When caught up in the beauty of the exterior graphics and interior appointments of a new motor home, many of us oftentimes overlook its driving aptitude. Experienced RVers will tell you that when it comes to the enjoyment you will get from your investment, one of the most important components of your coach is the chassis platform. Despite the tremendous increase in motor home sales over the past decade, RVers still typically select the exterior and interior options first and then accept the chassis that comes with the motor home they have chosen.

Barney Alexander, the instructor for the Driver Confidence Course at Lazydays, tells me that he is beginning to receive more questions from experienced RVers about the inner workings of chassis and their components. “The trend is shifting now,” says Alexander. “More of today’s RVers want to have a better understanding of the various chassis that are available and discover what all of the intricacies mean,” he continues. He says that about one-third of his students attend the course a second time to learn new RV driving techniques and begin  their pre-purchase research.

Many RV manufacturers prefer to build their homes on a chassis that they purchase from companies such as Workhorse, Freightliner, or Spartan because they are the industry’s leading chassis manufacturers. By doing so, the manufacturer can focus its efforts on building just the house. Of course some produce their own proprietary chassis platforms, while others mix it up and produce their own chassis for higher end products and purchase the platforms for other products in their lineup. Many floorplans offered by various RV manufacturers can actually be ordered on a variety of chassis from these manufacturers!
 
Wheel Cut and Wheelbase
As you research the various designs available, it is important to identify the two most critical chassis components: wheel cut and wheelbase. When combined, these two elements determine where you need to start your turn in order for the rear of your motor home to clear a corner or any obstacle alongside it. The wheel cut measurement is the angle that the wheels will turn in either direction and ranges from 45° to 60°. The higher the degree of wheel cut, the shorter the turning radius. For example, a motor home with a 55° wheel cut will turn in a smaller circle than a motor home with the same wheelbase and a 45° wheel cut.

Wheelbase, on the other hand, is measured in inches and is the distance between the center of the steer axle and the center of the drive axle, unless you have a tag axle. Then it is measured between the center of the steer axle and the midpoint between the drive and tag axles. As the length of the wheelbase increases, the amount of room you need to turn increases because the pivot point (drive axle) is further from what is actually turning it (steer axle). You can compensate for a larger wheelbase with a higher wheel cut. For example, a motor home with a 304” wheelbase and 60° wheel cut will turn in the same space as one with a 266” wheelbase and 55° wheel cut. 

According to Alexander, “New RV owners are often not aware of the role these chassis components play in the performance of the RV. Many of my students wish they had learned how wheel cut and wheelbase impact the maneuverability of their RV before they purchased because it would have shed light on the
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importance of chassis selection.” Alexander continued, “On many occasions I have had students go from my classroom directly to the dealership and trade in their RV for a model built on the chassis whose performance was more suited to them. They oftentimes purchase a shorter RV the first time around, thinking that they cannot drive something larger. When in fact, once they understand how wheel cut and wheelbase work, they discover that they can easily drive a longer one.”

Test driving the models you are considering to purchase is essential. If you plan to do 90% of your driving on the highway, you may opt for a different performance than those who tour main streets and back roads. In the latter, you will be turning more often and be more susceptible to quick braking, rapid change of direction, or moving in tighter spaces so these chassis components will be very important in your decision making process. Read on to learn more about today’s various chassis offerings.
 
Monaco
Monaco Coach Corporation offers a 50° wheel cut on all of its models and also employs out bound airbags to increase motor home stability and avoid side-to-side sway. Models with a tag axle contain ten airbags while all others have eight, with the exception of the Neptune and Cayman, which have four. Roadmaster chassis are manufactured to match the needs of the floorplan and model. Chassis range from 29,000-lb. to 50,300-lb. GVWR and boast from 7,000-lb. hitch capacity to an optional 15,000-lb. on S-Series chassis. Bob Richardson, Regional Sales Manager for Monaco, points out that “RVers like a single point of accountability, which is why Monaco builds its own Roadmaster chassis. When an order is received, the first thing built is the chassis, so a 2009 motor home always has a 2009 chassis.”
 
