I made some fork damper improvement tests. With used stock components and 20 wt oil you can pull the damper rod up by hand in about 3 seconds. With a new top cap and the cup flaired to .680″ you can pull up the damper rod in about 5 seconds. With a new top cap and the cup flaired to .685″ you can pull up the damper rod in about 9 seconds. Those are significant improvements. The top cap should be sleeved with brass tubing as shown at: https://jsmotorsport.com/js-motorsport-technicalmore-norton-fork-upgrades/ The brass tubing tightens the clearance at the damper rod and provides longer life.