The air caps in our old bikes used to be set with no pressure in them at all. We used to stand the bike up with no rider and expell all the air from the cap. But if you find this too soft (compression) pump a small amount into it. Carefully. 1 or 2 pounds. Bottom screws are rebound. Turn the screw all the way (carefully) untill the clicks stop. Then turn the oppisite way counting the clicks to the end. Halve the number and set there for a starting point. Adjust either way to suit. Or you could get really serious...