Country Coach
Country Coach also builds its own chassis, known as DynoMax®. Aaron Greenlee, Regional Sales Manager for Country Coach, notes, “Usually, shoppers come to Country Coach, after owning other motor homes so they really do their homework before making their decision.“ Greenlee continues, “We build about 400 coaches a year and each chassis is uniquely engineered and built for its coach as well as its specific floorplan. We also conduct significant dynamometer testing on every coach to ensure the highest quality ownership experience.” Country Coach owners appreciate the fully liftable tag axles, too. With this feature, maneuvering through tight U-turns is much easier. When all is said and done, you can drive from Florida to New Orleans and not feel worn out when you arrive.
 
American Coach
Through a relationship they have developed with Spartan, Fleetwood’s American Coach division builds all of its luxury motor coaches on the Liberty chassis. Known for its smooth ride, this platform consists of standard Spartan front and rear sections coupled with a super strong Liberty bridge beam. Ryan Rebar, District Sales Manager for Fleetwood, notes, “We partnered with Spartan Chassis along with Dexter Chassis Group to develop a chassis that would allow us to meet our customers’ growing demand for superior quality and strength. These chassis manufacturers have approximately 100 engineers who design for fire trucks, ambulances and sophisticated military vehicles, as well as motor homes, so they understand the importance of suspension, cooling and drivability.” Additionally, with its 55° wheel cut the Liberty chassis allows a 45’ tag axle motor home to maneuver more easily in and out of space restricted areas.
 
Tiffin
In Red Bay Alabama, Tiffin Motorhomes recently developed their own Powerglide chassis. Constructed with the huck bolt technology found in the heavy trucking industry, a permanent fastener system is hydraulically installed under 27,000-lbs. of pressure so it never requires tightening. In fact, the only way you can remove the chassis bolts is to cut them off. Also, in addition to incorporating a Tuthill front suspension system and custom-tuned Bilstein shocks into the platform, Tiffin’s engineers moved the fuel tank, propane tank and batteries further forward creating an even smoother ride. Tom Webber, of Tiffin’s Dealer Support Group, states, “Before attaching the house to the platform, dynamometer testing is performed on all components under typical driving conditions.” He continues, “With its 55° wheel cut and specifically-designed wheelbase options, the Powerglide chassis is a pleasure to drive.”
 
Winnebago
Designed with the help of Freightliner, Winnebago Industries offers their all new Maxum chassis on most of their higher end diesel models. This unique lower rail design allows for up to 220-c.f. of storage space, which can be further enhanced with Winnebago’s Smart Storage system. The integrated floor and framework atop the chassis provides up to seven times the strength of traditional straight rail chassis. The Maxum chassis is  currently available on the Winnebago Vectra and Itasca Horizon with independent front suspension, and on the Winnebago Tour and Itasca Ellipse with a front I-beam suspension system. The Vectra and Horizon combine a 60° wheel cut with a 267” wheelbase, while the Tour and Ellipse provide a 55° wheel cut on the same length wheelbase. As a result, all of these models provide exceptional maneuverability and a smooth ride.
 
Workhorse
If you are looking to purchase a gas powered motor home there are also many chassis options from which to choose. Workhorse Custom Chassis provides some unique component configurations in their W-series chassis designs. All come with a 50° wheel cut and wheelbase options ranging between 190” and 242”. This allows RV manufacturers to optimize handling for the length and floorplan of the coach being built. Additionally, when coupled with the only 6-speed Allison transmission available on a gas chassis, a shift energy management system allows the transmission to control the engine during shifting. As a result (under appropriate driving conditions) fifth and sixth gear overrides are selected electronically which allows the engine to run at reduced RPMs thereby maximizing fuel efficiency. These same features are available on the Workhorse UFO (Universal Floorplan Option) chassis, which is available in both gas and diesel configurations with several motor home floorplans. The UFO chassis comes with a 55° wheel cut and is offered in wheelbases ranging from 208” to 262”.

As you can see, motor home chassis aren’t just tires and steel framework. They are technological marvels capable of providing years of enjoyment. Do your homework before making your next motor home selection! And don’t forget, if you’re coming to Florida the Lazydays Driver Confidence Course is a “must.” It’s even worth planning a special trip!