Case Construction Equipment has launched the "Flex-Frame" maneuverability system for its 400B series backhoe loaders, targeting municipal road maintenance crews operating in congested urban environments. In single-lane road rehabilitation, traditional backhoe loaders struggle with tight turns. The fixed wheelbase forces operators to make multi-point turns, dragging the rear tires sideways (scrubbing), which rapidly wears tires and tears up the freshly laid asphalt base course.
The Flex-Frame system introduces a "Hydraulically Variable Rear Track" (wheelbase). The engineering innovation is the "On-the-Fly Track Extension." When the operator engages the rear stabilizers to dig, the track is standard. However, when driving in tight urban confines, the operator can command the rear axle to physically slide outward hydraulically by 300 millimeters on each side, widening the rear track by 600mm. This drastically lowers the center of gravity for highway transport and increases the turning moment arm.
Furthermore, the system features "Predictive Trajectory Rear-Steer." Instead of a rigid trailing axle, the rear wheels are equipped with electronic steering cylinders. The ECU monitors the front steer angle and articulation of the tractor unit. Using a kinematic model, the system actively steers the rear wheels to follow the exact path of the front tires (zero-scrub trajectory). When making a 90-degree turn in a narrow lane, the rear wheels automatically counter-steer inward, allowing the machine to pivot within its own length without the rear tires ever dragging across the pavement. This smart chassis architecture reduces tire replacement intervals by 45% and eliminates the need for constant machine repositioning on tight job sites.
