Long time ago I had my lbs install a stem for me on my previous bike. I saw the mechanic check for play and then check for noise by lifting the front wheel slightly and dropping it. I changed stems a few times after to that bike with no issues. (preload, check for play, tighten stem bolts) I'm having issues installing a new headset on my new bike, also aluminum. Although I can't feel any play, I do hear some knocking when I lift the front feel and release it. I can't recall this with the original headset. Is this normal. Spacing from stem to steer tube seems appropriate and everything is torqued to specs. I have not ridden it after installation. Any thoughts? Thanks and I did try the search function!