engineers whatch gonna do I have been banging heads knees and elbows with those folks for 40 years....the math tells them .. it should work... if it dosent...you did it wrong...if it works your way...then its wrong...there smart peeps but to much classroom not enough dirt....

 

You can't be serious. Take tape measure and measure from the ground to the top of the fender well. Front is a and back is b. Unloaded this is a base measurement. Just like a scale, the fender wheel is your indicator on the scale. The tape measure shows how much.

I did this with my old pickup, and empty gooseneck. I may not remember numbers right, but unloaded i was at 40.5 and 40.5. Hooked up I was at 41.5 and 39.25 After the super spring installation unloaded changed to 40 and 41.5 with the trailer hooked up Front end went to 40.5 and rear was 40.5.

That's how I used a tape measure to show that weight was moving around. Is that alot, well when 130 lb me hops into the back of the pickup and it doesn't move that much. Nor when I'm changing oil and standing on the grille guard does it move that much.

Don't forget that even though the weight in the bed only cover a small area, the force is transmits down, is transfered to the frame which transfers itself to the front and back, springs. Depending where it's located in the bed in relation to the wheels, depends how much is pushing down on each wheel.

 

You are comparing lifting the rear of the truck with airbags to putting a load on it.
This has nothing to do with the subject we are discussing here.

 

You got it. The older the engineer the easier they are to work with, most of the time.

 

What? You said

Post #11

This is new. How air helper bags can transfer the weight to the other axle?

Post 15
I know the bags will slightly shift the center of gravity UP, but how it will move horizontally?


I just told you how much change I measured using a helper spring. With a given weight. Actually there was two weights one with a load and one w/o a load. Both instances the helper spring moved weight to the front axle. Which you said can't happen.

 

12 years of schooling? I hope you've included high school as a part of that. Dang engineers have to go to more schooling than the doctors that keep them going.

There is more weight transfer than what your guestimating. Several companies manufacter air bag kits for driver comfort? If it helps with control, braking and ride quality it has to affect weight distribution also.

 

Thanks for the fun, Justin. Unsubscribing.

 

airbags do not transfer any weight to the front axle. Plain and simple.

If you hook up a gooseneck/5th wheel and your front actually raises, you have bigger problems than rear sag... or maybe a faulty tape measure.

The limit as the pressure in air bags reaches ∞ is a rigid suspension on the rear axle. Use this and test the theory. Put a jack between your rear axle and frame, then separate axle from frame while measuring weight on the front. The weight on the front won't change much.

Airbags can cause a potentially dangerous situation for conventional trailers as they take the springiness out of the rear suspension. Instead of the tongue weight compressing the rear springs a lot and lifting the front a little, there is suddenly a rigid fulcrum to lift the front... bad idea.

Airbags DO NOT transfer weight. They are simply an adjustable suspension. Would weight be transferred forward if you added a leaf to the pack? No.

 

Sooooo..... Physics vs opinion? The age old debate. For what it's worth, Kajtek's attempt to explain the physics was spot on - at least for a steady state situation. Additional stuff happens during dynamic situations, but that would only complicate things - although it would support what others have said.

But back to the headlights! Assuming you meant the car was traveling at ALMOST the speed of light..... like .9999999c...
The light would still project forward at the speed of light. The person in the car would measure it traveling away from him at c.
Then again, so would a person not in the car but standing stationary on the ground.... They would both measure it at the same speed. Time dilation and length contraction and all that stuff!
One of the first brain stretchers they go through in Theory of Relativity 101.

 

Yes you and Kajtek1 are exactly right. Airbags lifting the rear of the truck will not transfer weight to the front. Kajtek1's drawings show the situation, but people who don't understand statics and geometry may not get it. They will just assume the drawings mean nothing. At least that is what I see happening in this thread.

The reason air bags help you to control the vehicle is because the steering geometry works a lot better when the rear of the vehicle is not sagging excessively and that the air bags will help the suspension to continue to work the way it's designed to function. This is at low speed.

If you get out on the highway and drive the vehicle quickly then aerodynamics come into play. If the front is high and the rear low, the force of the air against the vehicle will tend to lift the front more than it would if the vehicle were in the inclination the designers intended.

So I'm agreeing that air bags are good and I would recommend them for leveling a vehicle used for hauling, especially on the highway. I disagree that shifting the center of gravity to the front is a reason why air bags will help.

 

For anybody,

What happens when force is applied 1 foot infront of the rear axle?

What pushes back?

What happens when force is applied 1 foot behind the rear axle?

What pushes back?

 

The highest rated tires I have found are 3750 lbs. This is really what you have to watch. Also rims. I have never had issues with tires but I have cracked rims.

 

Opposite experience here. I had several blown tires, but only 1 crack rim and that was minimal.
The tire blows I blame on the fact that darn Hancock had so long lasting thread that they aged before wear out. The crack rim I blame on the time when I tried to limp on single wheel with heavy load and second blow made me running on rims. ... with some sparks

 

Nitto Terra Grapplers in 295/70/18 are rated for 4080 lbs.

 

My tires are also rated for 4080#.

And Hakk has had a good explanation here. Maybe not weight but pressure back to the front end. Pretty close to the same thing ey?