http://www.racetech.com/evalving/Spr...pringType=Fork
long link to the spring rate calc for a naked sv650 '01 (mine) follow links from the main site to alter rider weight and bike year. They worked really well on my VTR and would say they made it feel firmer but still compliant. They also recommend 15w oil and state the standard spring rate as 0.706 kg/mm out of interest.
JonC