Keep in mind that it is not always possible to repair a wheel. If a rim or hub is damaged too much, or if the wheel
has multiple broken spokes, replacement of the complete wheel may be necessary.
Place a small drop of penetrating oil into the nipple where it meets the spoke and where the nipple enters the rim.
The oil will help reduce friction and binding between the parts. Skip this step if the spokes were treated with a
spoke preparation compound when the wheel was built.
Use a spoke wrench properly sized for the spoke nipples you are working with. We recommend the use of Park
Tool Professional Quality Spoke Wrenches.
Uniform spoke tension is the key to a strong, reliable, long-lasting wheel. Therefore, creating or maintaining
uniform spoke tension should be a primary goal during the wheel truing process. On front wheels, there should
be uniform tension among all the spokes in the wheel. On most rear wheels, because of the extra space required
by the freewheel, the spokes on the freewheel side of the wheel will necessarily be tighter than the spokes on the
non-freewheel side. How should you determine if a wheel has uniform spoke tension? Some mechanics do this
by squeezing and comparing parallel pairs of spokes. Others pluck individual spokes and gauge tension by the
tone each makes. Still others use a spoke tension meter, a tool that holds a spoke under tension between three
points and provides a reading on a scale. Refer to a book specifically covering the topic of bicycle wheels for a
discussion of the theory behind each technique.
Lateral Truing (Correcting Side to Side Errors)
Spin the wheel and look for any side to side wobble. Locate the largest wobble. If the rim wobbles to the right,
begin correcting the wobble by tightening the nipples on the left side within the area of the wobble 1/4 turn. If one
of the spokes within the wobble appears to be loose, tighten it a bit more than the others to create uniform spoke
tension. Spin the wheel in the stand, noting the impact of the adjustment.
If the rim still wobbles to the right, loosen the nipples on the right side within the area of the wobble 1/4 turn.
Again, spin the wheel in the stand, checking the impact of the adjustment. If necessary, continue tightening the
left side nipples 1/4 turn and loosening the right side nipples until the wobble is removed. Reverse the lefts and
rights in this procedure when a rim wobbles to the left.
Check the tension of the spokes. If removing a wobble requires so much loosening and tightening of nipples that
the spokes on one side are much tighter than the spokes on the opposite side, the rim itself is probably damaged,
making even spoke tension impossible. This type of wheel is going to be weak and possibly dangerous.
Replacement of the rim and spokes, or the entire wheel may be the best solution.
Radial Truing (Correcting Roundness Errors)
Spin the wheel and look for areas where the rim moves towards the calipers (high spot) or moves away from the
calipers (low spot). If the rim has a high spot, it needs to be pulled down. Locate the center of the high spot and
tighten the two closest nipples 1/4 turn. Next, radiating outward, tighten one nipple on each side of the two center
nipples 1/8 turn and, if needed, one nipple on each side of those nipples 1/8 - 1/16 turn. Check your progress
and repeat as needed.
If the rim has a low spot, it needs to be pushed up. Locate the center of the low spot and loosen the two closest
nipples 1/4 turn. Then radiating outward, loosen one nipple on each side of the two center nipples 1/8 turn and, if
needed, one nipple on each side of those nipples 1/8 - 1/16 turn. Again, check your progress and repeat as
needed. Continue removing high spots and low spots until the wheel is round.
Some of the corrections made to the spokes to make the wheel round may have affected the lateral (side to side)
truing done previously. Re-true as needed for lateral errors and radial errors until the wheel is both straight and
round.
Prestressing the Wheel
After performing each operation, the spokes should be prestressed in order to relieve any spoke windup that may
have occurred as the nipples were turned. If the wheel is not prestressed before being ridden, any spoke windup
will be relieved as the wheel is ridden. To prestress the wheel, tightly squeeze parallel pairs of spokes all the way
around the wheel. This process may cause the wheel to go slightly out of true. If so, re-true as needed.
Continue the truing and stressing process until the wheel stays true after being stressed.
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