Does the tail wag the dog?

[HighFlying]

Back when I was younger than I am now, I had the tail wag the dog. I was moving and was pulling a U haul trailer from Tulsa OK to Wichita Falls Tx and had loaded the trailer wrong. As Andy said it's all about proper set up and loading, I was young and inexperienced and loaded some of the heaviest items at the back of the trailer, and didn't have the proper loading of 12-15% on the tongue. This combined with too much speed, I all but ended up in a ditch upside down and possible dead. An 18 wheeler behind me saw what was happening and moved over in the middle of the road to keep anyone from passing him, and by just pure luck or someone above looking out for me, I got the thing under control with no damage. My poor dog was in the back of my blazer being slammed from side to side in the most violent way imageable, when the trailer wags the truck, I can attest that it is very violent and no fun.

Skip forward 25 years and a 34' Airstream classic and a 2011 Chevy 3/4 ton HD Duramax Diesel with sway control from the factory and a Pro pride hitch, I can say you will not even notice when an 18 wheeler passes you. Its a none event, so much so that my wife who would never drive before I had this hitch, drove this summer on a 4 thousand mile trip, about half the time. So again I will echo what Andy said, get the proper truck, proper hitch, and lastly but not least, have it set up properly, and you will fell and be much safer.

[m.hony]

I think the truck does all that wiggling around without a trailer because it is big, heavy, wide, long, and top heavy.
Another contributing factor is the rough, lumpy, bumpy roads. The gubment is broke. The road bed is all broken down and worn out under the asphalt. Asphalt is basically liquid and never stops "flowing" under the weight of constant 18 wheeler traffic.

[JDnBeastlet]

Originally Posted by dkottum

When I learned the Hensley/Propride hitch design eliminated trailer sway (tail wagging dog) it became clear these sway conversations are not relevant in this age of towing. If this concerns you, you don't need a bigger truck to mask trailer sway, you need a modern hitch to eliminate it.

doug

Not sure I'd agree that sway conversations aren't relevant, but we've towed over 20,000 km with our ProPride 3P and I can affirm that it eliminates sway completely.

[dkottum]

Originally Posted by JDnBeastlet

Not sure I'd agree that sway conversations aren't relevant, but we've towed over 20,000 km with our ProPride 3P and I can affirm that it eliminates sway completely.

Perhaps that's the point I attempted, with the Hensley/ProPride design trailer sway concerns are no longer an issue.

I will say we never felt sway with two other hitch designs either, but I knew it was entirely possible and disastrous. I've seen the results. We also felt the steering inputs of passing trucks during strong crosswinds, gusting sidewinds, uneven roads, and steady strong crosswind. It was there because the trailer was moved to a slight angle behind the truck. That's not possible with the 3p style hitch.

doug k

[JennandJerry]

I do not believe you will ever completely eliminate tail wag..just minimize it. If 18 wheelers can't stop it neither can we! However, a good load equalizing hitch helps tremendously. I do not know why someone would pay $40,000 to $120000 for a trailer and $40,000 to $60,000 for a vehicle and put it at tremendous risk by not taking the logical steps to insure a safe ride. When I purchased my airstream the first thing I checked was GVWR required for it. With those matched, electric breaks, load equalizing hitch, an sway bars came next. With those installed I took a 7000 mile trip through the rockies to SF, LA, and back home. This was the third such trip. The first a pop up, the second a echo trailer, and then the queen. The Airstream handled better that the two smaller trailers and gave me better Gas mileage. It is more like driving a 45ft vehicle than a trailer. The real test will be in snow and ice (soon coming)

[dkottum]

Originally Posted by JennandJerry

I do not believe you will ever completely eliminate tail wag..just minimize it. If 18 wheelers can't stop it neither can we! However, a good load equalizing hitch helps tremendously. I do not know why someone would pay $40,000 to $120000 for a trailer and $40,000 to $60,000 for a vehicle and put it at tremendous risk by not taking the logical steps to insure a safe ride. When I purchased my airstream the first thing I checked was GVWR required for it. With those matched, electric breaks, load equalizing hitch, an sway bars came next. With those installed I took a 7000 mile trip through the rockies to SF, LA, and back home. This was the third such trip. The first a pop up, the second a echo trailer, and then the queen. The Airstream handled better that the two smaller trailers and gave me better Gas mileage. It is more like driving a 45ft vehicle than a trailer. The real test will be in snow and ice (soon coming)

Tail wag is completely eliminated by the Hensley/ProPride linkage design. Conventional sway control hitches don't have it, nor do 18 wheelers. The trailer is locked from turning the tow vehicle, but the tow vehicle can easily turn the trailer.

Snow and ice add another problem to conventional friction sway control hitches. When the trailer moves out of alignment with the tow vehicle, the friction resists it from returning to straight alignment. This can be a serious control problem. Some people loosen the friction bar on the hitch to help, but there goes sway control. The Hensley/ProPride does not resist returning to straight line when the tow vehicle steers out of tow vehicle/trailer alignment.

doug

[JDnBeastlet]

Originally Posted by dkottum

Tail wag is completely eliminated by the Hensley/ProPride linkage design. Conventional sway control hitches don't have it, nor do 18 wheelers. The trailer is locked from turning the tow vehicle, but the tow vehicle can easily turn the trailer.

Precisely. I have tried to induce sway in the trailer by wagging the nose of the dog but the tail just follows obediently behind.

We habitually tow at 90 km/h (56 mph) and when on major highways we're constantly passed by large trucks and buses, sometimes at high speed. The effect is the same as if not towing - the entire rig gets pushed outwards by the bow wave of the passing vehicle. Crosswinds are similar; The entire rig is affected. No sway. Not even a little. Ever.

