The Traxxion Dynamics Shock Spring Torrington Bearing Kit for 2.50 Inch ID springs is a simple to install accessory that will make preload adjustments substantially easier. The kit consists of a flat radial roller bearing and a stainless steel shim. The bearing goes between the new shim and your stock steel shim like a sandwich. This takes away a great deal of the friction between the spring and the preload collar. This configuration requires much less effort to move the preload collar.