Misaligned bearing "rolling surfaces" (some call these "ball tracks") are a classic cause of tight but still loose adjustment results. Anyone who has spent time in a shop (or at home w/ enough experience) trying to adjust loose ball bearings AND then also has been able to true up said rolling surfaces (as in chasing and facing head tubes or Bb shells) knows this as the improvement in bearing adjustment results after are easily seen.


Bent axles and their misaligned and now worn cones being replaced with straight axles and axially worn (or new) cones are another common example of this.


BTW the angular contact cup and cone (the usual loose ball bearing design) are quite good at making the misalignments less problematic. Why do you think the bike industry has clung to this design for so many years? It allows loose tolerances in the manufacturing of both frame/fork as well as the components being fitted to them. The increasingly common radial contact preassembled cartridge (mistakenly called "sealed bearings" by those who don't study this stuff) bearing design is actually far more sensitive to misaligned bearing installations. This is why so many hubs using "cartridge" bearings have oversized axles. What is a marketing claim of rider benefit ("stiffer axles) is really a design need with these bearings.


John, like some of us, has spent enough time in the trenches to know this. hense my +1 to his post.


This is not to say that this is the OP's problem but this is a common contributor to said problem.


headasunder also makes a good point. The need to readjust bearings after initial use is one reason why better bike shops have had a free after purchase 'tune up" offer for many decades. Those shops that don't adjust the loose ball bearings to spin freely when first assembling the bikes, hoping that the bearing will "wear in" are only creating a situation where the bearing starts it's life with too much preload and the wear right from the beginning is more rapid then need be. Unfortunately this is FAR too often the case. Since most riders don't know this or know how to check for this and the bearing won't feel "loose" the rider mistakenly believes that all is well. Andy.