Originally Posted by
FBinNY
Without seeing the bike and how you ride I can't answer. It could be hub play at the bearing, axle flex, frame flex, spoke flex, or simply that your brake is too close to one side and you could solve the problem by moving it over slightly.
IMO with seeing it, you can safely rule out the skewer because that might cause the wheel to move, but it won't cause it to flex.
Thanks for your input. There is no hub play. I just had the hub rebuilt by a trusted mechanic with new bearings. It doesn't feel like there is really any play in the hub at all.
I have checked the brake, and it is really even from side to side. I have also been riding with it all the way open (lever can almost touch the bars when I brake all the way)
I
think I have ruled out all of the obvious causes, but I'm not 100% sure, which is why I'm here.