The Long Tow: Thought about tires lately?

colin_koehler

colin_koehler

Great SCOTT!
Ok, Y'all have been towing longer than I have but I obsess about things. When I began towing I noticed the difference between trailer tires and normal tires: Trailer tires max PSI are listed for COLD inflation, however normal tires are not.

So with the tires on my Van rated at Max load @ 51 psi I set them at 44psi and check them again about 75-100 miles into the trip depending on how hot the day/pavement is and adjust as necessary. As for the trailer: If the side of the tire says 50psi COLD, I set them at 50 PSI COLD and leave them.

In doing my research I've found the 2 most common reasons for trailer tire failure is UNDER inflation and age.

Good info from Goodyear on trailer tires:

http://www.goodyear.com/rv/pdf/marathon_gen_info_032806.pdf

· Industry standards dictate that tires with the ST designation are speed restricted to 65 MPH under normal
inflation and load conditions unless a different speed restriction is indicated on the sidewall of the tire.

· Based on industry standards, if tires with the ST designation are used at speeds between 66 and 75 mph, it is necessary to increase the cold inflation pressures by 10 psi above the recommended pressure for the load.


---Do not exceed the maximum pressure for the wheel.
---If the maximum pressure for the wheel prohibits the increase of air pressure, then the
maximum speed must be restricted to 65 mph.
---The cold inflation pressure must not exceed 10 psi beyond the inflation specified for the
maximum load of the tire.
Click to expand...

Have a safe and uneventful trip out to Spokane everyone!
 
...I think that inflation pressure for passenger car tires are also measured cold. 'hot' is just too big a variable for your average dipstick to figure out.
I also inflate my ST tires to the maximum permitted for the tire, cold, and leave them there.
The only 2 downsides are increased harshness for the trailer (who cares? it has springs!)
and possible reduced wear. As the tires will age out FAR before they even show much wear, again, who cares?

Haven't had a tire problem yet... except maybe that I won't be towing my trailer to Spokanistan again this year...

t
 
colin_koehler said:
In doing my research I've found the 2 most common reasons for trailer tire failure is UNDER inflation and age.
Click to expand...

I think you left out the most common reason: Made in China. Overall, Chinese tires do not have a good history.
My now 6 year old -- yes, end of life for trailer tires -- original equipment tires had a failure while sitting still at PIR. Thankfully it did die while just sitting. The cause on my always correctly inflated Chinese tires was tread separation.
I think a good way to check your trailer tires before a tow is to jack up the axle and spin the tire, looking for out of round. Alternatively you can run your gloved hand over each tire feeling for bumps.

Another point to ponder is when one tire fails.
If you are at max capacity on a two axle trailer and one tire fails, the manufactures recommend you replace the still inflated tire on that same side.
Why?
You have just overloaded the crap out of the still inflated tire on the side that failed.

colin_koehler said:
Based on industry standards, if tires with the ST designation are used at speeds between 66 and 75 mph, it is necessary to increase the cold inflation pressures by 10 psi above the recommended pressure for the load.
Click to expand...

When you tow with an RV anything above 60MPH just makes fuel economy miserable. Oh wait, it's already miserable.
 
What's funny Bill is that I see on a lot of forums that many people are not a fan of Carlisle tires but they are made in the USA.

It also appears that the most common enemy of trailer tires... UV light (OMG they're like Hoosiers, quick cover them up before the sun RUINS THEM!).

Some say, that if you leave your RV/Trailer/Camper sitting for extended periods you should cover up the wheels.
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colin_koehler said:
Some say, that if you leave your RV/Trailer/Camper sitting for extended periods you should cover up the wheels.
Click to expand...

Now you're even starting to sound like the Stig.

If you live in a sunbelt state, which has higher UV than here, that may be a concern.
When I bought my RV (from SoCal) it had tires well over 10 years old and they were heavily cracked. They looked very unsafe.
Around here I think our tires rust out first.

Some say, any tires over 6 years old should be replaced, regardless of how they look.
When my tires get to be 6 years old I just look at them more often.

It does take some time to check all 10 tires on the RV and the trailer, but I use my air tank (if needed) and check before every trip. I was really bad about checking before I left the track for the trek home, but my last failure has me rethinking that!
 
I recently trailered a car across the country (3050 miles!). I had to replace the two front axle trailer tires early on in the trip due to one tire having a chunk of tread separating from it and the other having two punctures but still holding air. Both tires were 4 years old. Luckily, I had a spare tire and was able to get to a Les Schwab tire store and have the two bad tires replaced on the spot.
 
A quick, smooth application of trailer brakes would have helped there.

I've never had the death wobble, but having a long wheelbase tow vehicle that outweighs the trailer helps.
 
Coming back from Spokane last year the wife and I decided to spend the night at a local RV spot and have a nice leisurely drive back the next day.
The idea was sound -- the wind the next day was not.
In a 24' RV with a 24' enclosed we are just a rolling billboard.
When 70 mph gusts hit you sideways the term 'death grip' on the wheel becomes real.
The trip over the bridge was very difficult at 30 mph.

Although it was capable of towing with a simple hitch, this episode guaranteed I would buy a load leveling hitch with built in anti-sway system.
I can still feel 18 wheelers zooming by, but it no longer does an automatic lane change.
I can also change radio stations now.
Before I had to have two hands on the wheel at all times.
Now I can actually take one off and hit the search button!
 
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