Originally posted by Duke2.6
...the inside bearing inner race rides on takes the cornering load, so it can wear slightly in many thousands of miles, which will tend to loosen the clearance a bit....
Bearings do not wear in the conventional sense. Any increase in clearances is the result of additional seating that occurs during use. If a bearing does wear, then it is experiencing a condition that will eventually lead to failure.
The reason most manuals dictate tightening the nut down to either a certain torque or until the wheel is hard to turn is so the bearing components are properly seated and the excess grease is squeezed from the races. Only then can the assembly maintain the set clearance.
The spec in my manual says clearance should be set at .01-.02 mm. A clearance check allows play to be .01-.05 mm.