Originally Posted by cascade168
It's important to use a cutting guide, or mitre, to keep the tube end square. This is just as important as having the top and bottom head tube faces perfectly parallel. If they are not, your bearings will not get equal loading all the way around and the bearing races will wear faster on one side.
I can't see how this is possible. The top cap rests on the stem, not the steerer tube. The top cap is what adjusts tension. Unless your stem is sitting crooked somehow, its not going to affect bearing tension in any way that I can conceive.