Riding on Air: A Primer on Kelderman Suspension Systems

A Q&A With Kasey Sutherland of Kelderman Mfg

Looking for a smoother, more sophisticated ride for your truck camper rig? Then you’ll want to take a serious look at the top-notch air ride suspension systems offered by Kelderman Manufacturing. To learn more about their high-quality products, we recently spoke with Kasey Sutherland, the company’s director of marketing.

TCA: Thanks, Kasey, for taking the time to talk with Truck Camper Adventure. How long has Kelderman Manufacturing been in business and where is your headquarters located?

Kasey: Kelderman Manufacturing has been in business since 1970. We are headquartered in Oskaloosa, Iowa.

TCA: How did your business start?

Kasey: Kelderman actually started out as a small agricultural company. We are still involved with many agricultural projects today, but our founder, Gary Kelderman, helped design the rubber track systems used on many combine and farm tractors today. We still hold the patent for that product as well. We work closely with the Department of Energy and other Agriculture firms on many high-level agricultural projects.

TCA: What products do you make for 3/4-ton and larger trucks?

Kasey: We are known for our air suspension systems, but have recently launched our own line of off-road bumpers and grilles for late-model, 3/4-ton and larger trucks. All products can be found at www.kelderman.com

TCA: Are all of your products made here in the USA?

Kasey: Yes. We have a full manufacturing facility and all products are laser cut, hand welded and shipped from Iowa.

TCA: What is your signature product? What product put Kelderman on the map?

Kasey: On the automotive side, our ‘2-Stage Rear Air Suspension’ was our first big introduction. We developed the product in 1990 when Gary Kelderman purchased a Dodge Cummins truck and was not satisfied with the ride quality. He parked it and searched for a solution and the 2-Stage Rear Air Suspension design was born. This is something still produced today and has been adapted to all kinds of pickup trucks and chassis cab applications to provide a smoother ride quality.

TCA: Lots of companies make air bag systems for trucks. What sets your air ride systems apart from the rest?

Kasey: The Kelderman air ride is not to be confused with just adding air bags between the axle and the frame. Air bags are merely helper springs to correct rear sag and to provide additional weight carrying capacity. They do nothing for the ride qualities of the vehicle and in many situations degrades the ride. You lose nothing with Kelderman air ride systems. The main thing you gain with the Kelderman air ride is comfort.

What also makes us different is our experience. We are a family owned and operated company that has close to 50 years of manufacturing experience. We have done projects in both the agricultural and automotive industries and understand what sort of quality product is required in those fields. We honestly pride ourselves on just being the same type of person on the other side of the phone or computer screen that’s looking at our products. We get up and go to work like everyone else and we use all kinds of trucks and trailers to go camping, hunting, ride ATV’s on the weekend, etc. We’re just lucky enough to do something fun for a living and we get to make and offer a product that people really enjoy. We’re a bunch of truck guys that get to work with trucks for a living and we don’t take it for granted.

TCA: We recently published an article on the Kelderman air ride suspension system used in the EarthRoamer. Can you tell us more about your 4-link rear axle air ride system and how it works?

Kasey: The 4-Link Rear Air Suspension is designed to provide the vehicle with both a higher carrying/load capacity, as well as an improved ride quality. The design completely eliminates the factory leaf spring suspension which typically provides a harsh ride. The kit includes adjustable trailing arms which prevent wheel hop and axle wrap in heavy towing and high horsepower applications historically. We also provide an adjustable panhard bar and an upgraded/larger sway bar to help with the weight of the camper body, heavy towing, etc. When equipped with one of our air control systems, the suspension will automatically adjust to weight in order to maintain the same ride height. This means no squatting under towing. Front and rear systems combined with air controls actually allow the unit to adjust at each corner to level out at camp sites, lower the vehicle for easier entry, etc.

TCA: Can you explain how your two-stage front axle air ride system works?

Kasey: This is a fairly straightforward design. On the solid axle trucks, the coil springs are removed and we replace them with upper and lower air bag mounting brackets, industrial strength airbags, and adjustable shocks. This provides a better ride quality, front and rear ride height adjustment, and prevents the nose from ‘drooping’ under the weight of aftermarket bumpers, winches, snow plows, etc.

