How to identify a figure eight on a bicycle wheel

How to align a bicycle wheel

Here, an unlucky cyclist ran into a large stone, or hit a wall, the rim on the wheel bent into a “ram’s horn”, it is almost impossible to continue moving. And now what i can do?

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If the wheel rim is not cracked, then the situation is not hopeless, but quite fixable. To do this, you need to straighten this very rim, or “fix”. Ok, but how do you do it? How to remove (fix, straighten, straighten, align) the big or small eight wheels on your bike?

Types of “maintainable” bicycle curvatures

First, let’s figure out what curvature of the bicycle wheel we have to deal with. Of those curvatures that can be attributed to “fixable”, one can single out:

  • a small “figure eight”, when the curvature of the wheel rim plane is localized within the segment between two or three spokes;
  • big “eight”, when the plane of the wheel rim is curved in a segment of five to seven spokes or more;
  • “Egg” when the rim lost its round shape and became more oval.

The main ways to eliminate the curvature of the wheel rim

There are at least three ways to align (straighten, straighten) wheel rims:

  • Emergency method, with the help of physical effort of the hands and feet of the cyclist. It is used, as a rule, in case of an accident on the way, just to get to the place of more thorough repairs. In this way, great accuracy cannot be achieved. This eliminates only the strongest curvatures that interfere with the uniform rotation of the bicycle wheel in general. Smaller residual curvatures are left “for later”.
  • By manually adjusting the spoke tension. This method, with enough skill and luck, can show reasonably accurate results. But it is very time-consuming, requires patience and diligence from the bike mechanic.
  • Mechanized way, with the help of straightening racks or machines. This method gives the best results in terms of quality and accuracy. Here’s just a bad luck. not every cyclist has the right rack or machine at his disposal. If you do not have the ability, desire and patience to edit the wheel rim yourself by hand, you should give it to a specialized bicycle workshop, where such a machine will certainly be found.

Emergency method

If an emergency situation occurred on the way, which led to such a strong curvature of the bicycle wheel that it is impossible to continue moving further, and there is no one to throw the emergency bike into the trunk of a car, then the following operations should be done:

  • Place the bike upside down, on the handlebars and saddle.
  • Remove the bent wheel from the bike. You do not need to remove the camera with the tire, in this case you can drive the bicycle directly with them.
  • Determine the place of the greatest curvature. In such serious cases, it is usually obvious.
  • Using your own knee as a fulcrum, and your hands as levers, rest your knee on the top of the arch of curvature, grab at the base of this arch with your hands, and applying force with your hands, try to gradually align the rim on your knee. You do not need to be very zealous, so as not to bend it in the opposite direction.
  • Put the wheel back on the bike. Try to spin it up. If it rotates freely and does not rub against the forks (front) or frame (rear), then you can sit down and continue driving to the nearest repair site. If it still rubs, remove it back and repeat the manual knee-straightening operation.

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Editing the rim by adjusting the spoke tension

This method is valuable in that it is possible to correct both large and small curvatures (“figure eight”) of the wheel rim, while achieving very high accuracy. But in fact, this is a rather dreary business, requiring even an advanced cyclist (bicycle mechanic). patience and patience again. They say that if you have enough experience, you can do it the first time. But, you never know what they say.

In general, the method consists in combining tension and loosening of the wheel spoke nipples. With this method, numerous checks of the achieved result and alterations, a return to the original positions are inevitable.

The most important primary operation is to determine the top of the wheel rim curvature. Since the fight will be carried out with much smaller curvatures than the emergency ones, this place will not be so obvious.

All you need is a piece of chalk. We turn the bike upside down, spin the curved wheel, slowly bring a piece of chalk to its rim. When the chalk begins to “strike” on its surface, this will be the top of the “eight”.

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When correcting a small figure eight, when the curvature of the rim is on a segment within three spins, the scheme of work may look as follows: tighten the central spoke with a spoke key by 1/4 turn, loosen the two spokes on the sides by 1/8 of a turn, check the result.

