A secondary ascender system for use in rope climbing and with other rope climbing systems that provides a knee ascender permitting full range of motion and energy capture from two legs by encasing an interior portion of the length of an elastic cord used for tending the knee ascender within a load bearing member. The load bearing member connects a foot attachment to an ascender and transfers loads applied to the foot attachment and via the elastic cord during tending to the ascender to advance up the rope.