Noleen ATS Comp 26 Front Fork Shocks - Oil Needed?
Bikes that sold in the price range of the Zed were sold with very simple front suspensions. The forks consist of a spring (sometimes only on one side), some type of plastic slide or bushing and some rubber bumpers on the end of the springs. Very few service parts, if any are available. There is no rebound adjustment (this is the rate that the fork extends after compression). The preload adjustment is done by tightening a long bolt that passes thru the spring and shortens the spring as the bolt is tightened. The usual cause of failure is rust on the uppers or the plastic bushings wearing out. If you have completely disassembled ,cleaned and relubed both sides it is likely as good as it going to get.