web page or plans that show proper trailer building measurements (tongue length)

[slickrock]

Some of you have seen my trailer build from an old harbor freight 3x3. I need to make my tongue longer but I am worried about weight disbursement. Does anyone know a web page that gives the basic formula for proper tongue length versus axle placement.

Is it 40% of the length behind the axle and 60% of the length in front of the axle including the tongue length or does the tongue length matter? The minimum tongue length will be to be able to have the trailer 90 degrees from the cruiser’s body without hitting anything. (tight turns/backing up, I need about another 2' so my tongue length will be 3.75 feet form the deck). Is this about right?
Sorry for all the random posts, but I do not want to have to rebuild again.

 

[ranger]

I built a trailer from the back end of a 40. I know there is math invovled in proper length, but since the trailer wasn't towing a ton of weight I just guesstimated.
My first setup towed well, but in tight turns the box I had mounted to the front of the trailer would hit the rear corners of my cruiser. I lenghtened the the tow tongue by two feet and that workedl. SInce I don't have the trailer anymore I'm not positive how long it was exactly, but if memory serves correctly it was about 4' total.
The key to towing is tongue weight, you can increase or decrease this by how you load your trailer. I took pretty much the same junk everytime I went camping, so I knew how to load the trailer so it would work. (about 100 to 150 lbs on the tongue) It was a trial and error thing to get it right.

 

[Brian in Oregon]

Excerpt rom http://www.pte.state.id.us/ast/astdocs/curr/240/240-J.DOC
I've omitted the references to goosneck trailers. This is a teacher's guide to a student trailer design project.

J. Tongue and Overhang Lengths

1. The length of the tongue determines how a trailer will react when backing. A shorter tongue will allow a trailer to turn quicker than a longer tongue.

2. Tongue or overhang lengths should be long enough to allow the tow vehicle to turn as sharp as possible without hitting the trailer with the corner of the bumper.

a. Measure from the center of the ball to the outside corner of the tow vehicle. The tongue should be at least this long.

3. 42" to 48" is common for tongue lengths.

K. Tongue and Overhang Heights

1. For bumper pull trailers the hitch coupler should be about the same distance from the ground as the main frame of the trailer. Ball height of the tow vehicle can be adjusted to compensate any differences.

If you're a real glutton for punishment, here's a webpage with all sorts of trailer math to drive you crazy. It's mainly for a single axle boat trailer, but the boat can easlily be substituted with a theoretical mass in the cargo box or on the flatbed. Just estimate a reasonable center of gravity and reasonable cargo weight. This design in concept is not far from what you've actually made, though of course they look and function differently. One thing is obvious - your axle is set back quite a bit for cargo on the platform, whereas if it was a boat trailer, the motor would balance the center of gravity out better.

http://continuouswave.com/whaler/reference/trailering/trailerCalculations.html

 

[slickrock]

thanks.

I made my tongure a little over 4 foot. seems liek it shoudl work and clear the sides of the cruiser.

 

[REZARF]

Here you go, some good info here.

http://www.championtrailers.com/UTILITY_TRAILER_KITS.HTM

Rezarf <><

 

[alf]

I have the scale drawings of the m101 canadian in .pdf if you would like them.

Anyone who wants them please send me a direct email so I can send the file.

klschulte@esamjones.com