Most band saw tires have a crown in the middle. If the blade is tracking in front or in back of the crown, you’ll find that the blade will drift left or right.
Instead of adjusting the fence to account for the drift, I find it easier to just re-track the blade so it rides right on the crown.
Be sure to pull the saw’s thrust bearings and blade guide blocks all the way back, so that the blade is free and clear of their influence when you crown the blade. Once you have the blade on the crown, carefully reset the guide blocks and bearings. With the saw blade properly in place, your band saw should work like it’s brand-new!
– Gerry Hill
Oro Valley, Arizona