We have been testing prototype Koni shock absorbers for the last two years. Yes, I mean testing. We didn’t pay for our prototype Koni shock absorbers. We are testing our new Koni shock absorbers against our previous Koni shock absorbers. Our new Koni shock absorbers are excellent. In October 2023, after returning from Alaska, Koni gave us some new prototype shock absorbers to replace our several-year-old Koni shock absorbers.
To the best of our knowledge, we were the first retail customers to have these new Koni shock absorbers. I use the term customer loosely because we didn’t pay for our prototype Koni shock absorbers (only the installation). I recognize that we already had Koni shock absorbers, so we were already customers.
Our background
Our becoming Koni shock absorber testers started in 2018, two years before we even owned our 2008 Tiffin Bus. That is when we sat through a discussion by Robert from Henderson’s Line-Up at the Coos Bay FMCA rally. During the lecture, I could tell that Robert Henderson knew what he was talking about, and his answers seemed very straightforward. Unlike some of the unfounded claims on the internet, Robert acknowledged that fixing our poor riding (at that time on a Ford chassis) was an incremental process of changes and evaluations. There isn’t one fix-it-forever-good-for-everyone solution.
Unlike many of the RVers we met, our Ford already had some incremental fixes done before we purchased it. There were some other more significant fixes we didn’t want to undertake then, which may have helped.
Testing Koni shock absorbers
Even though we knew about Henderson’s Line-Up, we were not yet customers; we kept in touch with Robert and his son, Tommy. A few years later, getting to know the Hendersons paid off. I had been discussing the suspension issues with Tommy since about 2021. Each time we visited Grants Pass in 2022, our RV got better and better, but we both knew it could be better.
About Ride Quality
Getting an independent front suspension was a selling point for our vintage 2008 Tiffin bus. Our 2013 Tiffin on a Ford chassis is more related to a school bus than our 2008 Tiffin bus. The most exciting ride was in the back row when I rode on a school bus. Sadly, the ride in our 2013 Tiffin was very similar in quality to my school bus’s rides. Instead of fixing our 2013 Tiffin, we decided to give in to diesel envy and go with a 2008 Tiffin Bus. The ride quality improved immediately. The ride in our Ford chassis RV was harsh, but our 2008 ride was best described as floaty.
One of the reasons we ended up getting our diesel pusher motorhome was ride quality. I called it diesel-envy. The springs on our diesel motor homes are based on compressed air, whereas our old RV springs were steel leaf springs and solid axles. Unlike our 2008 Tiffin Bus, our 2013 Tiffin had steel leaf springs. Steel leaf springs were first installed on wagons in the mid-17th century. In 1908, shock absorbers were created to help the springs by dampening the oscillations.
What is dampening?
A spring tends to continue to rebound again and again after being disturbed until, eventually, the movement stops. Shock absorbers limit the number of rebounds a spring makes by converting the kinetic energy of the shock into another form of energy (typically heat), which is then dissipated.
Springs and shock absorbers
Springs and shock absorbers work together to smooth out the ride. Springs absorb the bump, and shock absorbers help the spring return to its original position and be ready to absorb the next bump. Before the invention of shock absorbers, springs would keep “springing” until gradually the oscillation quit. Shock absorbers remove the oscillation much quicker than springs without shock absorbers.
In October 2022, we visited Henderson’s Line-Up for a tune-up for our suspension before going to Alaska (9 months before). Even though the ride was much better than our Ford chassis RV, I knew the ride in our Tiffin Bus wasn’t as good as it could be. The results of our improvements were obvious on our trip to Alaska, and this visit to Henderson’s Line-Up created the groundwork for us to be Koni shock absorber test pilots.
During our visit in 2022, we installed Supersteer motion control units and a Safety-Plus steering stabilizer. Supersteer motion control units help the spring respond to a vertical disturbance when you hit a bump, and the Supersteer steering stabilizer helps recenter the steering wheel after a (lateral) disturbance. They both work great. I cover that story in this article. Get the bounce-out
Another thing we did during our pre-Alaska visit to Hendersons was to tighten our adjustable Koni shock absorbers to their stiffest position. We made this adjustment because the dampening was insufficient—insufficient dampening results in porpoising.
Porpoising
Tommy took the information about how our coach was riding and our adjustments to our coach to Koni, and Koni developed their new line of shock absorbers with RVs like ours in mind. What Koni needed was a shorter travel, stiffer shock absorber that would make independent front suspension RVs like ours better than could be obtained using any available products. As part of this development and only using the feedback we gave to Koni, they set us up with their new line of Koni shock absorbers before they were offered for sale to the general public.
Suspension and ride quality
Independent front suspension
When looking for a better RV, we wanted an independent front suspension. This is because when you drive over a bump with one wheel, it does not directly affect the other wheel. Our Ford-based chassis did not have independent front suspension.
Pneumatic suspension
Unlike our Ford chassis, which had springs based on steel leaf springs, our new 2008 Tiffin bus springs were based on compressed air. Air suspension means that our springs are similar to balloons. The spring action was based on the air absorbing the bump and compressing, then rebounding. To help the pneumatic suspension, we installed Supersteer motion control units ( flow restrictors) at each airbag to limit the speed at which the air in the suspension could escape. Again, I cover that story in this article. Get the bounce-out
Shock absorbers
To keep the springs from rebounding numerous times, our Koni shock absorbers, using fluid dynamics, transfer some of the bump force into heat energy, thus preventing innumerable bounces for each bump. Our old adjustable Koni shock absorbers could not avert multiple bounces, although the ride was better after Tommy adjusted the shock absorbers to full strength. Our new prototype Koni shock absorbers are tuned to our limited travel front suspension and do a much better job at limiting the motion of the springs.
Koni shock absorbers for our independent front suspension
Independent front suspension systems are more challenging to dampen than traditional suspensions. This is because the shock absorber for each wheel needs to do the entire job for that wheel. It doesn’t get any assistance from the other wheel on the axle. Our independent front suspension design also puts the shock absorber away from the wheel and closer to the frame.
This means the shock absorber only moves a short distance when doing its job. For our RV, given the weight, standard shock absorbers were not up to the task, and we had to get these prototype Koni shock absorbers to make the shock absorbers more capable of doing their job. Even a few years ago, these Koni shock absorbers were not available.
In this video, you might say that I am a little stiff.
Here is a copy of the YouTube video made at Henderson’s Line-Up describing the effect of my new Koni shock absorbers.
Sway and steering components
This year, while at Hendersons, we replaced a drag link (one of the steering components) and the steering gearbox. Both were worn and created lots of extra steering wheel movement before any reaction in the tires. We knew these components were worn beyond limits before getting our Koni shock absorbers. Now that we have all these components, our RV drives and rides are much better.
Please subscribe and join us on our journey.
We will add you to our email list and send you updates once a week. Here is a link. Subscribe
About our links
As you know, our blog income is zero, which allows us to be independent and tell the truth. We do not get income or commissions. No, we don’t make paid endorsements. We don’t make recommendations; instead, we will tell you what we like (or dislike). The links are only provided as a quick reference to help our readers.
Links
Koni shock absorbers for our independent front suspension.
Family Motor Coach Association
SuperSteer Motion Control Units
About Comments
We love seeing your comments, but they are not automatic. I get about twenty spam comments every day, and thus, I have to turn off automatic comments. I read and then publish every comment personally to protect the blog and keep it on the subject and real. So this means that you will not see your comment right after you hit submit. Sorry for the delay in publishing your comments. Please know that we would love to hear from you.
I enjoy your work and appreciate it for all the helpful blog posts.