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!

You need to give more detail, specifically are you using a Headset (threaded steerer tube, quill stem) of AHeadset (threadless steerer), as they are quite different in setup.

First, take off the top cap and see if the steerer tube is flush with the stem. My guess is that the clamp area on the new stem is a little narrower than previous stems and you are not getting the right preload because the cap is against the steerer tube. If this is the case, just add a small spacer under the stem and adjust.

I actually had this issue with my previous bike once and did exactly what you are suggesting. I'm pretty sure I have approx. 2-3mm distance from the top of the steer tube to the stem. Thanks...any other suggestions?

One thing that I did notice and maybe helps diagnosing the problem is that when I loosen the stem screws the bottom one is much more difficult to loosen that the top one. They are torqued to the same specs. It's a Ritchey Pro stem by the way. Maybe it's the front wheel hub, or ??

First, I'd remove the cap and check instead of being "pretty sure". Assuming the stem is above the steerer, I'd straddle the bike, lock the front brake and rock the bike forward and backward. This is a much better than the "drop test" to check for a loose headset. If it is knocking, you don't have adequate preload. It is pretty easy to feel where the knocking is using this method.

Thanks so much for your help. So I just checked, the stem is above the steering. I can't feel any knocking when I straddle and rock the bike. I started playing around with different preloads by tightening the cap screw by so much more each time I reinstalled the stem. I could feel/hear less noticeable knocking as I applied more torque to the cap, but I'm afraid to damage the star nut. Thoughts?

If everythings correct, you won't stress the star nut enough (to damage it) to get the proper preload. Be sure the crown race, or in the case of cartridge bearings (crown ring) is fully and squarely seated on the fork crown. Be certain the bearing cups are square and fully seated in the head tube. If everything is proper the preload adjustment using the top cap and star nut requires very little force.

You do have the compression ring above the top bearing, right?

Thanks for your reply! I'll verify this when I get home from work and let you know how it went.

Sorry for the late reply. Although the headset was a tad loose, the main issue was that the front skewer was not tight enough! I did not check it before, because I assumed that the lbs had properly tightened it. Thanks for the help everyone.

That was going to be my guess. Also, a loose front skewer can result in your front wheel falling off and you smashing your face gainst the pavement. You should check it periodically (like, say, every time you put air in your tires). They generally don't loosen on their own but sometimes tricksters can get at your bike when it is locked up, or it wasn't tightened properly during the last maintenance. Disk brakes have also been found to cause QR loosening over time.