I've never seen a limitation in GA, where did you see this?

Originally Posted by JohnBoy

I know 3 states right off the top of my head that do enforce it, Va, Ga, and Fl. The scale man in Florida stopped me on the scale just last week to let me know that I was over length by 8 inches, but because I only had 26k in the trailer he let me shorten up then go. He said the over length ticket is more than the overweight ticket.

What does GA enforce? I've never seen a max length listed for GA

Originally Posted by fortycalglock

My quote covered your points "b and c". What state uses point "a"

See what happens when you let your fingers do the waking before they wrap around the handle of a cup of coffee! NOW I SEE IT!
Now you want me to think?

That could constitute abuse......if I were 45 years younger!

been so long since I looked.....back when UT changed from 41' to unrestricted.....but you're right....only "b" and "c"!

Originally Posted by Numb

I've been seeing alot of '53 trailers going down road with the axels all the back. NOT LEGAL ANYWHERE !!

Very incorrect. Up until recently (within the last two weeks) I was dragging a 53' RGN. The only state that had a problem with it was CA. Might want to check facts prior to posting falsehoods.

Originally Posted by otherhalftw

That is part of the issue...the other side is "lift dynamics", like an airplane.

With the tandems forward, there are 2 lift points for a cross wind....in front of and behind the wheel groups...which will create a "double lift" potential. With the tandems all the way back, there is only one area for the lift, reducing the twisting effect as Hammer described.

I'm going to beg to differ on this one, Otter. While you do indeed have 2 lift points with the tandems forward, I would think the total effected area would be less. The turbulence from the drives and tandems effectively shield part of that area from the wind. By sliding the tandems back, you actually lose part of that shield, and increase the underside area affected.

The are other benefits of tandems back, though. Back does increase polar moment, meaning it takes more force to yaw the trailer; but it also shifts more of the wind load to the tractor. With the tandems back, the side loads are roughly split between the drives and the tandems. Slide that tandem 10' forward, and suddenly that changes. Now the tandem has the side load of half of the trailer in front of the tandems plus all the side load of that 10' behind the tandems. So the side load area that affects the tandem goes from 53/2 = 26 1/2, to 43/2+10 = 31 1/2.

And it gets worse. Because that 10' of trailer is now outside of the drive-tandem spread, the side force back there now has a significant effect on yaw. Take a pencil, put a finger near each end, and push in the center. The whole pencil tries to move linearly in the direction you are pushing. (Yes, the trailer still yaws, but because there is more traction from the heavier drives.) Now move one of your fingers an inch or so in from the tip and push on that tip. As Scooby would say, "Rut Roh!" Now instead of just pushing us sideways, the wind is also trying to rotate the trailer. (If you want to be absolutely correct, the wind always trying to rotate the trailer. It's just that stretched out, it pushes the nose to rotate one direction, and the trailer the other; and the structure of the trailer prevents this, leaving only a lateral force.) So by sliding the tandem forward, not only do you decrease its resistance to yaw, you also introduce a yaw force into the mix.

Those "under belly wings" on the new trailers will actually help with a cross wind....blocking the lift force generated under the trailer. As strange as it may seem...a stationary trailer will take less wind force to tip than a trailer moving forward.

Yep, while those wings do increase the total side force on the trailer, they definitely do help keep the air from the underside, reducing lift.



And I fear my cover as just another carhauler is now officially blown.