The springs keep the fork at a certain height but don't affect compression dampening because the heavier rider balances the force from the heavier spring resulting in no net effect and how fast or slow the fork compresses. If I increase the spring rate, the rebound IS effected because the forces at play are the from the springs and the friction of the compression dampening and the forks will rebound faster. If I counter that with thicker oil, that might fix the rebound but the compression dampening might be too harsh as a result.
Basically I'm wondering if there is a way to adjust the rebound or compression separately (I can either use heavier oil and decrease compression slightly or use the same oil and increase rebound slightly, to compensate for the stiffer springs). I'm going to try and call marzocchi about the spring aplicability and I'll post my findings, haha i can even ask about the rebound and compression!
Buf if anyone has some insight...