According to the famous You Tube Alex Snodgrass, the wheels should not need to be shimmed ..."don't mess with the wheels".
Here's what I'd like to know.
The bottom drive wheel is not adjustable for tilt, only the top tracking wheel is. If you hold a long straight edge against the edges of the bottom wheel , where does it fall against the top wheel with the blade on? I will assume it misses by some amount say 1/8", that's OK.
Per the video, the only way to properly adjust a bandsaw is to remove the table, back out all the guides, throw a new blade on and start from there.
That way all the variables are eliminated. A blade that is welded crocked will not track right. A wheel that is not crowned right won't track right. A blade that's is too loose won't track right.
It does it with old and new blades. I've tried tracking and the bottom does follow the top out. And to get the bottom gullets near the center the top of the blade is running off the back of the wheel. Tried it with 3/4" blades and 3/8" blades, same result. Does the bottom have to be centered when the top is, or is it supposed to be near the front of the wheel when the top is centered? Can't find that answer in the owner's manual. Thanks again.
The bottom wheel is pretty much along for the ride, while the top wheel is the one that sets up everything else. Unless your saw is out of whack and someone has "messed with the wheels" there shouldn't be any thing you can't adjust out by adjusting the top wheel so the gulklets ride in the center of the tire.
Per the video the tires must be secured/glued on the wheel correctly or centrifugal force will spin the blades off.