Understanding trailer weight distribution is critical in ensuring a safe, economical journey while towing trailers or RVs. Drivers who fail to consider trailer weight distribution are almost guaranteed to have at least one heart stopping moment during a tow, however this is totally avoidable with proper pre-planning.
The Risks Associated with Trailer Weight Distribution
Planning ahead for weight distribution can help avoid the following risks:
- Excessive wear on rear tires
- Uneven braking
- Trailer sway
- Steering Issues
- Night driving affected by headlight pattern
Before we examine how to eliminate these risks, it is important to understand why they happen in the first place. For the most part, each of the five issues listed above are due to the weight of the trailer being transferred to the rear axle of the tow vehicle. This additional weight causes the rear of the tow vehicle to lower, and the front of the tow vehicle to rise. This sagging of the rear of the tow vehicle immediately lightens the steering, and puts extra strain on the rear suspension. This accelerates wear on the rear tires, and affects the headlight beam pattern at night causing unnecessary risk at night.
Thankfully, there are off the shelf solutions to eliminate this issue, and remove the associated risks.
Managing Trailer Weight Distribution Effectively
Drivers have several different options to manage trailer weight distribution to avoid the issues listed previously. These options are all derivatives of distribution hitches and are also known as equalizers or stabilizers. The purpose of the stabilizer is to maintain the correct level between the towing vehicle and the load (trailer or RV), removing sag at the hitch. Before selecting the best product depending on your individual priorities (i.e. price/functionality/ease of use), it is important to assess the capacity you require from a weight distribution system.
In order to select the correct hitch capacity, you will require two pieces of information:
- Gross Trailer Weight (GTW) – this is how much the system can tow
- Tongue Weight (TW) – this is how much tongue weight the system can distribute
The GTW is the fully loaded weight of the trailer, as it would be if you were ready to tow it. This is measured by driving the tow vehicle onto a commercial weighing scale.
The TW is a little more complicated to calculate as you require to know the weight of the load that sits behind the tow vehicle’s axle, plus the weight of the loaded trailer that sits on the hitch. In order to measure the load behind the tow vehicle’s axle you will require to weigh your vehicle in an unloaded state, then a second weight with the cargo loaded behind the rear axle. The weight of the loaded trailer can be measured using a tongue weighing scale, or estimated as 15 percent of the total gross (i.e. loaded) trailer weight.
With this information to hand drivers can decide if they require a trailer weight distribution system, and select from the large range of weight distributions systems available. In doing so they can look forward to safer, easier driving, without fighting to control the vehicle.
The rule of thumb is to take your tow vehicles weight and divide it by two. If your loaded trailer weight exceeds this number, you need a weight distribution equalizer.
It is important to realize that you must select the weight distribution system that matches your GTW and TW closest, as more is not better with towing! Don’t be fooled into thinking that if your system has lots of spare capacity you’ll be good to go – as a poorly selected system will give you all sorts of problems.
It might help to explain with a simple example. Let’s say you have 60 lbs of gear in the rear of the tow vehicle that’s sitting behind the back axle, and a trailer load of 400 lbs. This gives you an anticipated load of 460 lbs. If you select a distribution system over 500 lbs capacity, or less the 460 lbs capacity you could experience issues. Always aim to match the weight with the capacity as closely as possible.
It’s worth noting however that a trailer weight distribution system will not increase the load capacity of the trailer or the tow vehicle, a distribution hitch’s job is to manage the weights within the manufacturers specification – not increase the load capacity.
That’s quite a lot to consider and calculate for an equalizer, and considering the potential repercussions of making an error in calculation it is worth considering referring to a professional shop for advice.
How the Weight Distribution System Works
In simple terms, the fitting process for a distribution hitch is a case of hooking your trailer to the hitch, then connect the spring bars to the trailer tongue.
Tension is created in spring bars connected to the head of the unit. This tension is created by a pair of chains that are connected to brackets that results in the bars being pulled up as the tongue weight increases. This results in the spring bars pushing upwards on the head assembly and spreading the weight to the axles and performing as an effective stabilizer.
With the connection complete all that is required is to carry out the usual trailer checks, i.e. signal and brake lights are operational.
Types of Weight Distribution Systems
A basic weight distribution system will not offer any sway control mechanism however these are easy to fit and adjust and come in a full range of capacities ranging from 700 lbs up to 1100lbs.
A basic hitch with bar style sway control is very popular with safety conscious drivers and operates using friction mechanics for sway control. Drivers will notice the benefits of sway control particularly when driving on the interstate at cruising speeds with superior vehicle control. The benefits are also noticeable when being passed by big rigs, as the anti sway technology steadies the trailer. Drivers also report increased fuel economy as a steady trailer reduces wind drag.
Take a look at more information on weight distribution hitches here.