A travel trailer may have a single axle or perhaps a double (dual) axle instead.
For people who are not overly familiar with mechanical things, this is already confusing.
We get it!
If so, this article lays out the differences in layperson’s terms for you.
What is an Axle?
A tow vehicle or a travel trailer has wheels that turn because they’re connected via a rod on its underside.
This connectedness ensures both wheels turn in unison. It also makes it easier to steer because it prevents the left wheel from pointing one way and the right wheel from pointing in another direction.
With any RV being towed – be it a travel trailer, camper, toy hauler, or fifth wheel – it’s far easier to tow when it follows the path of the tow vehicle.
The axle helps to achieve this.
Single Axle vs Double Axle Travel Trailer
You may have seen that some travel trailers come with a single axle whereas others have a double axle.
That might seem confusing, but there are sensible reasons for the differences.
For shorter trailers, they’re lighter and can be supported with a tire on either side connected to a single axle. Because they’re not as heavy and are lighter, they’re an easy tow in some respects.
With longer travel trailers, they’re heavier. A single axle — with one tire on either side — supporting the entire trailer’s frame becomes too much.
Only two tires carrying a heavy load safely have their limits.
Therefore, the double axle travel trailer is used for longer and/or heavier travel trailers (and other towable RVs that match this description).
Double axle travel trailers use four tires – two on each side – with rods that connect the axles to the tires both axles together too. This proves to be sturdier.
What are Tandem Axles?
Tandem axles are another name for double axles.
It’s named this way because the wheels work in tandem with each other, rather than independently.
However, it’s the same thing as the lesser-used term. So, don’t be confused over this; it’s also a double axle trailer.
Double axles, typically with two sets of tires close together, spread the weight more evenly. Also, it reduces how much weight-bearing is necessary for each tire on the travel trailer.
Usually, the weight of the travel trailer is the main deciding factor here.
Also, dual axles are the same as double or tandem axles in the RV world. Confusing, eh!?
Single Axle Travel Trailer Pros and Cons
For a single axle travel trailer or a camper, there are good points and not-so-good points to be aware of.
If you’re trying to choose between a single and dual axle trailer, these are worth knowing because they may sway your buying decision.
Here are the single axle travel trailer pros and cons:
Single Axle Travel Trailer Pros
- Lighter trailer.
- Slightly non-level trailers still tow fine.
- Less expensive trailer.
- Improved fuel efficiency due to the lighter towing weight.
- Getting into tighter spots is easier.
- Reduced maintenance with two tires and a brake system.
Single Axle Travel Trailer Cons
- Reduced stability at faster speeds.
- Increased sway motion, most noticeable at higher towing speeds.
- Lower payload possible with single axle setup.
- Weight-bearing tires may get worn out faster.
Double (aka Dual or Tandem) Axle Travel Trailer Pros and Cons
Whilst a travel trailer may come with double axles as a reality of that product, it does have some bearing on what it’s like to tow, how much it can carry as a payload, etc.
Here are the pros and cons of double axle travel trailers:
Double Axle Travel Trailer Pros
- Improved weight distribution for heavier travel trailers.
- Supports a higher payload when on the road.
- Increased stability, especially over uneven ground, at higher speeds.
- High-side winds don’t push the travel trailer across the road as much.
- A tire blowout isn’t as dire. At least one tire on either side still supports the travel trailer making it easier to pull off safely.
- Reduced trailer sway at higher speeds.
- Holds resale value better because of expected durability vs. single axle towable RVs.
- Less towing bounciness off-road or on uneven roads.
Double Axle Travel Trailer Cons
- Worse fuel consumption due to added weight on the travel trailer.
- Higher purchase cost for two axles and four tires.
- Level towing is more necessary to prevent uneven tire tread wear.
- Higher ongoing maintenance expenses to manage four tires and brakes.
Read Also: Towing a Travel Trailer in High Winds
Single Axle Camper
For new RVers who are looking to get a camper, it’s far more common to single axle campers than dual axle ones.
Why is this?
As you might expect, the camper is shorter and lighter than the typical travel trailer on the market today. Because of this, they can be supported with a single axle instead of a double axle.
Modern tires when correctly selected will provide sufficient weight-bearing capacity to handle a camper’s payload without an issue.
Also, for newer drivers, single axle campers or trailers prove to be better to maneuver, reverse, or get parked up.
Why Do Single Axle Trailers Sway?
Anyone who has owned a single axle trailer before will have noticed that they sway at higher speeds or on the highway.
The reason is that as a single axle trailer, by default, the trailer is lighter.
Therefore, if the wind speed picks up or the tow is at a higher speed (or both), then the sway is more noticeable.
It’s still possible that a lightweight dual axle travel trailer could have some sway…
We’re not saying that the introduction of two additional tires and a second axle prevents it.
Yet, all things being equal, a double axle trailer tracks the direction of the towing vehicle more closely.
Read Also: Towing Fifth Wheel with Lifted Truck
Are Single Axel Travel Trailers Safe Enough?
While you may be considering purchasing the best single axle travel trailer, hold up. Is a double axle travel trailer going to be safer? Let’s evaluate that a little first…
It’s advisable to tow at a lower speed when pulling a single axle trailer or camper. This helps to avoid towing complications.
In a heavy storm, a single axle travel trailer or camper is a little likelier to be blown over compared to a dual axle trailer.
However, more concerning is a potential tire blowout on the highway.
With just one tire on each side, should either one suffer a surprise blowout, the travel trailer will slump to that side, and could overturn.
With a double axle, hopefully, the second tire on the affected side will remain inflated.
This will allow greater control to safely reach a full stop and avoid the potential of it ending up on its side or the roof.
Metrics to Be Aware Of
One of the most useful weight measurements for a trailer is the Gross Trailer Mass.
While state laws do vary on this matter, many states don’t yet require a single axle travel trailer (or camper) to have brakes installed.
The cut-off on the Gross Trailer Mass also varies and can be near to 800Kg, 1,000Kg, or higher.
Therefore, a single axle towable may not come with brakes fitted. Then you’re relying on your truck or another tow vehicle to do the job.
Are its brakes powerful enough to stop both the tow vehicle and the travel trailer?
Also, the stopping distance will be longer, especially in a rainstorm. So, don’t forget that too.
Look at the towing capacity of your tow vehicle to see if it’s up to the task!
The Gross Vehicle Weight Rating (GVWR) is worth a look. It denotes the weight your tow vehicle can handle with the driver, passengers, and the trunk filled up.
Also, the Gross Combination Weight Rating (GCWR) matters as well. It confirms the maximum weight for a fully loaded trailer, and what’s included in the GVWR already.
Furthermore, we’d be remiss in failing to mention the Gross Axle Weight Rating (GAWR) too.
The GAWR is the maximum that a single axle can support, which is especially relevant for single axle trailers or campers.
Are Small Dual Axle Travel Trailers Safer?
When looking at a dual axle travel trailer under 3500 lbs, they’re going to have four tires and an ample brake system.
It puts less strain on the towing vehicle where both the tow vehicle and the travel trailer are breaking in partnership.
Even a small dual axle travel trailer is not likely to sway as much.
It’ll also travel more in a straight line, more closely tracking the direction of the towing vehicle.
Towing becomes more predictable and less tiring for the driver when covering many miles each day.
There is a place for a single and a double axle travel trailer (or camper). As indicated earlier, there are both pros and cons.
So, it’s important to correctly assess the priorities of you and your family before making a final selection.