Tongue weight

Kayteg1 wrote:
Pay attention to semitrailers. Some of them have rear axles several ft apart.
When truck makes sharp turn, one axle goes perfectly sideways, regardless only 2 axles.
That the price you have to pay having non-steering tandem axles.
For my low boy trailer, the issue was that nobody was making quality tires in the size. I was buying them cheap, but then they did not last.
Sure would be easier do what semitrucks do, spend $600 per tire, but run 1/2 million miles on it.
Bottom line, triple axle trailer is not best for turns, but very good for anti-sway.

I drove an 11 axle steel truck for years, 163,000 gross. A bit more than you haul around... Actually, about 104,000 payload depending on the truck, engine and fuel capacity.

With an 11 axle, (8 axle trailer), 3 axle tractor, all axles are on air and on the trailer, the rearmost axles (2) lifts as well as the front 3 to mitigate tire scrub as much as possible. On a multi-axle spread trailer, the front axles are steerable and the back lifts.

With 3 down turning, one of the axles will scrub depending on how the trailer is loaded or the road is crowned, plus, its hard on the suspension because the suspension (and trailer frame) has to absorb the twisting stress. I own a tandem axle gooseneck with duals on each and oil filled axles. Much better tire wise to deal with and with a close tandem you can haul as much (if not more) than any pickup truck can pull. I've put 40,000 pounds on my gooseneck before and went down the road. Not fast, but I went. 20, 2000 pound round bales of hay is quite a load.

Pay attention to semitrailers. Some of them have rear axles several ft apart.
When truck makes sharp turn, one axle goes perfectly sideways, regardless only 2 axles.
That the price you have to pay having non-steering tandem axles.
For my low boy trailer, the issue was that nobody was making quality tires in the size. I was buying them cheap, but then they did not last.
Sure would be easier do what semitrucks do, spend $600 per tire, but run 1/2 million miles on it.
Bottom line, triple axle trailer is not best for turns, but very good for anti-sway.

Kayteg1 wrote:
I did tow 18k equipement trailer with triple axle.
Pintle hook not giving any stability, yet no sway issue, unless I loaded 12,000 lb bulldozer with blade facing front.
For some reason the air flow did make the difference.

I would never pull a tri-axle trailer when the axles are on springs, unless I had a discount tire card for rubber. Tri-axle trailers are notorious for wearing out tires quickly. Always scrubbing tires when turning.

No, on air with a rear axle dump, different story.

It is all about the flex - just like with dualy trucks.
Double wheels cut the flex by 1/2 if not more as this is not linear function.
US build trailers are build with very loose suspensions, so flex is huge.
That is why European vehicles have their tow capacity cut to 1/4 what they can do with European trailers.
Any sedan can tow 5000lb of European trailer, but those trailers do have totally different build and no problem to have less than 200lb tongue weight.
See the axle placed about 1/2 length of the bed? The driver claims to reach 120 kph on occasions. You will never see it on US build trailer.

I have wondered the same thing. Kinda like with tandem axles there is more weight spread over the axles vs. the tongue. It seems a tandem would be easier to balance without being hooked up than a single. I've balanced my single axle 6x14 but not for long!
Maybe put a different way...is the pivot point moved with tandems?
I think I understand your question, but pretty sure I didn't answer it.
edit add....wonder how hard it would be to move your single axle forward a bit?

Maybe you need to run a light duty WDH?

The recommendation is generally to put 10% or more on the tongue, and I've never heard that this should vary based on the number of axles. If you cannot adjust the load, can you move the axle?

When shopping for new trailer, pay attention at what distance from front the rear axle is placed.
Trailers are build with no shocks and usually their suspension have lot of side flex.
That adds to sway problem. Torsion axles are much better in this department.
So to avoid liability, trailer builders place the axle as far as 70% of bed length -forcing large tongue weight.
With 7k trailer and any 3/4t empty truck that is not a problem, but in your situation you don't have much given play.

The tandem will likely have MORE tongue weight on the basis that it will be overall heavier.

I did tow 18k equipement trailer with triple axle.
Pintle hook not giving any stability, yet no sway issue, unless I loaded 12,000 lb bulldozer with blade facing front.
For some reason the air flow did make the difference.