Originally Posted by
reddog3
Sounds as if something is causing binding when the wheel is installed. First thing I'd check is locknut spacing. Too long or too short which either spreads or compresses the fork legs.
+1
without a wheel the lower stanchions are free and align perfectly with the upper, so action is very smooth. With the wheel in, they are constrained and so may not align perfectly causing stiction. Check the axle width, and for anything that might be causing misalignment, and correct so that the lower stanchions are deflected as little as possible and you should see real improvement, though it may never be as nice as whn there's no wheel.