New Tests on Polyurethane-Filled Tires Show Soft Ride Results

Enlarge Image Arnco G-Test Results

March 9, 2005 • In a recent series of accelerometer tests, Arnco, South Gate, Calif., has determined tires with polyurethane flatproofing have less than half the "G" forces of solid rubber cushion and pneumatic tires when run over 3/4-, 1-, and 1-1/2-inch obstacles. According to Arnco Technical Manager Bob Rose, the latest findings further reinforce the industry's contention that using polyurethane-filled tires results in a softer ride, proves to be less damaging to the equipment, and promotes less operator fatigue.

 

The tests were conducted at Arnco's test facility in Chattanooga, Tenn., using a John Deere 240 skid steer both with a 2,500-pound object and unloaded, and with RePneu^®- and SuperFlex^®-filled tires. RePneu is an all-purpose, heat-resistant material that has a 28 durometer softness and offers medium tire deflection and improved tear strength and compression, and SuperFlex^® flatproofing material is used when ride, footprint, and flotation are needed, as it functions similar to an air-filled tire with an 8 durometer softness.

 

The test course consisted of a 135-foot smooth concrete surface with built-in obstacles at intervals throughout the course. Accelerometers were positioned on the vehicle axles, and "G" force values were recorded on a computer hook-up -- one "G" is equivalent to 9.81 meters per second squared in acceleration. Each test was done at the same speed through the obstacle series and multiple runs were made over a five-day period using 10x16.5 heavy duty 10-ply pneumatic tires at 90, 60, and 45 psi that were first filled with air, then with SuperFlex and RePneu polyurethane. The same tests were then run using a set of solid cushion tires. All tires exhibited almost equal footprints in the loaded and unloaded models.

 

In accelerometer tests with the 2,500-pound load, the Arnco RePneu-filled tires scored 0.09, 0.11, and 0.20 "G" forces, or 59%, 64%, and 70% less than solid rubber cushion tires, when going over 3/4-, 1-, 1-1/2-inch obstacles, respectively. In tests where the skid steer was unloaded, RePneu scored 0.21, 0.36, 0.40 "G" forces, or 58%, 57%, and 61% less than solid rubber cushion tires. RePneu-filled tires also had 74%, 78%, and 77% less "G" force than pneumatic tires filled to 45 psi on the loaded skid steer, and 61% , 61%, and 67% less on the unloaded skid steer. RePneu was 71%, 85%, and 79% less loaded and 74%, 69%, and 70% less unloaded when compared to pneumatic tires filled to 80 psi. Tires filled with Arnco's SuperFlex^® flatproofing material scored 0.19, 0.21, and 0.31 "G" forces. Tests with a 2,500-pound loaded resulted in 0.26, 0.25, and 0.40 unloaded.

 

For further information, visit www.arnconet.com.