When choosing a new motorhome, you may be interested in knowing the pros, cons & differences between a solid axle vs IFS (independent front suspension).
While both options have advantages and disadvantages, the choice could significantly impact your motorhome’s performance, handling, and ride comfort, depending on where and how you travel.
Just as we looked at single axle vs tag axle RVs in a previous post, in this post we’re looking at key differences between a solid front axle vs IFS in motorhomes, and which suspension design might be better suited to particular styles of RV travel.
- 1) What Is a Solid Axle RV Suspension?
- 2) What Are the Advantages of a Solid Axle vs IFS Suspension On a Motorhome?
- 3) What Are the Disadvantages of a Solid Axle Suspension On a Motorhome?
- 4) What Is an Independent Front Suspension (IFS)?
- 5) What Are the Advantages of IFS for Motorhomes?
- 6) What Are the Disadvantages of IFS for Motorhomes?
- 7) How to Choose Between Solid Axle vs IFS for Your Motorhome
- 8) Free RVing Tips, Tricks, Reviews & Giveaways
What Is a Solid Axle RV Suspension?
Known for its durability and simplicity, a solid axle suspension finds both wheels on a single rigidly connected axle. This means that when one wheel encounters a bump or obstacle, the other wheel is affected as well.
Solid axle suspension systems have been common in the automotive industry for decades. When looking at the differences between IFS vs solid axle suspensions, there are several key features as well as advantages & disadvantages to consider where solid axle suspensions for motorhomes are concerned.
What Are the Advantages of a Solid Axle vs IFS Suspension On a Motorhome?
There are several benefits to having a solid axle suspension in a motorhome.
Solid axles are relatively simple overall. Solid axle motorhomes have fewer components than independent RV suspensions, so they’re easier and less expensive to maintain and repair.
Solid axles are typically more robust and less prone to damage when compared with IFS systems. They can handle heavy-duty loads, rough roads, and off-road conditions with relative ease.
Due to the geometry of their uniform suspension systems, motorhomes with solid axles often provide better stability when towing trailers or vehicles behind them.
Not all motorhomes are meant to be taken off-road, and not all motorhome owners have a desire to travel off-road. However, if you want to be able to travel off-road with your motorhome, a solid axle rig is typically better suited for rough off-road terrain. This is due to their greater ride height/ground clearance as well as their tendency to be more durable overall.
What Are the Disadvantages of a Solid Axle Suspension On a Motorhome?
Solid axle suspensions also have a couple of key disadvantages for motorhomes.
Solid axles tend to offer a stiffer ride, so the ride quality is often less comfortable for passengers in solid axle motorhomes, especially when traveling on tough terrain or uneven roads. The solid connection between the two wheels means that whatever impacts one will also impact the other. IFS is better at isolating road imperfections.
The handling can feel less precise in a motorhome that uses a solid axle suspension, especially when navigating city streets or tight corners. Keeping a solid axle rig in line to maintain lane control can also be more challenging than IFS during high-speed driving.
What Is an Independent Front Suspension (IFS)?
Independent Front Suspensions (IFS) were designed to address some of the shortcomings of solid axle trucks. IFS is becoming more popular in the motorhome industry due in part to its improved ride comfort and handling characteristics.
The main difference between an independent front suspension vs a solid axle suspension is that with an IFS, (as the name implies) each front wheel has its own separate suspension system. This allows each wheel to move independently of the other.
What Are the Advantages of IFS for Motorhomes?
There are several key advantages of independent front suspensions for motorhomes.
Improved Ride Comfort
Because each wheel on an IFS can react independently to bumps and imperfections in the road, an independent front suspension provides a smoother, more comfortable ride. The right wheel hitting a pothole won’t directly transfer the jolt to the left wheel, keeping things less bumpy.
A motorhome that’s equipped with IFS typically provides better handling, traction, and overall maneuverability. This makes motorhomes with IFS easier to drive around corners and tight spaces and safer due to greater overall stability.
All of this is due to the ability of each wheel to address imperfections in the road without being affected by the other wheel on the same “axle.” This transfers less impact to the chassis when hitting bumps and enables the wheels/tires to maintain better contact with the road.
While many IFS setups have a greater wheel cut than a solid axle and seem to track better, the actual difference in wheel cut is pretty minimal, typically only about 5 degrees.
IFS systems tend to be lighter than solid axle suspensions which means better fuel efficiency and improved weight distribution. Since the front end of a motorhome is more likely to be close to the maximum axle weight than the rear, keeping the front-end weight down is a big help.
Less Noise and Vibration
An IFS tends to offer a quieter and more pleasant driving experience overall due to better isolation between the front wheels. That means less noise and vibration in the cabin.
What Are the Disadvantages of IFS for Motorhomes?
There are also a few disadvantages to independent front suspensions for motorhomes.
Due to the complexity of an IFS, motorhomes with independent front suspensions are more expensive to buy and maintain.
An IFS has more moving parts than a solid axle suspension, so there are more potential failure points. For example, while a solid axle suspension might have 6-8 moving parts, an IFS could have more than 20.
IFS components tend to be more vulnerable to damage in certain off-road or rough-road conditions. And the cost to repair damage to an RV independent suspension is usually higher. That said, most large motorhomes aren’t doing a lot of serious off-roading.
Depending on the design and engineering of the specific motorhome, towing stability can be somewhat compromised with IFS vs solid axles front and rear. IFS may be considered higher-end, but that doesn’t mean everything about it is superior to a solid axle.
How to Choose Between Solid Axle vs IFS for Your Motorhome
The choice between solid axle vs IFS for your motorhome will depend on your specific needs and preferences as well as your typical style of travel. And of course, there may be other considerations (floorplan for example) that lead you to place solid axle vs IFS lower on your list of must-haves.
A solid axle suspension may be the better choice if you tend to travel off-road and are concerned with durability and towing stability. However, if your priorities are a comfortable ride, smooth handling, and a more refined driving experience overall, you may be more satisfied with an IFS.
Note that on motorhomes equipped with air-ride suspensions (i.e. diesel pushers), the ride improvements of IFS aren’t necessarily as evident due to the improvement air suspension itself provides.
In truth, in most cases, you may not really have much choice. The suspension of a particular motorhome that you want will be what it will be. A particular year, make, and model of motorhome is going to come with one type of suspension or the other. Most often the choice made by the manufacturer will come down to suitability and cost.
In the discussion of solid axle vs IFS, we find that both choices have their benefits and their drawbacks. Your personal needs and preferences as well as your budget and the type of traveling you tend to do (i.e. smooth or rough terrain) will be the most significant factors. But the reality is that the type of motorhome you want to buy is already equipped with one type or the other.
But if solid axle vs IFS is important to you, you’ll want to include the pros and cons of each in your decision-making process, the same as so many other factors when buying an RV.
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