Designed for performance-oriented twin shock bikes Features piggyback reservoirs, high-pressure gas charge and deflective disc-valving, all packaged in a mono-tube style body Includes progressive rate springs The threaded pre-load adjustment and external compression adjustment knob allow for fine tuning to provide optimum performance rider weight or riding style Before purchasing or attempting to install shocks that are different than the OEM length, confirm that your wheel travel can be altered without causing clearance issues, such as swingarm/axle to exhaust contact as well as chain/belt guard or tire contact.. SHOCK 970 DYNA 13.5 BLK