Originally Posted by
HillRider
Take off the top cap and look to see if the steerer is at leas a couple of mm below the top of the stem. If the steerer is flush, you cannot adjust the headset. Either add another spacer under or above the stem.
+100
99% percent of the time that a headset doesn't adjust, it's because the top cap is bottomed against the top of the steerer and cannot push the stem or spacers lower to set the bearing.