Ideal trailer/tounge length?

[Ted_Z]

Ideal trailer/tongue length?

I've been lurking on this forum for a few months, thanks for all the great information! I'm at the point of my trailer build that I've got to ask a question. You can see my build here: http://www.mallcrawlin.com/forum//showthread.php?t=19860

I plan on towing my 1/2 jeep tub trailer with my grand cherokee. The grand has a wheel base of ~110". I've read/heard several rules of thumb regarding trailer and tongue lengths; same wb as tow vehicle, 2/3 of wb, tounge 1/3 of trailer length etc.

The trailer box is 5' long, 2' behind the wheels, 3' in front (60/40 rule). I used part of the original frame to make an "A" and it will be extended with some 2.5"x2.5" box (3/16" wall). I've mocked it up for now and its 127" from the ball center to the rear bumper, or a trailer wheel base of 103". The 2.5" box tube extension is plenty long to allow for 90* jacknife.

How long should the trailer wheel base be for ideal performance? (from the ball center to the axle center).

 

[ntsqd]

My first suggestion is to put a cross member about where you have that piece of angle sitting, and extend the tongue tube back to it.

Tongue length is the easiest way to adjust tongue weight. Might leave it long until you can load the trailer, and then find the point where the tongue weight is what you want it to be.

 

[Titanpat57]

My first suggestion is to put a cross member about where you have that piece of angle sitting, and extend the tongue tube back to it.

Tongue length is the easiest way to adjust tongue weight. Might leave it long until you can load the trailer, and then find the point where the tongue weight is what you want it to be.

Good one...you beat me to the punch

Looks like a nice project!

 

[Ted_Z]

Thanks for the advice but I'm trying to get my head around why extending the tounge back to a cross-brace is required. The main frame material is 2.5"X4" 3/16" wall. The interface from the box tube to the frame (top of the "A") will have about 6" of weld and is knotched in. I'd rather not add more material as I'm trying to keep weight down to a minimum.

Anyways, back to my original question about trailer length, I'm thinking about cutting the tongue extention (2.5x2.5 tube) down to just clear the bumper during a jack knife and calling it good. That would give me a wheel base of 90". How does that compare with others peoples' dimensions?