The rim of a bicycle wheel is the metal circle that holds the tire and is connected to the center hub by the spokes. Because there is tension on the spokes, natural wear and damage to the wheel can cause the rim to be pulled out of lateral and vertical alignment. To correct this problem, you must tune the rim, more commonly known as truing the wheel.
Step 1
Remove the tire from the wheel and place the rim on a truing stand. These stands have built-in calipers to check the lateral and vertical alignment of the wheel. If you do not have a truing stand, attach an L-square to the fork of the wheel just above the rim. This is used to check the vertical alignment of the rim. The brake pads can be used to check the lateral alignment.
Step 2
Place a drop of linseed oil onto each of the spoke nipples. The nipples must turn freely as you tighten and loosen them or the spokes will be prone to breakage.
Step 3
Rotate the wheel slowly and check for the area that is the most vertically out of alignment. Count out the spokes that cover the area. If it is too flat, use a spoke wrench to loosen each of the covering spokes a quarter-turn. When looking at a wheel from the front, the spoke wrench is turned clockwise to loosen the nipple. If the area is too high, tighten the nipples a quarter turn. Tighten or loosen the nipples at the center of the vertical misalignment an additional quarter turn before moving on.
Step 4
Rotate the wheel slowly again, this time looking for the most laterally out of alignment part of the rim. To move a rim laterally, you must tighten the spokes on the opposite side of the hub flange while loosening the spokes on the same side. For example, if a wheel needs to be moved to the left, tighten the spokes that cover the affected area and lead to the left hub flange by a quarter-turn. Follow this by loosening the spokes in the same area that lead to the right hub flange.
Step 5
Alternate between correcting vertical and lateral irregularities in the wheel. Bicycle expert Sheldon Brown recommends checking each adjustment as you finish it to ensure you have made the problem better. If the alignment is worsened after your adjustment, you turned the nipples in the wrong direction and should immediately correct this issue.
Step 6
Simulate stress on the spokes when you have brought the wheel close to true. Squeeze a pair of parallel spokes until they flex slightly. Work your way clockwise around the wheel squeezing parallel spokes until every spoke has been flexed. Check the rim again to see if it is true and make any minor adjustments that are necessary.
Step 7
Check the spoke tension by plucking each spoke and comparing the sound to the sound made by the other spokes that attach to the same hub flange. If the sound is different, the spoke tension is uneven and you must loosen or tighten the spokes accordingly to balance it out.
Step 8
Wipe any excess oil on the rim after you are finished working, as this can eat away at the tube or tire if left on the rim.
Tips and Warnings
- On rear wheels, the spokes on both sides of the wheel are not the same length. The spokes that lead to freewheel or cassette side affect vertical movement more, while the spokes on the other side affect lateral movement more. Always wear safety glasses when truing a rim, as spokes can break and shoot out from the wheel.
Things You'll Need
- Truing stand
- L-square
- Linseed oil
- Spoke wrench
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