Why so much tongue weight on 22' car hauler trailers?

[jigs_n_fixtures]

Recommendation on Weight Distributing Hitch.

I highly recommend the WeighSafe weight distributing hitches.

They have an integral tongue weight scale built in. And they have an app, which based on the weight of your load, the tongue weight and the axle lay out, the app gives you what tongue load to adjust the hitch to balance everything out. I spent a bunch of hours watching video reviews on YouTube, before making hte decision to buy one, and it works great. I only wish that they would sell the load bars separately.

 

[hiddentacocatneddih]

I respectfully disagree. Weight distributing hitches are widely used in the RV market and make it possible to tow a trailer that is well within the total tow weight rating of the tow vehicle but is front heavy making the total hitch weight too high.

Just because they make them doesnt mean they are a good idea

RV industry is just trying to convince people to buy bigger campers than their trucks can handle.

 

[deezler]

Just because they make them doesnt mean they are a good idea

RV industry is just trying to convince people to buy bigger campers than their trucks can handle.

You need to separate those two ideas, though.

Sure, the RV dealers like to use them as a band aid on overloaded half-ton trucks.

But go out to your 1/2 ton pickup and read the owners manual. It probably says that "in order to two over 5000 lbs, a weight distributing hitch is REQUIRED". My 2500HD said the exact same thing. Sure, I could pull a loaded 10k dump trailer without a WD hitch and have no issues, but it was in violation of my manufacturers specific instructions.

Weight distributing hitches do more than just delete some tongue weight - they make the entire towing experience safer. And yes, do allow your 1/2 ton truck to get up closer to it's max towing rating on paper.

 

[Rockbadchild]

Just because they make them doesnt mean they are a good idea

RV industry is just trying to convince people to buy bigger campers than their trucks can handle.

Rams trucks are squat machines, you don't need much behind and they are squatted right up... so its ether you have air bags or a weight distribution hitch... Sure having a 2500 would be nice but to haul a camper twice a year I ratter used a distribution hitch or air bags.

 

[tradosaurus]

If you want to know the REAL reason, listen up:

If the axles were more centered, the center of gravity of the rig would be right around the center of the 2 axles. With a load placed on it, this location would pretty much be the same. Given the total mass of trailer + load, the yawing frequency would be (lets say) F_sub_yaw.

With the axles placed farther back, the yaw inertia is a higher value because of the 'axis translation' theorem (I_zz = I_zz + M*r^2). R being the altered distance. This LOWERS the natural yaw (tongue swing frequency) so it will be much more manageable. It it gets higher than about 1 Hz. you're probably not going to be able to save it if it starts oscillating above the critical speed.

Another way of saying it is that the swinging tendency will happen at a much higher speed.

That's my typical expert witness court-room testimony.

 

[Midniteoyl]

My 20' car hauler is like this also, axles set pretty far back.

However this is the correct way to make and use such long trailers. If you put the axles right in the middle, there would be a huge potential for negative tongue weight, which we all know is a terribly dangerous situation.

If you want such a long trailer, you need a tow vehicle that can handle the tongue weight, simple as that. You also MUST be using a WD hitch. Start there if not.

I also recently traded my trusty old 2500HD for a newer F150 with much lighter springs. I plan to add a pair of roadmaster active suspension springs if and when I need to start towing heavy again.

Chevrolet 1500 Silverado 1990 - 2024 | SD Kit

Kit includes an easy to install RAS Helper Spring for each rear leaf spring. RoadActive Suspension kits are designed to strengthen the rear leaf springs for towing or hauling without negatively affecting unloaded ride quality.This 3-in-1 solution works like a helper spring, sway bar and traction...

activesuspension.com

Put those on my 150. Love them..

Took the 2" spacer out from between leaf springs and axle when installing (to lower rear ride height for a better balanced look) and then set the Roadmasters to a middle pre-load tension. Truck rides and corners better with less rearend sway.

edit: Do you find the 20' trailer to be long enough for the Kioti w/loader and 3-point mower? I was thinking of getting closer to a 22', but 20's are usually cheaper.

