Trailer wheel balancing question.

[DJK555]

I have a new to me 2009 Komfort TT, 24', towed by a '13 F150 Ecoboost. The trailer has original tires mounted on factory upgrade aluminum wheels. I have put on approx. 3500KM. During the last trip I started getting a vibration starting at 80 KPH and continuing to 100 KPH. It noticeably smooths out after 100. This seems to be a wheel balance issue. To narrow it down I unhitched the trailer and drove the truck without any other changes. Vibration was gone. So...it seems like it is the trailer. I understand that there are varying opinions on trailer tire balancing. Mine have not been balanced. My questions are; Can a tire vibration on a trailer be felt in the tow vehicle?, and Does anyone have experience with the Dyna Beads product? Thanks in advance.
David

[TheGatherer]

I use #7 steel birdshot to balance my truck and trailer tires.. I tried the beads, but had a problem with a tire and the beads were too costly to keep buying.. so, the steel shot can be recovered with a magnet and do the job just as well for a fraction of the costs... steel shot don't damage the inside of the tire...use the same amount/weight as the beads...

[GoldWingRyder]

From Etrailer

Tire Balancing

At etrailer.com, our tire and wheel combinations are mounted so that the high heavy spot on the tire is aligned with the low light spot on the wheel. This provides adequate balance for trailer tires.

If you buy new tires for a set of rims, you can have them balanced. If you do balance trailer tires, remember that many trailer wheels are centered by the position of the lug bolts (these wheels are lug-centric) and not the center bore of the wheel. To get the best tire balance for lug-centric wheels, you should have them balanced using a pin plate adapter. This mimics the way a lug-centric wheel is mounted to a hub.

[kraazy3]

I have been told that new campers are fitted with cheap bias ply tires and are not balanced from the factory. My tires were worn unevenly so I bought new radial tires and had them balanced. So far they are looking good and I am sure they dont shake or vibrate. If I ever ordered a travel trailer I would make sure it came with balanced radial tires. Even if you put new tires on yourself the cost to do so is well worth it. If I remember correctly it was less than 60 dollars a tire mounted and balanced.---Be sure to protect your new tires from the sun with tire covers.
Ron C

[Lynnmor]

TexasChaps wrote:

Lynnmor wrote:
I once bought 4 new tire/wheel assemblies for my snowmobile trailer. Even after balancing, the square tires were so bad that they shook the truck. I returned them and bought a different brand of China bombs (only Chinese tires in that size) and that solved the problem.

Finally we have one other person on this forum that understands that trailer hubs and drums are not balanced. Balancing only the tire and wheel is only a feel good exercise, and you may still have a balance issue. I balance the assemblies and have been doing that for many years.

This very reason is why I use beads in my tires, they will balance not only the tire but all the rotating mass..

I have had brake drums that took 5.5 oz. to bring them into balance. When mounting a 4 oz. out of balance tire to that drum, it would require 1.5 oz. to 9.5 oz. to bring the assembly into balance, depending how they are oriented. How many oz. of beads would I add?

I find the heavy spot of the drum and the heavy spot of the wheel/tire and then mount them opposite, then balance the assembly.

[JIMNLIN]

DJK555 wrote:
Thanks for all of the great suggestions and also for the related discussion. To all of you that suggested that I may have a tire structure problem rather than a balance issue - you were correct! I had my local tire store take off the tires and the attached pic is what was found. Probably good that I didn't try to get one more trip out of them even though there was more than 50% tread remaining. I will now adhere to the replace them by time instead of wear approach.

Good catch.
Quality tires go a long way toward not having this happen again.

[TexasChaps]

Lynnmor wrote:
I once bought 4 new tire/wheel assemblies for my snowmobile trailer. Even after balancing, the square tires were so bad that they shook the truck. I returned them and bought a different brand of China bombs (only Chinese tires in that size) and that solved the problem.

Finally we have one other person on this forum that understands that trailer hubs and drums are not balanced. Balancing only the tire and wheel is only a feel good exercise, and you may still have a balance issue. I balance the assemblies and have been doing that for many years.

