Single vs. Double vs. Axle-Less Suspension
Finding a trailer that suits your needs starts from the ground up. To select the right trailer, start by figuring out how much equipment or supplies you need to carry and what type of roads you need to travel. If you need to carry substantial weight on your trailer, you might need more than one axle to distribute the pressure more evenly.
What is an axle?
The axle is any bar, rod, or spindle secured to the center of a set of wheels to retain their positions during rotation. The word axle delineates from the Greek word “axon,” which means axis or wagon. In the 1500s, axles were made from wood and referred to as the axletree. Nowadays, axles have a wide array of fabrication styles and technologies to enable highway or overland transportation.
What are the different parts of an axle?
The primary component of any axle is the shaft, or the beam, to which the wheels are attached. Bearings on either side of the axle allow for the actual rotation of the wheels on a trailer. Finally, a wheel flange joins the hub of the wheels to the shaft.
Differences between single & double axles
Some trailers have two axles to accommodate larger loads — or in the case of campers, a larger living space or heavier chassis. A longer trailer might require two axles to increase stability during travel. These campers can also be called “tandem axle” or “dual axle” trailers. Towing, length, trailer weight, and torque are all determining factors for the number of axles required.
Pros of single axles
- Easier to maneuver – fewer wheels means a tighter turn radius resulting in a more maneuverable design. Over rugged terrain, having fewer points of contact with the road and less rolling resistance allows single-axle trailers to traverse obstacles with greater ease.
- Fuel efficient – having one less axle means a lighter-weight trailer. You’ll use less fuel when towing a single-axle trailer when compared to a tandem-axle trailer.
- More affordable – in general, single-axle trailer designs demand fewer parts and labor from manufacturers leading to lower market prices. They also cost less to maintain as you won’t have to replace as many parts during service intervals.
- Less maintenance – compared to a dual-axle, you’ll need half the grease and spare parts to fix a single-axle system. Also, there are fewer parts that run the risk of breaking when compared to a trailer with two axles. Moreover, you won’t have to replace as many tires on a single-axle as you would on a dual-axle trailer.
Cons of single axles
- Less stable – fewer tires means less contact with the road and less overall stability. Although they are easier to maneuver, one-axle trailers don’t distribute heavier loads as evenly as dual-axle setups.
- Less carrying capacity – one set of tires can only carry so much weight before reaching their limit. Trailers in construction or landscaping jobs carrying tons of equipment need more axles to distribute the weight.
- Need a jack to replace tires – a flat tire on a single-axle trailer forces you to stop and address the issue. Without four tires, a single-axle leans towards the side with the flat and requires a jack to install the new tire.
Pros of double axles
- Brakes – because dual-axle trailers carry larger loads and gather more momentum, they usually come with braking systems installed. Either stand-alone hydraulic or electric brakes wired into the towing vehicle work to slow the momentum before a stop.
- Easier to change a flat – extra tires means less worry when flats happen. If one of the four tires on a dual-axle trailer goes flat, you’ll still have a good tire on either side.
- More stable – with two sets of wheels, the weight on a trailer is distributed more evenly over a larger surface — making double-axle trailers more stable in poor conditions.
Cons of double axles
- Heavy – along with an extra axle comes added components and weight from all those parts. Extra axles can add hundreds of pounds to a trailer causing you to burn more fuel while towing.
- Wider turn radius – dual-axle setups are often longer and take up more space on the road. Finding parking spots and making 180-degree turns is difficult with two-axle trailers.
- Costly – besides maintenance, trailers with more than one axle have a higher market price and accrue higher pay toll fees on the highway. As mentioned, you’ll need more gas to tow two axles and stop to fill up your tank more frequently.
What is axle-less trailer suspension?
Axle-less suspension, or trailing arm suspension, is common for aircraft landing gear. The wheels on an axle-free suspension system are attached to an arm-like spindle, while bushings provide shock absorption between the frame of the trailer and the spindle. Wheels on an axle-free design move independently from one another and limit sway and rock while driving over bumps or potholes. The absence of an axle allows for greater ground clearance and versatility over uneven terrain — therefore, this is a choice suspension system for overlanding camper trailers.
Pros & cons of axle-less suspension
Axle-free suspension systems have all the same benefits as single-axle suspension but with greater stability and clearance. The only drawback to not having an axle is a slight decrease in carrying capacity; however, this is hardly a concern if you’re not using your trailer for construction.
Get a trailer with stronger, lighter suspension, & more ride height for any trail
At TAXA, we design overland habitats with suspension systems that don’t compromise carrying capacity or stability. Our spacious, axle-free trailers can provide enough living space for a whole family while retaining all the versatility of a single-axle trailer. What’s more, our habitats are easy to park and stow in a garage during the off-season, so you won’t have to worry about storage fees. All of our trailers deliver an amazing outdoor experience, so find your ideal habitat today!