I noticed yesterday before I went riding that when I push down on the back of the bike, it returned slowly instead of springing back. The only reason I did this was because I was going to have a passenger for the day and was thinking of adjusting the rear spring stiffer to offset the additional weight. Is this normal?

 

Thats your shock doing it's work. Some times when you first push it down it will rebound fast then the next time you push it down it starts working like it should.