Pulling my first camper and recognizing problems with "sway"

carl.swoyer

Well-known member
Another couple of questions ,
What type of tires are on the truck and trailer? Passenger rated tires or truck rated tires.
Also are you setting the tire pressure to the max cold rating or the minimum?
Setting the pressure to the max cold rating would provide more sidewall strength.

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biddysere

Member
Carl. If you are asking me - I am running 10 ply on the truck and factory tires on the camper. It actually felt better with the Stock GMC tires running 36#.
10 ply seems like it runs the ruts more
 

marknewbill

Well-known member
Update:
Sorry its been a little while while I try to sort this out.

I did a few things:

I bought a scale and weighed my tongue and then all wheels as well. I show 6300 pounds on the wheels and 1000 pounds on the tongue. My scale may not be perfectly accurate, but should be close enough to judge percent. that is 14 percent on the tongue after all I have done, and loaded as traveling other than food and a few clothes. the food goes over the axles in the fridge so that wouldn't change much, and we only bring a few clothes at a time.

I added a second sway bar. that didn't seem to help anything.

Next, I removed the rack on the rear bumper and spare tire, and relocated the spare under the bed. that probably gave me another hundred pounds to give the 1000 pound tongue weight. I didnt use the rack anyway.

I also read somewhere your truck tires play a big role, and on another forum it was mentioned certain Wrangler tires are not suitable for trailer towing as they cause sway since the sidewalls are not steady. I don't have that exact tire mentioned, but I do have the Wrangler fortitude tire. To make the best of it I did raise the pressure in all 4 truck tires to 50 PSI, just shy of the max cold pressure. I figured this was good since with a 1000 pound tongue weight and about 300 pounds in the bed along with 2 passengers, we are looking at the full payload of the 2019 F150.

I will consider if I should buy LT tires next time and see how those work?

I gave it a go and it was so much better with more air pressure and perhaps shifting about 100 pounds more to the front by removing the rack.
It is still not absolutely perfect, as with a little wind it is still a little unsteady, but at least it is not constantly moving the truck around on the last trip and I actually could get up to 70 mph this time on the interstate with no constant side to side. I am not sure if the weight was the thing (as it was always within 12 percent before moving the tire and rack), or the tire pressure, but between both it made a noticeable improvement.

Mark Newbill
RE275
2019 F150
 

mlpeloquin

Well-known member
Speed is not your friend. A good gust could get you oscillating and flip the trailer and you. This would take seconds to happen. Your trailer tires are rated for what speed? Back off that maximum speed and be safe. You have not fully solved your problem. There are plenty of examples on U-Tube of speed and sway happening with side wind gust flipping trailers and trucks. Bumper trailers should be towed at 60 mph for safety. Have you measured the distance from the hitch ball to the rear trailer axle and the hitch ball to the entire length? It should be no less than 57%, otherwise it is inherently unstable. Yes manufactures do make inherently unstable trailers by the position of the axles. The distance from the tow vehicle’s rear axle to the hitch ball can contribute to sway. Less distance is always better. Ideally a longer wheelbase vehicle with a shorter overhang from the rear axle to the hitch ball is best. It is associated with the lever effect. The distance between the rear axle and the hitch ball position can be understood as the lever length. The longer the distance it is the higher the lateral forces applied to the axle position the more it wants to sway. And yes I have studied and am repeating what I have learned form several web pages.
 

marknewbill

Well-known member
Speed is not your friend. A good gust could get you oscillating and flip the trailer and you. This would take seconds to happen. Your trailer tires are rated for what speed? Back off that maximum speed and be safe. You have not fully solved your problem. There are plenty of examples on U-Tube of speed and sway happening with side wind gust flipping trailers and trucks. Bumper trailers should be towed at 60 mph for safety. Have you measured the distance from the hitch ball to the rear trailer axle and the hitch ball to the entire length? It should be no less than 57%, otherwise it is inherently unstable. Yes manufactures do make inherently unstable trailers by the position of the axles. The distance from the tow vehicle’s rear axle to the hitch ball can contribute to sway. Less distance is always better. Ideally a longer wheelbase vehicle with a shorter overhang from the rear axle to the hitch ball is best. It is associated with the lever effect. The distance between the rear axle and the hitch ball position can be understood as the lever length. The longer the distance it is the higher the lateral forces applied to the axle position the more it wants to sway. And yes I have studied and am repeating what I have learned form several web pages.


Hi. Speaking of speed. How would one know the max speed when they never talk about that on any stickers or in the owners manual. Are you saying the typical travel trailer should not be pulled over 60 mph? From a victim of getting rear ended on the interstate that seems hazardous to go so slow?
 

JohnDar

Prolifically Gabby Member
Hi. Speaking of speed. How would one know the max speed when they never talk about that on any stickers or in the owners manual. Are you saying the typical travel trailer should not be pulled over 60 mph? From a victim of getting rear ended on the interstate that seems hazardous to go so slow?

Doesn’t take a degree in rocket science to feel when you’re too fast. You’ll feel it in the steering wheel and your butt as the trailer starts to oscillate. Even with a properly set up heavy 5th wheel and 8000 lb. dually pulling it, the rig will let you know. Top speed for me was 65, even though the trailer tires were rated higher.


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carl.swoyer

Well-known member
If the truck came with Wrangler tires they are most likely a passenger rated tire not intended for towing. It would be a good idea if that's the case to upgrade to an LT TRUCK TIRE.

