The Komatsu 931XC has low ground pressure and good stability for steep terrain and soft ground.
Komatsu has paid much attention to stability during the design process. Komatsu indicate that with the 931XC, they have approached eight wheels differently to other manufacturers. The harvester is built around Komatsu's proven chassis concept with an articulated joint and swing axle, a tilt function for the crane and cab, and Komatsu's load-sensing stabilizer. In addition to the swinging rear axle, the Komatsu 931XC has a bogie that is mounted on the swing axle. The new suspended bogie improves stability and has improved ground contact and a lower centre of gravity.
The central position of the crane along with a tilt function shifts the centre of gravity toward the centre to ensure that the machine's weight is evenly distributed over all eight wheels. The 931XC is the lightest harvester in its class, allowing it to work effectively on soft ground. The design improves the handling characteristics as the machine follows irregularities in the terrain.
The 931XC's cab has increased space across all cab dimensions. Ergonomic improvements have been made to the climate control system and upward and downward visibility due to the front windshield design. Several different hand controllers are available as well as the industry's first remote-controlled keyless system.
Komatsu's three-pump hydraulics allows the operator to perform several tasks at the same time and maintain higher production with reduced consumption. The Komatsu 931XC uses a Stage IV Final engine that delivers 21 tons (187 kN) of traction. Interaction between the engine, control system, and transmission enables the hydrostatic power-optimized transmission to fully utilize engine power, providing advantages on steep inclines and in difficult terrain. Source: http://www.komatsuforest.com/default.aspx?id=1848&newsid=148815