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When correcting the big “eight”, when the curvature of the rim takes, for example, a segment of 7 spokes, the scheme of work can be as follows: tighten the central (4th from the beginning of the segment) spoke 1/2 turn, release two spokes on the sides ( 3rd and 5th) 1/4 turn, tighten the next two knitting needles in each direction (2nd and 6th) 1/8 turn, release the remaining needles (1st and 7th) by 1 / 8 revolutions, check the result.

The given schemes of work are only approximate, approximate, which show only the basic principle of operation: tension and loosening of adjacent spokes should be alternated, at the top of the curvature the amplitude of tension (weakening) should be greater, decreasing towards the base.

If a check of the achieved result shows that the figure eight has begun to decrease, you should continue to “twist” the spokes in the same direction and ratio, only increasing the amplitude. If the figure eight has only increased, you should return everything done to its original position, and try to change the alternation of tension and loosening of the spokes.

About mountain biking. How to fix a figure eight on a wheel and change spokes?

A figure eight on a bicycle wheel is the most common deformation. Today, when creating bicycles, the latest technologies are used, but even on an ultramodern bike, the wheel remains very conservative, spoke. The design in this case does not represent anything complicated: the bushing, but the rim and the spokes that unite them. During operation, every cyclist is faced with wheel deformation. And the appearance of the “eight” on the wheel is far from uncommon. This is due to a violation of the integrity of the rim and looseness of the spokes.

And yet why does this deformation occur? During operation, the wheel is inevitably subjected to stress as soon as the cyclist takes his place on the saddle. We add road irregularities. pits, bumps, poor coverage or lack thereof, and the question of the reasons for the emergence of “eights” disappears by itself. In addition, inexperienced cyclists often distribute their weight incorrectly on the bike, which also increases the load. Sharp braking, jumping and other extreme sports, as well as long-term operation, also make it necessary to adjust the wheels.

As you can see, during operation, the bike experiences loads that are least dependent on your riding style. Over time, the geometry of the wheel rim changes. it deforms. The speed of its manifestation depends on the presence of defects in the rim (figure eight, displacement of the “umbrella” and “egg”). It should be noted that the service life of wheels often also depends on the materials from which they are made and their quality. Sometimes inexpensive models may require repair much earlier than those made from expensive components (for example, a high-strength rim).

How can you tell if a wheel is bent? When there is a suspicion that the wheel has lost its original shape, the bike should be turned over and a thorough inspection should be started.

First you need to inspect the wheel in the place of the expected curvature. To do this, spin it, while in the case of the rear one, you can do this using the pedals. It is visually obvious that the curved sections move to the side during rotation. Now it remains to grab it with your hand in that place and stop it, which is quite difficult.

Another, more powerful way is to use a crayon or marker. When spinning the wheel, it must be brought to the rim. First of all, the stroke will remain on the bulge of the figure-of-eight. By spinning more strongly and bringing the chalk closer to the rim, you can also determine the boundaries of the curvature.

How to fix the figure eight And now the curvature is found. Each cyclist can correct it with his own efforts, and, given that deformation is not a rare phenomenon, valuable experience comes over time. There are two ways to get rid of the “disease”: power straightening; tightening and loosening the wheel spokes.

The necessary set of tools to eliminate deformation: 1) chalk to mark the area with a defect; 2) a spoke key; 3) wheel straightening machine (desirable, but not required).

The figure eight, small in size, can be eliminated without dismantling the wheel. To diagnose the problem, turn the bike upside-down to check that the wheel is in the correct position relative to the brake pads. This process can be divided into several operations. First you need to identify the deformation. As the wheel rotates, press a piece of chalk onto it. In places where the figure eight is formed, you will see a corresponding trace. This simple method will help you determine the exact location of the rim deformation.

Next is the tightening and loosening of the knitting needles, but only from a certain side, which will be described in detail below. If such manipulations are performed with inaccuracies, you can give the wheel even greater deformation. There are several ways in which it can be removed.

Power straightening Having considered this scenario possible, the wheel should be removed from the frame. However, the tire and the camera should not be removed. We turn the wheel with the bulge towards ourselves and grab the rim and tire with our hands. At the same time, the average deformation requires a hand position equal to 10 and 2 o’clock on the dial. We use the knee, putting it on the convex area, and push hard from ourselves.

