The best way to make sure the bike wheel rim stops wobbling is to center it. The spokes all work together to keep the rim perfectly circular, each applying gentle constant traction in different directions. Since there are so many rays to consider, this repair is quite a complex art form; however, if you are patient and proceed slowly, this is a doable job for any novice mechanic.
Steps
Part 1 of 3: Adjusting the Lateral Sway
Step 1. Turn the bike upside down or put the wheel to be repaired on a wheel tracer if you have one
You need to be able to spin it freely to see the deformation and make some small adjustments. Generally, it is enough to turn the vehicle upside down, but precise mechanics use a workbench, called wheel truing, which supports the rim and at the same time is equipped with small gauges that allow you to notice the slightest irregularities.
If the wheel wobbles a lot and creates a lot of problems, it may help to remove the tread first or, at the very least, deflate the inner tube a little, otherwise you run the risk of blowing it up while you work.
Step 2. Identify the unevenness of the rim by paying attention to where it approaches the brakes
Spin the wheel by looking at the brake pad area to see which section sways from side to side. Stop the wheel at this point by using your fingers and locating the deformation or use a permanent marker to identify the crooked area. Rotate the rim while simply holding the marker at a constant height, leaving a trail where the wheel approaches the brake.
If you want to protect the wheels from ink marks, take a piece of masking tape and use it to label the deformed areas
Step 3. Know how the spokes are tightened and rotated
At first, the way you tighten them may seem counterintuitive, as you have to turn them both on the top and bottom of the wheel. You may feel that all of this contravenes the rule that screws are tightened by turning them clockwise, but there is an easy way to understand the basic concept. If you take a screwdriver and stick it into the upper part of the spoke, you have to turn the spoke to the right to tighten it and to the left (counterclockwise) to loosen it, as usual. If in doubt, think about which way you would turn the screwdriver and act accordingly.
Step 4. Grab the spokes around the problem area and squeeze them lightly to feel any play
If you don't know what a loose beam feels like, try touching others. While not all swaying wheels have loose spokes, most are affected by this problem and you can easily pinpoint the origin of the deformation. If a spoke is very loose, tighten it until it exerts the same tension as those surrounding it.
- If a spoke has a lot of play, you should repair it; however, if this occurs frequently, you should consider changing the rim, although this is a rare occurrence.
- There are cases where the spoke exerts too much tension and the wheel sways accordingly. The technique to work around this problem (shown below) is the same, you just have to remember to loosen the spoke instead of tightening it.
Step 5. Make a note of which side each spoke is pulling a certain amount of to find the cause of the sway
The spokes are in fact arranged alternately, half to the right and half to the left, and it is precisely the balance between the two sides that allows the wheel to remain centered and not swing. Consequently, if the rim wobbles to the left, it means that the spokes on the right side are too loose to maintain balance or the spokes on the left side are too tight. This is the reason why the deformity is noticeable only in certain areas; a single loose spoke alters the wheel in one place.
Follow the radius from the circle to the center to figure out which side to pull
Step 6. Tighten the one just below the problem area by turning the nipple half a turn
The golden rule in this kind of repair is proceed slowly. Use a spoke wrench, a small tool with notches that perfectly accommodate the nipple; the latter consists of a short metal sheath that covers the area of the spoke that engages in the rim; tighten it by turning it half a turn clockwise and inspect the wheel again. Remember to be patient and work calmly. You can't fix the deformation on the first turn, but avoid turning the nipple again for now.
- If you don't have a spoke wrench, you can use a pair of fine-tipped pliers; however, you should get the specific tool, which is reasonably priced, as soon as possible.
- Remember to rotate in the correct direction! If the wheel sways to the left, you need to tighten the nipple that pulls the rim to the right.
Step 7. Loosen the two spokes immediately adjacent to the one you just tightened, turning them only a quarter of a turn
In this way, you can keep the radial tension constant (along the entire circumference so that it remains perfectly round) without too much effort. Suppose you have just tightened a spoke to the right of the rim, since the wheel was swinging to the left; on the other side of this ray there are two more. Instead of continuing to tighten the spoke you are working on, thereby putting too much tension on it, just loosen the ones to the left of it. By limiting yourself to one quarter turn on each spoke, you release the same amount of tension that you applied to the right one, balancing the wheel better.
Remember this simple equation as you work: "If you tighten a spoke, you have to loosen the two adjacent ones on the other side by half in order to maintain balance." Conversely, loosening a spoke means tightening the two adjacent ones on the opposite side by half
Step 8. Spin the wheel and check for centering
After each set of adjustments, rotate the circle and check the work. You should inspect the rotation break, not just blindly tighten and loosen the spokes without evaluating progress.
