The Future in Concaves is Here

“After our period of testing, it appears that the future may be here, and we want to be there with it,” Tribine VP of Engineering Bob Matousek stated about KX7 concaves.

The period of testing he’s referring to is a 10-day, side-by-side comparison between KX7 and OEM concaves. Central Kansas farmer and engineer Darren Nelson volunteered 1,000 acres of wheat for testing, which was conducted on his familiar 7088 platform to filter unknowns out of testing. According to Matousek, the conditions were ideal. “Darren is a fantastic engineer and an even better farmer,” he noted. Combining a favorable growing season with his knowledge in producing very large yields. In fact, Nelson was named central region winner of Kansas Wheat’s 2015 Yield Contest, with yields exceeding 108 bushels per acre.

Matousek is renowned by agricultural engineers for his numerous combine innovations. Beyond his recent involvement in launching Tribine, he was a key member in patenting many components in modern rotary combines and has led several combine research and development efforts.

“After years of experience, I’ve learned that whenever yields are high, you get kind of nervous as the combine guy,” said Matousek. “A lot of grain is going through the combine, and a lot of grain is being asked to go through the concaves.” In other words, the high yields were perfect for putting concaves to the test.

The KX7 philosophy, Take Control of Your Harvest, was quickly put into play. Day one showed good results, but a few factors could have been better. Throughput was improved about 15% using KX7 compared to traditional concaves; however, this higher efficiency rate drove machine losses to 0.5%. While the loss was still considered very good (1 – 3% losses are very common when scientifically measured), Nelson’s OEM concaves were dialed in to show only 0.3% loss. The KX7 installation was reviewed and adjusted for the remainder of the test.

“I didn’t necessarily believe in the configuration that was installed; I thought we had shorted the separation a little bit,” said Matousek. To improve separation, the team swapped six of the MaxThresh boxes for MaxRound boxes. They left MaxThresh on the right side, where the crop came in off the top cage, and kept the rest of configuration with MaxRound boxes. In some cases, this created a mix of MaxThresh and MaxRound boxes in a single concave assembly. The result was an immediate drop in rotor loss.

“We saw stellar performance once reconfigured,” said Matousek. “Losses were about 0.1 to 0.25% for the remainder of the test period. In fact, the last day of testing, we literally had only a few kernels of loss.”

KX7 and Matousek will continue their efforts to offer a premium concave as standard equipment in Tribine combines. Additional testing in soybeans and milo is slated for fall. As for Nelson, we can assume from his comments that he’ll be along for the ride. “The combine seemed a whole lot more relaxed, and it was a good deal of fun,” he said.


KX7 concaves are available for several Case IH, Challenger, Gleaner, John Deere, and Massey Ferguson combines. Visit our Models page to learn more.