Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 22 Post(s)
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Most, if not all, expanding plugs separate the function of expanding and wedging in the fork from the adjustment of the top cap. Typically the top of the plug takes a fairly large hex key to expand and lock it, then the 6mm top cap screw is threaded into the locked plug.
If the headset isn't adjusting, the most common causes are,
1- fork too long, and top cap beaching on the top of the steerer.
2- stem not free to slide down, (forgot to loosen?) or some other obstruction
3- expander not tight and getting drawn up by top cap screw
4- centering cone missing from stack, or bottom of the stem resting on bearing top cover, rather than the cone. This is critical, as some cones sit very low above the headset and require a small OD spacer above to keep the stem from touching the bearing cover.
5- upper bearing inverted.
There are other possibilities, but this is for starters.
I suggest you, pull the top stack apart, down to the upper bearing, and reassemble it in sequence, making sure that you have a continuous, uninterrupted line from the lip of the top cap, down to the centering cone of the bearing, so that the cap can press the cone without anything getting in the way.
I suggest, you pull it
An ounce of diagnosis is worth a pound of cure.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
“One accurate measurement is worth a thousand expert opinions”
- Adm Grace Murray Hopper - USN
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