Load Deflection Relationships for Three Log-Skidder Tires

Recent cooperative studies (Burt et al. 1982, Iff et al. 1982) by the U.S. Forest Service and the National Tillage Machinery Laboratory (NTML) demonstrated the need to develop load-deflection relationships for tires used on articulated, four-wheel drive, rubbertired skidders. Load deflection curves were needed to determine such factors as rolling radius, tractive performance, and skidder stability. These curves can also be used to help loggers determine the right combination of tire size and inflation pressure for different load conditions. Earlier studies by Biller (1972) have shown that matching the proper tire size for specific load conditions would reduce many of the problems that loggers have with skidder tires. The purpose of this paper is to summarize the load of deflection results developed from these earlier studies at the NTML.