knight_ripper, first off I don't know if the OEM front are re-valveable / re-buildable. The rear is. Often times when a re-valve is being done the spring(s) are replaced too, they are seperate processes. The OEM front spring is a special progressive spring I don't know of any direct replacements for them. The rear spring is replaceable, needs to be done if a swing arm length change has been made, of if the rider is of greater weight than what the bike was originally designed / set up for. If you need a new replacement rear spring I offer those to members for $50 plus shipping, and they are available in several rates.