drum,

Balancing the tire on the other hand may or may not make any noticeable change since you are not RIDING in the trailer.

I have run trailer tires balanced AND unbalanced and FOUND NO DIFFERENCE in how the trailer tows or feels. How ever with that said, balancing CAN potentially add some life to the trailer tires since it will REDUCE the BOUNCING of the tires if they are far out of balance.

OK, I understand that you have never checked the balance of the assembly. So why comment?

I guess YOU don't have a clue about MASS and DIAMETER of said mass..

Why should YOU comment?

A drum is approx 10" in diameter and weighs about 25 lbs.

A tire mounted on a rim will weigh in 45 plus lbs, and the outer diameter will be 30 plus inches.

The MAJORITY of the tire mass IS ON THE TREAD.

Not to mention the outside diameter of the TIRE IS ROTATING at a much higher rate than the INSIDE diameter of the DRUM.

Rotation speed plus MASS makes a huge difference, not to mention the further out the imbalance the more pronounced the effect.

Balancing the drum has very little "effect" overall and balancing the TIRE CAN and will have more effect overall.

Simple basic high school physics class stuff.. Did YOU sleep through that class?

I suppose you balance your bearings and grease?

[6_7_tow_rig]

What am I missing here? I have had three trailers of which none have had "balanced" wheels and tires and have never had an issue or felt there was a problem. Is this a "fix" for a problem that doesn't really exist? What are people feeling? A vibration or something?

[Lynnmor]

Gdetrailer wrote:

Lynnmor wrote:
Yes, balancing can make it worse or better. If the heavy spot of the tire and the drum were opposite each other, balancing will make it worse. If you never checked your drums for balance, you have no idea and shouldn't jump to conclusions.

That depends..

The drum has a much smaller diameter AND MASS than the tire.

Car drums and rotors ARE "balanced", pretty easy to check to see if the drums have been balanced. Typically balancing on drums consists of the manufacturer either drilling /counter sinking into the heavy spot or adding a permanent weight (spot weld) to the light side.

Balancing drums on a trailer is not going to DRAMATICALLY change anything with the trailer due to the small diameter and MAS of the drum,

Balancing the tire on the other hand may or may not make any noticeable change since you are not RIDING in the trailer.

I have run trailer tires balanced AND unbalanced and FOUND NO DIFFERENCE in how the trailer tows or feels. How ever with that said, balancing CAN potentially add some life to the trailer tires since it will REDUCE the BOUNCING of the tires if they are far out of balance.

OK, I understand that you have never checked the balance of the assembly. So why comment?

[Gdetrailer]

Lynnmor wrote:
Yes, balancing can make it worse or better. If the heavy spot of the tire and the drum were opposite each other, balancing will make it worse. If you never checked your drums for balance, you have no idea and shouldn't jump to conclusions.

That depends..

The drum has a much smaller diameter AND MASS than the tire.

Car drums and rotors ARE "balanced", pretty easy to check to see if the drums have been balanced. Typically balancing on drums consists of the manufacturer either drilling /counter sinking into the heavy spot or adding a permanent weight (spot weld) to the light side.

Balancing drums on a trailer is not going to DRAMATICALLY change anything with the trailer due to the small diameter and MAS of the drum,

Balancing the tire on the other hand may or may not make any noticeable change since you are not RIDING in the trailer.

I have run trailer tires balanced AND unbalanced and FOUND NO DIFFERENCE in how the trailer tows or feels. How ever with that said, balancing CAN potentially add some life to the trailer tires since it will REDUCE the BOUNCING of the tires if they are far out of balance.