Rear wheel alignments for bikes can be tricky, since it involves the tension of the spokes. In a wheel with perfect alignment, all the spokes have the exact tension. If your tire wobbles when your bike is in motion or if just a small section of your wheel hits a brake pad, you will need to have your tire fixed by a professional at a bike shop. However, if one full side of your wheel rubs on the brake pad, there is a straightforward fix you can do at home to align your rear tire.
Place your bike on a solid, even surface, such as a sidewalk. Turn your bike over, so the wheels are facing up and the seat is on the ground.
Stand behind the rear tire, and spin it with one hand. Watch the tire as it moves, using the brake pads as a guide. If the wheel is just off center, sitting closer to one pad than the other, you can make the adjustment.
Line a ruler up against the nut in the center of the wheel and note how far the nut is from your bike frame. Repeat the measurement on the other side. The distance between nut and frame should be the same on both sides. If not, your wheel needs aligning.
Deflate your tire by pressing a thin object, such as a ball point pin, inside the air nozzle on the tire. Hold it there until all the air is out of the tire.
Apply a small drop of light oil to each spoke hole. This is the space between the spoke nipple and the rim. The spoke nipple is the small, raised area between the rim and the spoke.
Turn all the spoke nipples on the off side one-quarter turn counter-clockwise with a spoke wrench. The off side is the side of the rim that is too near the brake pad.
Loosen all the spokes on the other side one-quarter turn clockwise. This will pull your wheel over to the other side.
Spin your wheel again, and check the alignment. If it is still too far to one side, repeat the process. Keep making adjustments until your wheel appears to have the same space on both sides.
Measure the distance between the axle nuts and the frame again to ensure proper alignment, and make further adjustments if necessary.