A scalable high-performance bouncing apparatus provides convenient access to untensioned internally semi-mounted springs/tension elements. A holster retains the inoperative semi-mounted elements and avoids contact or friction with fully engaged tension elements. Adjustable connection elements permit compensation for lengthening of spring elements due to creep or elongation set. The connection elements include collars that compress the tension elements, and may be connected to the springs/tension elements by first stretching the elements beyond their working elongation and then placing the collars onto the stretched portions.