How To Determine Proper Axle Placement On Single Axle Trailer

Updated 08/24/2015 | Published 08/23/2015

Question:

building a trailer specifically for a generator that weighs 1100 # it is 52 inches long and 32 inches wide. i have the frame constructed but have not installed the springs. Do I use the placement of axle to have 60 of weight behind or in front of axle?

asked by: Gary G

Expert Reply:

Using a 60/40 ratio is a great place to start when deciding where to place your axle, placing 60 percent of the weight in front of the axle. However, there are a couple other factors that come into play. I have attached a photo that outlines that equation you will need. Mocking up the design will be the easiest way to determine the correct location of your axle.

As a start, you will want to determine the approximate 60/40 location of your axle. For example, if your trailer is 84 inches long, you will want to start with your axle approximately 50-13/32 inches from the front of your trailer. The equation explained in the photo will help you adjust this distance for the correct location.

The other measurements you will need are the weight of the trailer and the trailer's tongue weight. The tongue weight will be easiest to determine if you have a mock up of the trailer.

The equation you will use will depend on if the trailer's tongue weight is more than or less than 10 percent of the trailer's total weight. The total weight of the trailer is equal to the tongue weight plus the weight of the trailer under the wheels.

expert reply by: Victoria B