This very reason is why I use beads in my tires, they will balance not only the tire but all the rotating mass..

[ktmrfs]

Bird Freak wrote:
I have never understood why some do not balance trailer tires. Do you feel a tire out of balance on your car or truck? Why would you want your trailer to take the same beating from out of balance tires ?

x2. and I've had friend that didn't have tire balanced and complained about things moving around. Once balanced they commented how well things stay in place!!

and it keeps the tires from beating themselves to death as well.

good tire shops will know the stamped steel wheels are lug centric and use the correct adapter. Likewise on aluminum wheels that are used on trailers and they will use an adapter.

Although I suspect that a hub centric wheel is also very close to lug centric as well, or they wouldn't fit onto a hub and the studs. Other way around is not necessarily true. A lug centric wheel could have the hub hole way off center since it doesn't align to anything.

you will still have some out of balance since the brake drums aren't balanced AFAIK, since I've never seen a weight on them like a car brake drum has to balance it. But that out of balance is much shorter radius so the effect is not near as noticeable.

another reason for balancing is that if the tire is way out of round you'll see it when balancing (or twisted belts etc.) at which point I decline the tire and say try another one.

[DJK555]

Thanks for all of the great suggestions and also for the related discussion. To all of you that suggested that I may have a tire structure problem rather than a balance issue - you were correct! I had my local tire store take off the tires and the attached pic is what was found. Probably good that I didn't try to get one more trip out of them even though there was more than 50% tread remaining. I will now adhere to the replace them by time instead of wear approach.

[JIMNLIN]

"Never had them balanced." Is it only a problem when you can feel it in the truck? By running unbalanced tires over a long period do you suppose that could have been part of the cracked centers, loose lugs, etc. that you referred to?

No....for several reasons.
Your incorrectly assuming because the tires on a trailer weren't balanced on a machine they cause vibrations on the trailer.
The biggest reason tires on a loaded trailer (rv or non rv) don't show out of balance wear patterns like a truck tire is those short 26" long very stiff non progressive leaf springs on a trailer vs a 70-76" long soft riding progressive leaf springs on our trucks.
Lugs on trailers become loose more from side scrub stresses.

Cracked centers are not caused by a out of balanced tires on a trailer....but rather side scrub forces from backing or sliding around corners on close spaced axles on our trailers.

All trailers can have shaking just from rolling down the road due to road imperfections/rr track crossings/etc causing Loose screws/open doors/loose molding/popped fasteners/etc and all can happen with balanced tires according to those that have their tires balanced and had those issues.

As has been brought up many times before in trailer tire balance discussions is that trailer hubs are not machined balanced as automotive hubs on our tow vehicles.

If someone has a tire jumping up and down on a loaded or unloaded flatbed trailer or a RV trailer then its time to get the defective tire off the trailer

[aftermath]

JIMNLIN wrote:
I've bought and worn out dozens of tires on trailers and have never had them balanced.
Now I have felt viberation at times especially when those tires on the trailers usually has 40k-50k miles. A simple visual inspection showed the tread belts were split and separating.

Time to find out why the tires are suddenly causing vibrations.

And also I've had wheel issues also causing vibrations such as split tire bead seat on the rim and cracked centers/loose lugs/etc.

"Never had them balanced." Is it only a problem when you can feel it in the truck? By running unbalanced tires over a long period do you suppose that could have been part of the cracked centers, loose lugs, etc. that you referred to?

Some facts here. An unbalanced tire will produce vibration while going down the road. Vibrations will be transferred to the vehicle.

Lets not get into a discussion of a truck vs a trailer and how much vibration will be felt, vibration is vibration, degree not withstanding. Vibration over time will create some serious issues. How many threads do we read about people unhappy with their trailers when screws come loose "for no reason", cabinet doors don't close like they should, moldings start to separate, plumbing connections start to leak and on and on?

