53' spread axle load center point

Measure from kingpin to center of axles. The exact midpoint of that line will be load center. Now adjust for the extra unladen weight on the drives.

 

Depending on king pin setting and weight of the truck that does work

 

King pin setting doesn't matter. Its why you measure from the king pin. And obviously you have to adjust the load for the weight of the truck cause no two trucks weigh the same, even exact same models will have slightly different weights due to what one driver packs inside vs another.

 

MATH TRICK

measure the distance between kingpin and CENTER of the spread
then axle-weigh the unit
subtract the tare weight from 80,000 to get max load (g)
subtract drive axle weight from 33,500 to get max load on drives (d)
divide (d) by (g) to get a percentage expressed as a decimal
multiply the distance (kingpin to axle center) by this decimal
the result is the distance from axle center forward

example:
kingpin to axle center measures 41 feet
unit axle weights 12000 steer
10200 drives
9300 trailer axles
80000- 31500=48500 load weight
33500-10200=23300 max drive weight
23300 divided by 48500 = .4804
41 feet X.4804 = 19.69 feet

 

With a 53 foot trailer, the load center will be forward of the exact center of the length of the trailer. The fast down and dirty way to find load center. Measure and mark 24,25 and 26 feet from the front edge of the trailer. If the center of the load is between these marks, you should be good. If it is off a bit, your only a small adjustment to good. May only need to move dunnage.

 

Just not sure why you wouldn’t just measure form the kingpin to the center of the rear axle group and mark that as center?

If you want to get technical figure out the percentage of your max bet payload that can go on your drives plus steers

Then divide that by the total net and multiple that percentage by the length from the king pin to center of rear axle group and mark that distance as center of weight.

 

Someone else posted a different scenario for finding weight center a few years back. But it was more or less the same thing discussed here.

I can't remember the math but it was something like 1 foot front or back of turn signals. Which are usually dead center of trailer length. I want to say it was front. As that would be less space to take drives into consideration where as rear would have more space for the lighter spread axles. On a 48 flat.

If i remember right. A 53 would be the turn signals. Dead center of trailer. With the axles open. No idea on axles closed.

 

Load center will move based on axle set.
Fixed Cali spread
Fixed 44 spread
Slides spread to tandem

 

Center of trailer is between kingpin and center of spread. Move it back to adjust for the difference of weight between your drives and spread (drives are bearing weight of trailer and tractor and will be more than spread), then go a lil bit more (less than a foot) depending on the load to play it safe since you are allowed 40 on the spread vs 34 on drive. The closer you are to 80 the more precise you will need to be. Depending on trailer should be in the ballpark near center light but dont base it on that. Thats the easiest on the fly way at a shipper with out doing crazy math.