There are now 10,000 miles on Rocky, our 2017 Tiffin Allegro Open Road 32SA, but it feels more like 5000 + 5000.  I’ll try to explain:

The first 5000 miles were entirely half-day, single destination trips, since our schedules only gave us time for an occasional long weekend away from home.  In terms of the ride comfort and overall handling, I was generally pleased.  I had taken the advice of other gas chassis owners and added a couple of suspension enhancements:  front and rear Sumo Springs that cut down on side-to-side sway on uneven road surfaces; and a Safe-T-Plus steering stabilizer that, when combined with a wheel alignment, reduced steering “wander” and helped the coach track better on straight roads.  I’m also a believer in proper adjustment of the tire pressure based on weighing the fully loaded RV.  These mods and adjustments result in more precise steering, less body roll, and generally stable handling.  Combined with the relatively good condition of the roads in North Carolina, this left us satisfied with the driving experience.  

The second 5000 miles were another story entirely.  This was mostly long-distance driving through a total of 11 states between North Carolina and Colorado.  We’ve traveled these same roads in our previous motorhome (a smaller Sprinter-based RV), but the ride in Rocky was much less comfortable when we were driving at highway speeds on poorly maintained roads.  The problems are most noticeable on concrete roads and bridges with expansion joints, and also on older asphalt roads that need resurfacing.  Although Rocky’s plush seats absorb a lot of the general vibration over those segments, it’s still not pleasant to experience the jarring, bouncing, and swaying in response to rough road surfaces.  

All of this motion demands increased concentration as you focus on maintaining vehicle control; this is not only tiring for the driver, but it also takes a toll on the motorhome as well.  By the time we had traveled from North Carolina to Missouri, the freeway ride had been so rough that the front grill had broken free from three of its four mounting points and was dangling inches away from the radiator.  And before we reached Colorado, the vibrations and bouncing had sheared the four screws that keep the dashboard cover mounted to the coach frame.  This prompted us to stop in Denver to have our shock absorbers replaced with Koni FSD shocks, a popular upgrade for RV owners seeking a smoother ride. The new shocks definitely helped, but it is a relatively subtle improvement and certainly not a solution for the more violent motion that concerns me when we’re driving on roads in poor condition.

When I’ve discussed these issues with other RV owners, their most frequent response is that I should consider trading up – from our Class A gas-powered motorhome to a Class A diesel-powered motorhome.  The large diesel chassis RVs are typically equipped with an airbag suspension, which is well-known for having a smoother ride than the antiquated leaf spring-based suspension on our Ford F53 gas chassis.  But I typically dismiss this suggestion for the same reason we chose a gas chassis Class A in the first place:  a diesel motorhome with a feature set and quality comparable to ours adds about $100,000 to the retail price, and usually much more.  Unfortunately, there are no airbag suspension upgrades available for our motorhome’s gas chassis. 

All of this is to introduce what prompted me to research LiquidSpring, a company that specializes in converting a vehicle's conventional springs-and-shocks suspension to a microprocessor-controlled compressible fluid system.  They call this "Compressible Liquid Adaptive Suspension System" (CLASS), and recently they have been moving this technology into the RV world.  Motorhome magazine published an excellent article about this system, and I won’t try to repeat all the technical information here.  The key point is that this an active suspension system which is constantly monitoring the road conditions and dynamically adjusting the suspension’s spring rate, providing a softer ride on rough roads but greater control on smooth roads.  This sets it apart from other RV suspension systems – even airbags – which are passive and therefore can only be expected to respond optimally within a narrow range of road conditions.   

Many of the LiquidSpring applications have been for ambulances, where it’s easy to understand the need for a smoother ride while transporting patients and the EMTs/paramedics trying to help them.  And the company's focus on ambulances brings up the current shortcoming of the LiquidSpring system:  it is a replacement for the rear suspension only, and so it may not seem like a solution for smoothing a motorhome's ride in the front.  However, much of the action that you feel in the front of the coach is due to motion transmitted from instability around the rear axle, which is carrying most of the motorhome weight.  Stabilizing the rear should help smooth the ride up front as well as improve overall handling characteristics, including how the coach takes corners and responds to wind gusts.  Still, it is a gamble as to whether a replacement of the rear suspension will solve most of the motion problems I am currently experiencing in the front end of our motorhome.  At least we’ve already done what we can with the front suspension by upgrading the shock absorbers and installing Sumo Springs.

The other hesitation is that this is an expensive mod:  the CLASS parts alone cost about $8,000 and the installation takes several days, so the total price is around $12,000.  I can self-rationalize the need for this, since I’m convinced that we got a good deal on our motorhome purchase and we want to enjoy it for years.  Still . . . it’s a lot of additional cash for an experiment.

But I am cursed with some sort of "early adopter" syndrome, and I am excited rather than scared by solutions that employ innovative design and new technology.  So I bit the bullet and arranged with Wayne Wells at LiquidSpring to have CLASS installed at their factory in Lafayette, Indiana.  It was a long drive for me, but all it took was an hour on Indiana’s poorly maintained stretch of I-70 to remind me why I want to do this.  And the trip provided me with the opportunity to see the LiquidSpring factory (thanks to my tour guide, Chad Wilkins) and spend time talking with the CEO, Dean Bartolone, about their product and their vision for its future.  

When I write the next blog post (part 2 of this series), I’ll include some pictures that Chad will be sending so that you can see exactly what’s being done to swap out the suspension systems in our motorhome.  I’ll also relay a few things I learned during my visit to the factory.  (Spoiler alert:  LiquidSpring is actively developing an add-on kit that will replace the standard gas chassis front suspension.)  In the meantime, please send good wishes to Rocky as he gets prepped for orthopedic surgery: