The Kelderman Story

Realizing the need for a better ride on buses and chassis cab trucks, Kelderman has spent years developing a cost-effective solution to reduce the shock and vibration to the bus body.


Founded in 1970 as a highly innovative manufacturer of agricultural products including rubber track systems, corn harvesting attachments, and hay raking equipment, Kelderman has been considered a leading innovator in the agricultural and automotive industries for over 50 years. 

In 1990, founder Gary Kelderman and his son Jeff shifted focus as Gary began developing the Kelderman Two-Stage Rear Air Suspension, a design still in production today. Over the next 25 years, Kelderman developed additional air suspension designs for buses, pickup trucks, chassis cab trucks, RVs, trailers, and even full air suspension lift kits and has become a preferred choice of bus and truck manufacturers nationwide.

In 2013, Kelderman added Rich Ludvigsen to the team.  His mission:  to market the two-stage suspension to the bus, limo, and RV markets.  Since that time, the awareness of this superior suspension has increased substantially when it comes to air ride suspensions.  Numerous states have added Kelderman to their approved suppliers list, based on performance and effectiveness of their system, in addition to cost effectiveness.  

“Simplicity, integrity, and high quality have vaulted sales to new levels,” Ludvigsen said. “Kelderman’s history and customer service keeps Kelderman at the head of the class.  Beautifully powder coated and sporting a three-year, 100,000-mile warranty are just a few reasons to consider a Kelderman two-stage air ride suspension on their shuttle buses.” 

“It’s just super simple design, and people like that,” Jeff Kelderman explained. “Technology is great for certain things, but we don’t need to have crazy technology on a shuttle bus. We need something that is reliable and if it goes down, it is piece of cake to fix.”

Proven Reliable

With suspension kits available for about $4,000, the company’s air suspension systems boast lower maintenance expenses and extension of overall vehicle lifespan.

The two-stage suspension attaches to the back of the rear leaf springs, allowing the rear springs to stay in place and maintain the stability they provide. The driver side and passengers’ side frame rails act as one, helping to maintain roll resistance and stable handling during high-speed turns.

The two-stage system has only two wear points. According to Kelderman, suspensions that completely replace the springs have several more wear points, resulting in higher maintenance costs.

A sealed compressor/dryer, sensor and a relay are included in the suspension kit and, according to Kelderman, have fewer components than competing air kits and cost less to maintain.

“Just having an air suspension itself is a lot better than the rigid springs stock suspension,” he said. “And the technology is that a simple height sensor tells the compressor when to add or subtract air. It’s that simple.”

According to Utility Bodywerks General Manager Keith Grupp, Utility Bodywerks installs over 20 Kelderman air suspension systems a month. This accounts for nearly half of the company’s overall suspension installations. Grupp said that when it comes to installation, collaboration between Utility Bodywerks and Kelderman comes into play. Any issues that may arise are quickly solved through collaboration between Utility Bodywerks technicians and Kelderman engineering staff. 

“It’s a good collaborative effort,” Grupp said. “We’ve installed thousands of suspensions and received hardly any service calls. They are a quality product throughout their lifetime. That’s just credit to the quality and design of the Kelderman systems.”

In 2003 Utility Bodywerks began offering installations of Kelderman air suspension systems as an accessory upgrade available for small and midsized buses. 

Grupp said, as the demand for air suspension systems quickly grew, so too grew the relationship between Kelderman and Utility Bodywerks.

“We went from initially offering the Kelderman suspension as an accessory, to now installing hundreds of suspensions a year for the bus and the ambulance market,” Grupp said.