Article - Backing Up A Short Trailer

You can backup your trailer – as long as it is long enough.

To understand why a shorter trailer is harder to backup, you need only understand a little geometry.

I remember geometry … somewhat 

If your truck is perfectly lined up with your trailer and you back up a short distance, the trailer will move a short distance back in a straight line:

On the other hand, if your trailer is turned 90 degrees such that the trailer is perpendicular to the truck and you back up a short distance, the trailer will only rotate about the center of its axle:

So, what’s the problem with a short trailer? 

The amount of trailer rotation that occurs for a given amount of backing relates directly to its stability when backing up.

To determine how much rotation will occur when backing up a small distance, you need to first calculate the distance covered by the hitch ball if the trailer were to go all the way around in a circle. That distance to go all the way around is 100% of a full rotation, or 360 degrees:

The short distance backed up is a portion of that full rotation – a percentage of 360 degrees. For a 16 foot long trailer, the distance all the way around would be close to 100 feet and if you backed up one foot, that would be 1% of a full rotation, or 1% of 360 degrees (about 3.6°). On the other hand, for an 8 foot long trailer, the distance all the way would be about 50 feet and if you backed up one foot, that would be 2% of a full rotation (about 7.2°).

This demonstrates that a trailer that is half as long will turn twice as fast. This is why it is easier to backup a 20 foot boat trailer than it is to backup a 5 foot log-splitter.

Visibility is also key

It is important to know where your trailer is when backing up. By this I mean which side of your truck is it on and how far to that side is it turned. When backing up with any trailer, you must adjust your steering when the trailer crosses from one side of your truck to the other. The more quickly you adjust your steering when your trailer crosses, the straighter your path will be.

However, short trailers tend to be smaller trailers. This is because all dimensions often scale together with the trailer length. This includes the height and width of your trailer.

Smaller trailers are harder to see. They can be down below the tailgate of your truck where they may not be easily seen in your rearview mirror. Because they might not be as wide and may not extend as far from your rear bumper, they can be harder to find by looking in your side view mirrors, and when they become visible, they may already have turned a fair amount to the side.

One solution is to get a trailer tongue extender. These will increase the overall trailer length (the distance from the tongue’s hitch ball cup to the center of the axle) and are also sometimes used to enable launching boats without putting your back wheels into the water. However, be careful not to ignore the mechanical strength issues – a longer tongue will experience greater forces due to the longer lever arm. Also, the longer tongue will lighten the tongue weight, which may require you to move weight forward to get more weight onto the hitch.

Another solution is to get a hitch angle gauge that will show you where your trailer is relative to the straight back position. The Trailer Backup Navigation Aid by TowGo, LLC incorporates a hitch angle gauge along with other measures that will help you to steer your trailer along straight or curved paths. The Trailer Backup Navigation Aid can help you backup a log splitter or other short trailer.

Dan Shepard is the Founder and CEO of TowGo, LLC, manufacturer of the Trailer Backup Navigation Aid, and is an expert on trailer backup technology.

by Dan Shepard – December 30, 2018
Copyright © 2023,2018