Step 9. Continue following this pattern until the deformation is gone
Another trio of spokes may need to be adjusted; just remember to keep the tensile forces on both sides balanced. Never rotate each spoke more than half a turn at a time and only focus on one set of spokes at a time; by doing so, you can return to the previous conditions in case you make a mistake.
Probably, you get smaller and smaller improvements as you go through the work, turning the nipple a little at a time. At this stage you should spin the rim after each tightening, making only minor changes until the wheel is perfectly centered
Step 10. Inspect the wheel for flat areas, ie points where the rim is not balanced around the circumference
The most common problem is lateral wobble, but the tires can also wobble up and down, taking on an oval shape or flattening out where radial tension is not constant. After balancing the wheel sideways, make sure you have not accidentally deformed the circumference; in that case, you need to proceed with some pretty simple adjustments.
Part 2 of 3: Adjusting the Radial Sway
Step 1. First, check as best you can that the bike is balanced sideways
You should always be sure that there are no transverse sways before dealing with the radial ones; the latter occur when the rim is not perfectly round and you generally perceive a small bump as you pedal. This anomaly is caused by the general tension on the circumference and is easy to repair once the wheel is balanced laterally.
Step 2. Spin the wheel and look at it from the side by evaluating all the raised areas with a caliper or using your fingers
As the rim spins, place a finger, marker or set of gauges under the wheel, just below where it should touch the tread, and make note of the areas that rub the gauge. These are where the circle has become oval and you need to get rid of these bumps.
Step 3. Tighten the two spokes on either side of the deformed area by turning them half a turn each
One of them should be oriented on the right side of the circle and the other on the left. By pulling them equally you apply traction on the oval point without altering the radial centering.
Step 4. Move the calipers, marker or finger closest to the wheel and spin it again
If necessary, make other adjustments. Keep working on these two spokes until the rim no longer rubs on the gauge, tightening them a little at a time (no more than a quarter of a turn) to achieve precise centering.
After each adjustment, spin the hoop to check for any lateral sway as well, to make sure you haven't created any new deformities
Step 5. Check that some areas of the wheel are not recessed by creating flat surfaces
In this case, you need to loosen the spokes. This problem often occurs on the point diametrically opposite to that of the spokes you have just tightened, but luckily you can easily repair it. Find the two spokes corresponding to the depression and loosen them a quarter of a turn at a time, until the circle becomes a perfect circumference again.
Part 3 of 3: Troubleshooting
Step 1. Recognize a damaged circle that is simply not off-center
If the wheel does not hold balance, is clearly bent, dented or the spokes are not holding tension, you need to buy a new rim. It is often necessary to balance after a fall in which you have lost a spoke; however, repair is not always possible. If you find that you continue to work to no avail, the circle is probably unrecoverable.
Step 2. Tighten all too slow rays until you perceive them as tense as all the others; then move on to the finer adjustments
The half- and quarter-turn technique doesn't work when one spoke is considerably looser than the others. Screw it in until it feels as tense as the others around it and then proceed with the fine-tuning.
Step 3. Check that the wheel is seated well between the forks and that the brakes are well balanced if you feel like you can't center the rim
You have to understand if the wheel is really very unbalanced or if it is badly fixed to the frame. The best way to make sure is to unhook the rim as if you wanted to remove it from the forks. Tighten it back to the frame and let go of the brakes so that the wheel remains in the dead center.
Step 4. Replace any broken spokes as soon as possible, as it could harm others
When you lose one, you can continue pedaling for a while if you have no other choice to get home, but the increased pressure on the other spokes causes them to warp. If you wait too long, the wheel will crumple and other spokes could break, irreparably damaging the rim.
Advice
- You have to adjust several radii, you cannot make the circle perfectly circular by working on only one of them.
- Make sure you turn the spokes in the correct direction. Check that the nipple is at the top of the circle, if you have decided to use the "close right, loosen left" mnemonic. Imagine using a screwdriver when thinking about the direction to rotate.
- Make small adjustments at a time, turning the nipple a quarter of a turn.
- If you need to fix several rims of different bicycles, buy a professional wheel tracer, the cost of which varies between 35 and 180 euros, at bicycle shops and online.
- If you don't have a spoke wrench but you need to center the wheel, remove the wheel and remove the inner tube as well as the tape covering the head screws. Use a flat screwdriver to turn the nipples.
- Make sure you are using the correct sized spoke wrench, you can purchase it at most specialty stores. If the measurement is wrong, the nipples could become rounded and you would no longer be able to adjust the rim well.
- Sometimes, small parrot pliers are used to rotate damaged or rounded nipples.
Warnings
- When using the spoke wrench, remember to turn it in the direction opposite than normal. To tighten the spoke, rotate it to the left, to loosen it to the right instead, since you are working on the lower part of the screw.
- be careful! If you work too fast, it's pretty easy to overdo it and alter the original alignment of the circles.