I own an Airstream and the design creates special concerns for us. Shaking an Airstream will result in popped rivets, loose screws, open drawers to name a few problems. The skin is connected to the frame and acts like a unified body. Shake the wheels, you shake the entire trailer.

It is imperative to reduce, or remove, shaking of the trailer. Balancing tires is not a perfect solution and that is why many use centramatics and those bead balancers after balancing their tires. While balancing tires is not perfect it is a good place to start and the cost is relatively small when compared to the cost of damages caused. After I took possession of my slightly used trailer I noticed drawers open after we got to our destination and a few popped rivets. I replaced the tires, made sure they were balanced and all those issues went away. You certainly don't have to balance your tires but it doesn't hurt. I guess if you can't feel it shaking then it must be just fine.

[RCMAN46]

A tire shop worth its salt will have adapters to lug-centric balance tires.

I can not believe a tire that is bouncing up and down as I have seen on many trailers will not put excessive stress and wear on the suspension.

Even on this Forum I have seen pictures of shackle plates that have oval shaped holes and I suspect it was mainly due to an unbalanced tire.

Why don't trailer manufacturer's balance tires. Simple $$$$$

[LarryJM]

SoCalDesertRider wrote:
Modern acorn style lug-centric wheels are indeed self-centering, due to the conical shape of the lug nuts and conical shoulder of the lug holes in the wheel.

The least self-centering of any wheel are those old style aluminum and magnesium wheels that used the mag wheel style, squared shoulder holes and long shank nuts with washers under the nut shoulder. I still have an old set of American Racing Outlaw aluminum wheels in 16.5 size with square shoulder holes and all the washer style nuts to go with them. They're probably from the 1970's or early 80's.

While a tad off topic FWIW for the last 30 years or so even all the automotive type vehicles have used the hub centering method even if they had the what is properly called the conical fastening system. From my understanding in talking to an actual design engineer for wheels for auto manufacturers this system was mainly used in that it was more user friendly for the torque range for proper clamping force on wheels. No auto manufacturer used what is often called "lug centric" wheels as OEM and that term is used for the most part by aftermarket manufacturers. Another more important reason is that it is a manufacturing "NIGHTMARE" in trying to machine a hub and then a wheel that matches based on those multiple lug positions. You can get the tolerances if you manufacture it with a center tolerance. This is also a great reason for torquing trailer wheels in many stages with the proper sequence with the first two to three torques being "finger tight" then around 15lbs-ft and then 30lbs-ft. This gets you as close a possible to the most centered wheel on the hub you can do for a true "lug centric" system.

As a side note Dexter did produce a hub centered wheel system that was called the "Dexter Star" back in the 70's and maybe into the 80's. Not sure about their other wheel types since up until 2004 Dexter did manufacture wheels for their axles, but that is no longer the case.

Larry

[SoCalDesertRid1]

Modern acorn style lug-centric wheels are indeed self-centering, due to the conical shape of the lug nuts and conical shoulder of the lug holes in the wheel.

The least self-centering of any wheel are those old style aluminum and magnesium wheels that used the mag wheel style, squared shoulder holes and long shank nuts with washers under the nut shoulder. I still have an old set of American Racing Outlaw aluminum wheels in 16.5 size with square shoulder holes and all the washer style nuts to go with them. They're probably from the 1970's or early 80's.

[LarryJM]

richardgarneau wrote:
answer I got from tredit tires : The other part about balancing is that these wheels are lug-centric and not hub-centric. That is, the wheel is centered and balanced based off the torque of the lugs on the axle, unlike automotive where it is centered by the hub bore and held in the middle. This allows for changes in balances and makes it difficult to zero in on a balance. Also, many other styles of trailers are now going to aluminum wheels, so there are landscape trailers, utility trailers, cargo trailers, etc. . . that consistently have different loads that will cause wear and tear on tires that a balance isn’t going to change. Many assume balancing will even out any vibrations, but again most of these problems stem from uneven loads.

Excellent point and something I knew about, but forgot to include in my initial response.

Hmmmm there is a reason you don't find many if any at all TT tires balanced from the factory to start with.

Larry