 

[deezler]

Put those on my 150. Love them..

Took the 2" spacer out from between leaf springs and axle when installing (to lower rear ride height for a better balanced look) and then set the Roadmasters to a middle pre-load tension. Truck rides and corners better with less rearend sway.

Yeah I already removed the 1.25" spacer blocks from my rear spring perches (4wd with FX4) to sort of "level" the truck and remove some rake. And partly in anticipation of getting roadmasters. I've only read good things about them.

 

[jigs_n_fixtures]

It is important to remember, that the trailer rotates around the axles.

I’ll try not to go off into the physics of what goes on too far.

Think of the trailer from the hitch point to the center of the axle(s). This lever length for easy to follow math, I’ll do like a physicist, and make it twenty feet for convenience, knowing it is unrealistic.

The trailer will want to rotate around the center of gravity if it starts to sway. The further forward from the center of the axles, the center of gravity is, the more leverage the trailer has has to control the sway. For purposes of easy math we will say that the distance from the axles to the center of gravity is 5-ft.

So, if the trailer wants to sway and yaw, you have a thirty foot lever to stop it with. And with the hitch to center of axles of 25-ft, and teh distance to center of gravity of five feet, the percentage of the load on the hitch will be 5/25 or 20% of the total trailer load. This 20% pushes down on the rear wheels. Which in turn increases the friction between teh tire and the pavement. And it is thus harder for the trailer yaw, and sway, to push the tow vehicle around.

Down side of increasing the load on a bumper hitch, is that the load on the rear of the vehicle, causes leverage acting around the rear wheels, which wants to lift the front of the vehicle and decreases the ability to steer the vehicle.

The use of a load distributing hitch, creates a torque around the hitch, which counters the torque created by the tongue load, and put a load equal to that on the rear wheels, and make the steering stable.

None of this over rides the tow vehicles, max towing weight and GVW. Much of the GVW maximum is based on how big the brakes are. Which is why the wheel size of newer 3/4 and 1-ton trucks keeps getting larger. They need the bigger wheels, to fit ever increasing brake systems into the wheels, so they can tow ever increasing loads. Soon they will hit the max allowable without air brakes. At which point we will see whether they change the law or not.

 

[jgmo]

I'm in the market for a 22' car hauler for my Kubota. What I've been noticing is that most of the trailer length is in front of the axles, putting a lot of weight on the hitch. What am I missing here? My last 22' trailer had the same problem and I recently sold it. I was constantly being flashed at night for high pointing headlights. Any manufacturers that put their axles a little more towards the front?

Well, I know from experience that you DO NOT want that much trailer and load STEERING for you if you get the tongue weight too low!
That bad boy will toss you around like a puppy shaking a rope if it doesn't have enough on the tongue.
One method of countering the high headlights would be old fashioned air adjustable shocks on the rear of your tow vehicle.
Good luck

 

[Jaygyver]

Not all trailers can carry the same load. Whether short or long. You have to match the load to the trailer that you want or have. When maxed out the trailer axle(s) should be carrying 85/90%+- of the weight. That's how they were designed for bumper pulled trailers. How you load it is the difference. With the offset axle like the OP's picture shows, only means you should load longer/lighter loads in the front. Heavier loads still go over the axle. Having too much bumper weight is still as bad as not enough.

Fifth wheel/Goose neck trailers are just another galaxy difference compared to a bumper pulled trailer.

The reason a "semi" has the axles stretched out is because of the Federal/State BRIDGE law. Commercially, for each loaded axle weight the axle has to be a certain amount of distance from the nearest other loaded axle AND has to be a certain overall length.
If you look, sometimes you will see the tandem axle on a long trailer that has been shortened, that means they have a short heavy load on and most of the weight was on the tractor and the rear axle is now carrying the extra weight from the tractor. BUT, it still can't be over a certain weight for the shorter wheel base now. So instead of 80k they can only carry 60k or 70k total.
Google DOT state/federal bridge laws, it WILL give you a headache.