GYMs from China or not?

[Tireman9]

Originally Posted by Jacob D

The "horror stories" are just that.....stories. I run nothing but Good Year tires on my TV and vintage AS. I once ran a set of Canadian made GYM's for 13 years with only one flat because of a nail. That'w what woke me to the age of the tires and I replaced them with a set of China tires which have been on for two years with no issues. I run them with 43 psi pressure on a tandem axle trailer which is the pressure indicated for the weight of my trailer on the Good Year chart.

You can buy spray treatment to prevent UV degradation and cracking which some folks call "dry rot".. I spray mine once a month with Armor All Tire Foam and keep them covered if idle for more than a month. Storage in my drive way is on pavement which I think helps. To find out the correct pressure to use, weigh your trailer one axle at a time and consult the manufacturer's weight chart. Better yet, weigh one wheel at a time and use the pressure indicated for the highest weight on all wheels.

RE "pavement" be sure that is not asphalt as the oil in the tar can attack the rubber.

Covering tires especially with white covers is a good idea as it lowers the tire temperature significantly which slows the aging (dry-rot) process. See my blog post of June 16, 2011 "Tire Covers - Do they do any good?" for test data.

Trailers are not the same as on motorized units (Motorhomes) as the tires of a trailer do not rotate about the center of a turn radius but are dragged around every corner and turn. This results is a significant increase in "Interply Shear" which is the force in the tire structure that is trying to tear the tread off the body of the tire. You can learn about more with Google of "Interply Shear Tires"
To lower this force trailers should always run the max inflation shown on the tire sidewall.

You still should get the TT weighed to be sure you are not overloading your tires as a majority of RVs have a tire and/or axle in overload when checked.

[Tireman9]

[QUOTE=richw46;1774755]

Originally Posted by tjdonahoe

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The only problem I've had so far was a GYM on my boat trailer, it blew out when I was going 75 on a 95 degree day and the tire was about 12 years old, maybe more. It was not a Chinese made tire but the new ones are.

snip

Until late 2015 all ST type tires had a MAX speed rating of 65 mph. That is not an average. Think of it like the engine redline. You can run an engine bast that speed but not without suffering consequences.

Max speed recommendations in print from some tire companies for any tire in RV application is 75 no matter what the tire says. RV application is much tougher than car application due to constant high load.
With data showing that a majority of RVs are operating with one or more tire/axle in overload and the side loading placed on TT application I would stick with 65 as a MAX no matter what the tire says. That is what I do as a tire engineer w/40 years experience. Never had a "blowout" or tire failure while running down the road.including on RVs or 1Ton dually w/26' enclosed trailer with Camaro race car inside going cross country.

[Tireman9]

Originally Posted by richw46

I've read that passenger tires on a trailer is not recommended because passenger tire sidewalls are soft for a smoother ride. They don't provide the lateral support to prevent swaying/fishtailing. It may not be an issue on your motorcycle trailer but I wouldn't put them on my AS or boat trailer.

It isn't the color of the trailer or even what you are hauling. It is the combination of speed load and inflation that if controlled can result in no failures or many failures.

[tjdonahoe]

Originally Posted by richw46

I've read that passenger tires on a trailer is not recommended because passenger tire sidewalls are soft for a smoother ride. They don't provide the lateral support to prevent swaying/fishtailing. It may not be an issue on your motorcycle trailer but I wouldn't put them on my AS or boat trailer.

My 1973 23' avion came with G 78/15, latter years they were 225/75/15 and they did fine, owned her 28 years and no tire trouble.....

[Rich W]

[QUOTE=Tireman9;1776158]

Originally Posted by richw46

Until late 2015 all ST type tires had a MAX speed rating of 65 mph. That is not an average. Think of it like the engine redline. You can run an engine bast that speed but not without suffering consequences.

I'm smarter now. That was before I joined this forum and learned about a 65 max speed on the ST tires. I keep 60-65 when pulling the AS. The Goodyear site says I can increase the max pressure 10 lbs. go 70 MPH, so that's what I've been doing and no problems. In the off season I put the boat trailer up on jack stands. The AS is parked on concrete but I still have wood slats under each tire. If I'm not using the AS I still don't let it sit more than 2 months before taking it on a round trip from the storage lot to my house and back, 23 miles each way. Warms up the tires and avoids flat spots.

[damonbeals]

Go to Tirerack.com and look up the tire your interested in, and it will tell you the country of origin in the specs. Tirerack is the only online retailer I have found that lists this.

Damon
#4827

[dannydimitt]

Originally Posted by dannydimitt

Have been running car tires on trailers since the sixtys , we ran P235/75R15 inch Generals on our 66 Airstream , and ran Cooper P235/75R15s on the 2005 Airstream for years including an 11,000 mile trip to Alaska and back . Have replaced them with the same size p rated Michelins 2 years back .
There is defiantly no problem whatsoever in the handling of these trailers and the shocks that are absorbed instead of being transferred to the trailer makes for a much smoother ride.

I neglected to mention that the 11,000 mile trip to Alaska and back with the Cooper Trendsetter car tires on the 2005 Airstream was accomplished with no weight distributing hitch at all . Just the ball and a single sway control bar with light pressure applied .

[Rich W]

A few people have posted that they have run with passenger tires on their trailers for years and never had a problem. All I can say is that it's not recommended because of their construction. Sidewalls on a passenger tire are thinner for a better ride and the tread design is for traction. Trailer tires have thicker sidewalls for better control and a tread design for less resistance to rolling instead of traction.

My AS follows my TV very well, never had an instance of sway, with cross winds or trucks passing me, even one after the other. On our way home from Texas last month I had signaled to change to the right lane, started my move and a car that was behind me gunned it and began passing on the right. Just reacting to his maneuver I pulled hard to the left to stop the lane change and that's the first time I felt anything close to sway. It came back right away, no problem but I am glad to have the ST tires.

If you've been running passenger tires on an AS maybe you've been lucky and never encountered an emergency situation. There are lots of risk takers in the world, I'm not one of them. I don't see the point in using a tire that is not designed for a vehicle application, particularly if the tire industry says it's not safe.

My family is too precious to me and there is enough risk just being on the road. I'm playing it safe. Your mileage may vary.