Hey folks, I have a quick headset related question. Just built up a vintage road frame with a threaded headset and have noticed that the adjustable race below the locknut is loose even though the stem and locknut are reasonably tight! Not sure what this could be although a friend suggested I needed another spacer (already have about 10mm of spacers between race and locknut) Any ideas what this is? Cheers!

Locknut's bearing down on top of the steer tube. If so a bigger spacer would help. Better to have one big spacer than a bunch of small ones, BTW.

Brilliant, that's not a big problem. I'll try and track down a larger spacer. Thanks zzyzx!

This is a threaded fork and headset right? Can you thread the top race down far enough to adjust the headset properly after loosening the lock nut? If not, the fork's steerer may not have adequate thread length to suit the headset's stack height. The only fix is to have it threaded further. A spacer will do no good if the top race runs out of thread travel.

Could be bad threads on the fork where the adjustable cup seat as well or bad threads on the adjustable cup. Is it tight before you add the spacer and lock nut?

Hmmm, haven't checked that! Won't get my tools back till Thursday so won't get a chance to until then. As far as I remember though the race did have enough purchase on the steerer but I'll need to check. Thanks for the help guys hopefully it's one of the above problems so at least I'll know what I'm dealing with! Cheers.