Originally Posted by
rgvg
Well if I put my hand on the wheel and move it left to right I can feel it shift slightly. Sorry that's the best definition I can give you. I did try to aim for no play and no drag but I missed...
...the practical result of what you describe usually shows up in less precise feel to your steering and handling. ON a more macroscopic scale, if you leave the front wheel bearings a little bit loose on a gar (a different sort of bearing, they use roller bearings for cars, but still useful as illustration), you get very poor steering because the wheels tend to flop around incrementally instead of staying in alignment.
Before anyone jumps in here and says bikes are not cars, I suggest you try it out for yourself on your own bicycle.