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Flick

Well-known member
Hi. Speaking of speed. How would one know the max speed when they never talk about that on any stickers or in the owners manual. Are you saying the typical travel trailer should not be pulled over 60 mph? From a victim of getting rear ended on the interstate that seems hazardous to go so slow?

In most cases, traveling the “posted” speeds is the best option, whether trailering or not.
Traveling posted speeds and using common sense normally will be the safest.

With that being said, the road being traveled for example, a country FM or an interstate is a huge consideration. A country FM may not be safe at the posted 60 MPH under certain conditions but an interstate with traffic flowing may be safe at 70. Even if the interstate is posted higher than 70, I rarely travel faster than 70 unless it’s a safety factor.

Having a CDL since I was 16 years old and being in attendance at 100’s of safety meetings gives me an insight into some important info that some would consider very valuable.

Safe travels.
 

danemayer

Moderator
Staff member
Apart from handling/sway issues, 70 mph is too fast for most trailer tires.

Most trailer tires are rated for a maximum speed of 65 mph. The rating usually reflects the tire's ability to shed the heat that results from normal flex of a properly inflated tire. Traveling faster than the speed rating may cause a heat buildup that's damaging to internal tire fibers. Traveling at the rated speed with underinflated or overloaded tires causes excessive flex and a damaging heat buildup as well. Internal heat damage is cumulative and irreversible. So the consequences may show up as a blowout at some future date - even if driving slower when the blowout occurs.

Check your trailer tire speed rating at the manufacturer's website (not the tire dealer's website).
 

Flick

Well-known member
Apart from handling/sway issues, 70 mph is too fast for most trailer tires.

Most trailer tires are rated for a maximum speed of 65 mph. The rating usually reflects the tire's ability to shed the heat that results from normal flex of a properly inflated tire. Traveling faster than the speed rating may cause a heat buildup that's damaging to internal tire fibers. Traveling at the rated speed with underinflated or overloaded tires causes excessive flex and a damaging heat buildup as well. Internal heat damage is cumulative and irreversible. So the consequences may show up as a blowout at some future date - even if driving slower when the blowout occurs.

Check your trailer tire speed rating at the manufacturer's website (not the tire dealer's website).

After reading this, I did a little googling on, as an example, Goodyear tires. Some of their tires, like the Marathon are rated at 65mph. The Endurance, according to them, is rated at N or 87mph. The bulletin actually says on the Marathon to add 10psi for safer and higher highway speeds. The extra 10 psi does not increase your weight carrying ability but allows tires to run cooler. The G614 tires are R rated at 106mph.

The Sailuns I use are L rated at 75mph.

Also, while trailering at night, tires run cooler, hence the heat is not much of a factor.

I’m sure that if I look long enough, I could find info that contradicts what I found. But I had a little time sitting here in KEY WEST looking over the Gulf of Mexico thinking about the 1500 mile return trip home next week.
 

danemayer

Moderator
Staff member
After reading this, I did a little googling on, as an example, Goodyear tires. Some of their tires, like the Marathon are rated at 65mph. The Endurance, according to them, is rated at N or 87mph. The bulletin actually says on the Marathon to add 10psi for safer and higher highway speeds. The extra 10 psi does not increase your weight carrying ability but allows tires to run cooler. The G614 tires are R rated at 106mph.

The Sailuns I use are L rated at 75mph.

Also, while trailering at night, tires run cooler, hence the heat is not much of a factor.

I’m sure that if I look long enough, I could find info that contradicts what I found. But I had a little time sitting here in KEY WEST looking over the Gulf of Mexico thinking about the 1500 mile return trip home next week.

The Goodyear G614 is rated for 75MPH. Here's a link to the Goodyear spec sheet with that information.
 

marknewbill

Well-known member
Re: Pulling my first camper and recognizing problems with "sway"

If the truck came with Wrangler tires they are most likely a passenger rated tire not intended for towing. It would be a good idea if that's the case to upgrade to an LT TRUCK TIRE.

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I agree, I plan to do that soon.
I need to figure out for my 275 65 18 tires, what brand would be best for the LT?

- - - Updated - - -

After reading this, I did a little googling on, as an example, Goodyear tires. Some of their tires, like the Marathon are rated at 65mph. The Endurance, according to them, is rated at N or 87mph. The bulletin actually says on the Marathon to add 10psi for safer and higher highway speeds. The extra 10 psi does not increase your weight carrying ability but allows tires to run cooler. The G614 tires are R rated at 106mph.

The Sailuns I use are L rated at 75mph.

Also, while trailering at night, tires run cooler, hence the heat is not much of a factor.

I’m sure that if I look long enough, I could find info that contradicts what I found. But I had a little time sitting here in KEY WEST looking over the Gulf of Mexico thinking about the 1500 mile return trip home next week.


The "Trailer King RST" on the trailer are rated for 87mph. now I will never go that fast, but at least we know the tire is not the limiting factor.
Maybe I need a poll for a medium to large bumper pull how fast you normally drive on the interstate, when there is no apparent hazards, other than your speed. IE, what you feel safe with your trailer assuming no other people driving at the time.
 

rwdennis

Active Member
google your brand trailer tire to make sure its not a "china bomb" on my last new trailer i drove it from the rv store to the tire store( 7 miles) and changed the tires to goodyear endurance , they worked flawlessly .
 
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