Warped bicycle wheels are very common. Bicycles seem fragile, but they undergo an incredible beating. This almost indestructible quality comes from spoke tension. The spokes pull on the rim from both sides, equalizing the pressure to provide a stiff, metal circle that supports your weight. If one of the spokes loses tension because you hit something or for any other reason, the opposing spoke pulls the wheel sideways, causing the wheel to warp. Fix it by tightening the opposing spoke to equalize the tension.
Turn the bike upside down and balance it on its handlebars and seat. Spin the warped tire with your hand. If it won't spin because it's rubbing on the brake pads, squeeze the brake caliper, release the cable and allow the pads to tip away from the wheel as if you were going to remove the wheel.
Spin the wheel. As it revolves, you will see it dip in and out where it's warped. Note where the deviance is the worst and make a mark on the wheel with a marker.
Place a spoke wrench on the spoke closest to the mark. The spoke wrench will fit on the nipple part of the spoke where it enters the rim. It's a little square or rectangular fitting that penetrates into the rim. The spoke wrench will fit around it like a small wrench or socket.
Tighten the spoke several turns. Here's where people get confused. Pretend that you are looking through the tire and rim with x-ray vision and turn the spoke wrench clockwise. If you are looking at it from the hub side of the wheel, it will be counterclockwise. If you get confused, turn the spoke until you feel it begin to get tight. If it gets loose, you're turning it the wrong direction.
Remove the spoke wrench and spin the wheel. The warp should be less than before. Place the wrench back on the spoke and turn it two or three more turns. Check the warp by spinning the wheel. Turn it a few more times and check until the warp is removed. If you have loosened the brake pads, hook them back up and use the pads as a guide. When the wheel is centered and spins evenly between the pads, the warp will be gone.
- You may hear the rim pop and squeak when tightening the spokes; that's to be expected. If the warp is extensive, you may need to tighten other spokes. Skip one, and tighten the next spoke on the same side. And remember, if you feel loose spokes, you're turning them the wrong direction.
- Mountain bike and road wheels repair the same way.