Why are dual axle TTs made with the wheels in the middle?

[Damdifino]

Why don't you see trailers with tires at the four corners and a steer axle being in front, like an old toy Radio Flyer or even older Conestoga wagon?

[theoldwizard1]

mike-s wrote:
Steering axles are expensive and can be unstable at highway speed. For what advantage?

Eliminates porpoising on rough road. That is why farm trailers have axles set apart. Yes, you need a steerable front axle and it is a lot more expensive than a solid axle.

[sbowman871]

Ever drive behind a farm tractor pulling a hay wagon or grain wagon? They are all over the road. And backing up, forget about it

[Ski_Pro_3]

Because you can not back up a trailer like that. Consider a tow vehicle. I have one. I cannot back it up because the front wheels immediately turn to full lock, then the towbar/hitch binds up.
The axles are in the middle, more or less, on a trailer to give it the ability to back it up.

[deltabravo]

Backing would be pertnear impossible without 4 wheel steering on a tow rig.

Back when Desert Shield / Desert Storm happened, I had to get certified to tow an eleventy-million pound Missile pylon that carried 6 ALCMs on the wing of a B-52.

It was transported on a trailer that had wheels at the rear corners and a tow bar attached to a set of wheels at the front. It was towed by an ancient aircraft tug, which had rear steering. operating that mess was a nightmare when backing up. The rear steering was a lever at your left knee.

[DanNJanice]

Good question.
I suspect, as others have stated, it is because backing would be a nightmare. Yes, I used to backup hay wagons when I was kid.
I am less sure about the stability argument, as I see double and triple semi trailers all the time, they seem to work fine.

[TurnThePage]

One of the great advantages of the typical travel trailer design is that it tracks behind the tow vehicle pretty darned closely. A steer axle in front with tires at all four corners would result in lots of damaged tires and curbs with black marks.

[mike-s]

Steering axles are expensive and can be unstable at highway speed. For what advantage? Why not just mount an axle on the roof, where the brakes/bearings/tires would never wear out?

[Old-Biscuit]

Weight........

[donn0128]

Handling and control.