If you’re new to the towing or boating field, then you need to accurately calculate your tongue weight. It may sound funny, but tongue weight is one of the most important towing terms you need to know to avoid accidents on the road.
If you’re wondering: “boat trailers with too little tongue weight tend to do what?”, then this article is for you. We’re answering all questions related to the tongue weight of a boat trailer, so keep reading for more information.
What is Tongue Weight?
If you’re planning on towing a boat trailer behind your vehicle, you better be ready to get familiar with a lot of towing terms including “tongue weight”.
Tongue weight (TW) is a unit that refers to the amount of force applied downwards by the tongue of the trailer onto the hitch of the towing vehicle.
To make the rest of the article simpler, think of the trailer as a lever and the axle (or pivot point) of the trailer is the fulcrum for the lever.
If the tongue is too light, you’ll have to transfer more of the load weight forward of the trailer’s axle. Similarly, if the tongue is too heavy, you’ll have to move more of the cargo weight behind the trailer’s axle.
How Much Tongue Weight Should a Boat Trailer Have?
To understand how the ideal tongue weight of a boat trailer is calculated, we need to talk about another towing term called gross trailer weight (GTW).
Gross trailer weight is the total weight of a trailer after it’s been fully loaded. This weight rating isn’t determined by the manufacturer or a specific weight addition equation.
Instead, you measure the gross trailer weight after you’ve placed all of your camping gear, snowmobiles, firewood, passengers, or any other cargo into or onto the trailer. In other words, any weight added to the trailer is also added to the gross trailer weight.
As a rule of thumb here, the tongue weight of a boat trailer should fall somewhere between 9 and 15 percent of the total weight of the trailer. Many experts agree that 6 percent allows single axel models to perform best, while 5 percent allows dual axel trailers to perform best. However, a higher ratio is usually required for trailer campers and other larger units.
What Do Boat Trailers with Too Little Tongue Weight Tend to Do?
If the tongue of the boat trailer doesn’t apply enough downward force on the hitch ball of the towing vehicle, this means that the boat trailer has too little tongue weight.
When the tongue weight of a boat trailer is too light, it tends to cause a dangerous movement called fishtail movement. This is a swaying motion resulting from the towing vehicle lifting at the back, putting the towing vehicle and boat trailer out of control.
This can easily lead to overturning or skidding. This can cause the towing vehicle and boat trailer to leave the road or hit other cars on the road.
What Do Boat Trailers with Too Much Tongue Weight Tend to Do?
If the tongue of the boat trailer exerts an excessive downward force on the hitch ball of the towing vehicle, this means that the boat trailer has too much tongue weight.
When the tongue weight of a boat trailer is too heavy, it tends to cause the towing vehicle to sag down, which can be followed by uncontrolled pushing of the tow vehicle.
Too much tongue weight can also lead to problems with braking distances, driver visibility, overall handling, as well as a strain on the transmission and an increase in fuel cost.
Why is Tongue Weight Important When Towing a Boat?
If you fail to calculate your trailer’s tongue weight correctly, then you’re risking getting into a serious accident on the road, jeopardizing your life and that of others.
Your vehicle and boat trailer could start fishtailing and swaying, which could make you lose control of your vehicle. This may lead to an array of issues on the road, and in the worst-case scenario, could result in a fatal accident.
To avoid all that, it’s critical that you correctly determine your gross trailer weight to accurately calculate the tongue weight when towing a boat.
How to Calculate Tongue Weight?
As we mentioned above, your trailer tongue weight should be somewhere between 9 and15 percent of the gross trailer weight. As such, the first step to measuring the tongue weight of your boat trailer is to determine your GTW.
Luckily, figuring out your gross GTW doesn’t involve complicated equations or procedures. It’s pretty simple actually, all you need to do is drive your trailer onto a scale large enough to accommodate a trailer.
Most areas have local public scales that you can use for just a few dollars. When it’s your turn on the scale, follow the steps below to make sure you get an accurate gross trailer weight reading:
- Disconnect the trailer from your tow vehicle. Remember, you want the weight of the trailer alone, so make sure to pull the towing vehicle far enough forward to not touch any part of the scale.
- Make sure that the whole trailer is on the scale. This includes all of the wheels and the trailer tongue. If the tongue is outside of the scale, the reading could be anywhere from 9 to 15 percent less than the true gross trailer weight.
You can take either a fully loaded trailer or an empty trailer to the scales. If you take a fully loaded trailer, you’ll know how heavy that particular load is.
However, if you take an empty trailer, you’ll know the empty weight. This means you’ll always know the starting weight of your trailer before you begin loading cargo.
From this point, you just need to keep track of the approximate weight of the added load. This will give you a close estimate of the gross trailer weight every time you load up for a trip, saving you from repeated visits to the scale.
Wrap Up
There you have it, boat trailers with too little tongue weight tend to sway dangerously into a fishtail movement. This could lead to overturning or skidding, risking your life and that of others.