TCA: What is the net weight gain (or loss) installing the 4-link rear and 2-stage front air ride systems to a standard 3-4-ton or one-ton pickup truck?

Kasey: The truck will end up slightly heavier because you’re installing more parts than are removed. You’ll also have the added weight of the air control system (compressor, tank, height control valves, etc.). Most trucks end up 100-200 pounds heavier depending on the configuration.

TCA: That increase isn’t too bad. How are the pressures in your air bags controlled?

Kasey: Kits are sold with ‘manual fill’ packages where you only receive air line and Schrader valves to inflate the system. This is just like how you would inflate a tire on the vehicle. We offer control packages that typically maintain the proper height/pressure of the airbag via an electronic sensor or a mechanical height control valve. This makes it fully automated in most applications.

TCA: Do all of your systems provide three pre-set ride levels like the EarthRoamer?

Kasey: Yes, depending on the air control system. We have simple control packages that eliminate any driver input and just take care of themselves, but we do have systems that allow for full driver adjustment, programmed height settings, and more.

TCA: Who makes the air springs used in your air systems?

Kasey: We use air springs from the Firestone Industrial line. These are not automotive bags and are similar to what you would see in a tractor-trailer configuration.

TCA: For a one-ton SRW truck, which system would be more appropriate for the rear axle, your basic 2-stage system or your more elaborate 4-link system?

Kasey: The 2-Stage or 4-Link question is answered on how you use the truck. If you’re just interested in a ride quality solution, the 2-Stage kit is probably all that you need. If you’re looking for a little bit of everything (ride quality, load leveling, up and down adjustment, etc.) then you’re better suited to the 4-Link.

TCA: What onboard air system do you recommend using with your air ride products?

Kasey: Recommended air control packages vary depending on how a customer would want to use the air suspension or the vehicle. We have a variety of control packages to fit a customer’s wants.

TCA: What shocks and sway bars do you recommend using with your air ride suspension systems?

Kasey: Our systems include upgraded Roadmaster sway bars. Shock applications vary depending on the use of the vehicle. The majority of our ‘stock height’ air suspension systems use Rancho 9000 adjustable shocks. We also offer Fox shock systems (typically on lift kits) and occasionally King Shocks (like those found on the EarthRoamer).

TCA: How long does it take to install the 4-link rear and two-stage front air ride systems? Could anyone handy with tools do it?

Kasey: Installation times vary on the truck (Ford vs. Ram, Pickup Truck (F-250 or F-350) vs. Chassis Cab (F-450 or F-550), bare chassis, etc. This is typically a pretty involved installation that is typically handled by trained professionals at an off-road shop or something similar. We do have customers who install their own products from time-to-time, but most are done by other shops. A standard installation of a front and rear air suspension system with electronic, self-leveling air controls is usually in the 20-24 hour range for installation.

TCA: If one of our readers wanted to mimic the suspension system used in an EarthRoamer, what would it cost to install it on a one-ton pickup at your main facility?

Kasey: You would likely be looking in the range of $8,300 for the parts portion (front air suspension, rear air suspension, air control system). This would put an ‘out-the-door-price’ from our facility in the $11,000 range. However, this does vary on several factors as I mentioned.

TCA: Excellent! Thanks, Kasey, for taking the time to talk with us.

Kasey: Thanks, Mike! It was my pleasure.

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About Mello Mike 494 Articles
Mello Mike is an Arizona native, author, and the founder of Truck Camper Adventure. He's been RV'ing since 2002, is a certified RVIA Level 1 RV Technician, and has restored several Airstreams. He currently owns a 2016 Northstar Laredo truck camper hauled on a diesel-powered Ram 3500 pickup truck. He enjoys history, football, music, hiking, travel, and photography. He retired from the U.S. Navy in 2004 as a CWO3 after 24 years, worked in project management, and now runs Truck Camper Adventure full-time. He also does some RV consulting, repairs, and inspections on the side.

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