[dwightdi]

There are still more Reese and other older hitches on the road that the combination of Arrows and Proprides, so this thread is relevant. To be scientifically correct, PP and Arrow minimize tail wagging, but do not eliminate it. Their 4 bar linkage simulates, or transposes, the pivot point to about the center line of the rear wheels of the TV. This is similar to what a Pullrite, 5th wheel, or a semitrailer truck does. The bow waive effect, from the passing trailer truck, is still there, but its effect on the steering effort need by you is minimized by the shift of the pivot point. The old International IH's, with the blunt nose cab-over design, were the worst.

[perryg114]

The friction sway control devices work and I almost had a wreck a while back when I hit a rough patch of road and swerved. The trailer starting oscillating. I hit the trailer brakes and things calmed down. I had loosened the friction bar because that is what the instructions say while towing in the rain. DON'T ever do this because then you have no sway control. Any tail wagging event can start the trailer swaying if you don't have enough damping or a sway eliminating hitch. I was lucky and I knew what to do to by hitting the trailer brakes.

Perry

[Inland RV Center, In]

Originally Posted by perryg114

The friction sway control devices work and I almost had a wreck a while back when I hit a rough patch of road and swerved. The trailer starting oscillating. I hit the trailer brakes and things calmed down. I had loosened the friction bar because that is what the instructions say while towing in the rain. DON'T ever do this because then you have no sway control. Any tail wagging event can start the trailer swaying if you don't have enough damping or a sway eliminating hitch. I was lucky and I knew what to do to by hitting the trailer brakes.

Perry

The Reese torsion sway control, works even under water.

The reason the friction sway control must be released when in the rain is that it can cause a loss of control accident, by being unable to move, which in turn causes the trailer or tow vehicle to skid.

Andy

Andy

[dkottum]

Originally Posted by dwightdi

There are still more Reese and other older hitches on the road that the combination of Arrows and Proprides, so this thread is relevant. To be scientifically correct, PP and Arrow minimize tail wagging, but do not eliminate it. Their 4 bar linkage simulates, or transposes, the pivot point to about the center line of the rear wheels of the TV. This is similar to what a Pullrite, 5th wheel, or a semitrailer truck does. The bow waive effect, from the passing trailer truck, is still there, but its effect on the steering effort need by you is minimized by the shift of the pivot point. The old International IH's, with the blunt nose cab-over design, were the worst.

The way I understand it, the Hensley/ProPride linkage not only projects the pivot point forward, it also "locks" the trailer from moving out of alignment with the tow vehicle. Only the tow vehicle steering can change the alignment. That would be an additional factor to prevent sway that fifth wheel and semi trailers do not have.

There is a video somewhere demonstrating that additional feature with a Lego model. Quite interesting, anybody have the link?

That is what makes the driving experience in buffeting side winds and bow wave from passing trucks so much more pleasant than other sway control hitches.

There are limits for sure. If the side forces on the trailer were extreme, the whole unit, truck and trailer could lose traction. For example another vehicle hitting the trailer, or extreme straight line wind in front of a severe thunderstorm. That's a matter of safe driving or sensing when to get off the roadway. It is not "tail wagging" that will get you, it's the extreme force.

doug

[mandolindave]

Some of us are talking about stopping the tail from wagging by using anti sway controllers. I would like to add that the tail doesn't have to be wagging, to affect the tow vehicle. If you are slowing down to quick on a curve, the trailer can push around the rear end of the tow vehicle, especially on gravel. This situation, and oscillating sway, are controlled by applying just the trailer brakes. Also, I can really feel it when my water tank is half full. The weight of the water sloshing around can really be felt.

[graysailor]

The video above was a major selling point for me. After 5 weeks of RVing I am aware that I have a trailer behind me but no real feelings of the tail wagging the dog.

[dkottum]

Why the tail can't wag the dog.

The Hensley/ProPride linkage demonstrated with a model:

Lego Hensley Arrow Model - YouTube

doug

[perryg114]

I bet I could make one of these cheaper than buying one if I had one to look at.

Perry

[Stefrobrts]

Perhaps it is because we have a BIG van, and a tiny trailer, but we have never felt our trailer do anything even the slightest bit out of control behind us. It follows along in a perfectly well behaved manner, even when being passed by speeding semi's and being buffeted by strong winds coming off the Columbia. Even if we've forgotten to hook up our friction sway control. Even when we switched to towing on the ball alone with no WD. Indeed we may feel a little push from big trucks passing, but I would feel that in the slab-sided van anyway. Of course on the next trip out, everything could go to hell, who knows, but the last ten years have been extremely uneventful. Sometimes after reading these threads on here, I wonder if I should get out while I'm ahead.

[dkottum]

In over 50 years of driving I've never needed my seat belt, always a PIA to hook up and added a bundle to the cost of my cars and trucks over the years.

I wonder if I really need it.

doug

[Garfield]

Originally Posted by dkottum

In over 50 years of driving I've never needed my seat belt, always a PIA to hook up and added a bundle to the cost of my cars and trucks over the years.

I wonder if I really need it.

LOL Do you feel lucky?

[LFC]

Originally Posted by dkottum

Why the tail can't wag the dog.

The Hensley/ProPride linkage demonstrated with a model:

doug

Funny how he barely moves the Hensley and wiggles the other like crazy.

[perryg114]

It can cause a loss of control incident if it is loose as well. The only circumstance where I would see it would lead to problems is when the trailer is hydroplaning, in which case you are already in trouble.

Perry

Originally Posted by Inland RV Center, In

The Reese torsion sway control, works even under water.

The reason the friction sway control must be released when in the rain is that it can cause a loss of control accident, by being unable to move, which in turn causes the trailer or tow vehicle to skid.

Andy

Andy