A flexible header for an agricultural vehicle including a frame, at least one cutter bar movably coupled to the frame, and an adjustment system coupled to the frame and the at least one cutter bar. The adjustment system is configured to adjust a position of the at least one cutter bar. The adjustment system includes at least one linkage assembly. The linkage assembly includes a first link member and a second link member. Each of the first and second link members are rotationally coupled to the frame. The adjustment system also includes at least one fluid spring coupled to the first link member and the second link member such that the at least one linkage assembly translates a substantially linear movement of the at least one fluid spring to adjust the at least one cutter bar.
