Community Forums

xrated · 09-25-2018, 04:29 AM

Quote:

Originally Posted by tfryman

15% of the weight of your trailer should be on the tongue; otherwise sway will be a problem.

Simply adding a spare tire to the rear bumper on a trailer that is borderline on tongue weight will make that trailer susceptible to sway.

That statement ^^^^^ isn't fact! Normally the range of suggested tongue weight is 10 - 15%, and every trailer is different on how it will tow with a given amount of tongue weight. For example, my Toy Hauler (13,000 lb GVWR) typically has just under 11.5% of its weight on the tongue and zero sway issues using a Blue Ox brand weight distribution hitch.

KF7DAJ · 09-25-2018, 04:49 AM

Quote:

Originally Posted by Tradevman

First off apology if this has been brought up before. Need clarification on the weight inside my 25ft Rockwood Mini Light. Tow vehicle at this time is a Jeep Commander with the Hemi engine and tow package. I have a weight distribution hitch with a antisway bar.

First time I towed it anywhere I had a problem with trailer sway every Time I got over 45mph or close to 50mph. I was told that I had to much weight in the rear of the rear of the TT. The next trip I made sure most of the weight was moved to the front of the trailer. Very little to no sway up to 60mph, all was good.

So hear is my question. I have seen pictures of folks adding, Modifying, hanging generators and other items on the back of their TT's. I don't understand how they can do this and not get trailer sway. Does it have to do with also adding some weight to the front to balance it out? Very Puzzled.

No one answered one of the op's original questions.
Adding weight to the rear of a trailer like you see in this picture would depend on the trailer. This looks like a a heavier trailer that would have strength and stability for the extra weight. A ultra-lite trailer is not designed for adding much extra weight to the rear bumper.
The frame will not handle the extra load. They are designed to be lighter so they can be towed by smaller vehicles.
A heavier T/V like a 3/4 ton truck would allow you to store all kinds of toys in the bed, and still have plenty of gvwr to tow your current (and future) trailer.

ScoobyDoo · 09-25-2018, 07:50 AM

Quote:

Originally Posted by Demiles

A longer wheelbase vehicle doesn’t mask anything, it will raise the speed at which sway will occur by moving the TV COG further away from the rear axle. It has the same effect as improving load conditions in the trailer.

Moving the COG of TV forward can help the control of a swaying trailer, but will not stop the trailer from swaying. And another issue is the longer overhang, moving the ball back from axle can cause issues. My Dad had a TT that towed ok behind his van. Bought a extended cab, long bed F150. His first trip, I had to take my F-5 to bring the trailer home from the rest area.

Tradevman · 09-26-2018, 07:02 PM

Xrated, you brought up something I hadn't thought of, ToyHaulers. They are designed to carry a lot of weight in the rear, are they not?? So what keeps them stable?

ScoobyDoo · 09-26-2018, 07:57 PM

Quote:

Originally Posted by Tradevman

Xrated, you brought up something I hadn't thought of, ToyHaulers. They are designed to carry a lot of weight in the rear, are they not?? So what keeps them stable?

I have not paid a lot of attention, but I would guess the axles are set back compared to normal TT, and the TW of the MT TH is more than average for a RV.
BTW, I built a trailer with a MT weight of 8,600 lbs and loaded near 45,000 lbs. TW, was the same, about 400 lbs MT or loaded. Tracked like it was on rails, at any speed I wanted to pull it...

Demiles · 09-27-2018, 03:15 AM

Quote:

Originally Posted by Tradevman

Xrated, you brought up something I hadn't thought of, ToyHaulers. They are designed to carry a lot of weight in the rear, are they not?? So what keeps them stable?

The key word there is designed. Empty they carry much more weight up front so adding weight in the garage is part of the design. Even then just like any other trailer if you load it to heavy in the rear and lighten TW too much you will have instability.

CharlesinGA · 10-01-2018, 09:52 PM

Having all of your weight at the extreme ends is not good either. The OP wanted to know if its possible to compensate for extra weight at the rear, by adding up front. Yes, it will balance that way, but as Demiles alluded to, what he described as "high yaw inertia", I simply describe as the "barbell effect". Pick up a barbell, even a light one, with say ten pounds on each end. Have someone give it a shove on one end (as if a blast of air hit it from a truck passing by). How hard is it to control? a bunch, due to the weight at the extreme ends and the inertia they have. Slide both of those weights to the middle and then have someone give it a shove, easy to control with all the weight focused in the middle.

While the trailer may not sway, its balanced correctly with the magical 10% to 15% on the tongue, it still has instability should something set it to swaying.

What does being level have to do with it? well, its simple, the trailer has height, and thus weight up high, the structure of the trailer, the fridge, storage compartments and the A/C too. Raising or lowering the tongue has the trailer pivoting at the axle or between the tandems. Look at the trailer from the side. Imagine a slice of pie that has the point at that pivot point, and extending straight up from there. If you tilt the trailer back (tongue up) what happens to the pie slice? all of it ends up behind the pivot point below it, thus more weight aft. Lower the tongue and the pie slice pivots forward, putting more weight on the tongue. There is more to it that this, but this is a major part of it. At work, when we weigh airliners, they have to be level, just for this reason, raise the nose and it gets light and the other load cells see more weight, and it doesn't take much either. I think most of the aircraft require we be within a quarter of a degree of level.

Charles

Tradevman · 10-05-2018, 05:08 PM

Thanks, makes since on the balancing of the trailer to keep down the chance of sway.

So better to keep the weight centered rather then on the ends, and a TV with a longer wheelbase would be better then my Jeep Commander.

If most of the max weight is centered, how do you know if you are exceeding the 10/15% of the tongue weight? Still only a factor of the gross weight? And is this only found in the trailer specs? Can't seem to find anything about tongue weight on my Jeep.