Is the inner axel sleeve really necessary?

[tintoy_imp]

Do not remove the tubes.They are there to prevent the inner race of the bearings being pushed inward too far causing the balls to ride out of their designed center position.

Also, it is very important not to over tighten the axle bolts that may cause the tube to "crush" slightly causing the same problem. It can lead to hot running bearings and ultimate failure. When torquing the axles try to go halfway between the max and min specs.

I have seen this condition due to over torquing. The wheel spins fine cold, but will drag when the bearing gets warm or hot.