If there is enough strength, this is done by weight. Or you can position the wheel vertically, with the deformed section up. In this case, the help of a partner is required, who will press the wheel to the floor. After this extreme straightening, the wheel is returned to the frame and tested.

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But this method is not always effective. It is not accurate, small deformations are not corrected. Among other things, inept actions can provoke new bends. And not every rim will give in to the impact by the foot. high-strength modern wheels will remain “with their own”. Although, if the wheel let you down somewhere along the way and the “eight” happened suddenly due to, for example, hitting a large stone, “force straightening” is the only possible way.

Adjusting the wheel spokes Correct spoke tension often affects the ride quality of your bike. The tension on the spokes adds strength and elasticity to the wheel. In this case, the tires are removed, the tension of each spoke is carefully checked. It happens that the rim is bent as a result of their general weakening. In a situation where the spokes dangle like guitar strings, they should be tightened 1 turn of the key. In the found area of ​​curvature, a spoke is searched for, located in its center, that is, at the very bulge. The turn of the knitting needle must be carried out in the direction opposite to the direction of the bulge. In this case, the spokes located on the sides of the central one are weakened.

If the figure eight is between the two nearest knitting needles, then using a special key, the first knitting needle is pulled up by a third of a turn, and the knitting needle next to it is twisted in the opposite direction, loosening the clamp also by a third. If the figure eight has a size of three spokes, the following actions are taken: tightening the central spoke by a quarter of a turn with a key; slight loosening of the outer needles (half the tension in the center).

If the figure eight has a size of seven spokes, the procedure is as follows: the central spoke is tightened by half a turn; the second and third needles must be loosened by a quarter of a turn; the fourth and fifth are tightened by one eighth; the sixth and seventh (i.e. extreme) are weakened by one eighth.

That is, the alternation of stretching and stretching the spokes should be carried out so that the extreme spokes of the figure-eight are loosened. After the procedure, the wheel is installed in its place and tested for possible distortions. If the figure eight is bent in the opposite direction, all tension is eliminated and tightening on the weakened spokes increases. After which everything is repeated, but to a lesser extent. The result of a long operation is the alignment of the wheel to a perfectly flat circle. At first, the work will not go so quickly, but with the acquisition of experience, the speed of adjusting the spokes also increases.

Changing the spokes Not all craftsmen know how to assemble wheels efficiently, and therefore it is best to learn how to do it yourself. The assembly is carried out according to a certain algorithm.

Work on a set of spokes: it is necessary to lubricate the spoke threads and the rim in places where there is contact with the nipples, otherwise the spoke will not be tensioned with sufficient rigidity; in a situation where the flanges of the hub have a countersink on the only side, the spoke heads are on the non-channeled one, it is needed to bend the spoke; nine spokes are inserted into the flange so that there is an unoccupied hole between them, and so that the heads are located on the outside. In a rear wheel situation, start from the right side of the hub; on the rim, among the holes shifted to the right, you should find the one closest to the hole for the camera nipple; the first spoke is attached to this hole, it is considered the key; from the key spoke, four holes should be counted, moving clockwise, put the next spoke and wrap the nipple; as a result, there should be three unoccupied holes between the knitting needles, the knitting needle closest to the valve hole is located to the right of it, and the cut part of the sleeve faces the master; then the remaining seven spokes are fixed, while every fourth hole of the rim is used; after turning the wheel, nine more spokes are connected to the rim, inserted into the left flange from the outside; the tenth spoke should be to the right of the key, adjacent to it, but not crossing; after mounting the tenth knitting needle, the next eight are recruited in the sequence specified above; and now the drive spokes are already in place and their heads are on the outside of the flange. In this case, the nipples are turned only for a certain number of turns; tension spokes are installed with heads on the inside of the flange. A spoke is threaded into the flange hole and the sleeve is rotated so that all the spokes in place receive a certain direction that is closest to the tangent relative to the flange. The first tensioning needle must cross the three driving ones standing in place, while each tensioning needle must pass from the outside of the first two crossed by it under the third, also crossed; the rest of the spokes get on the same principle.

Tension Before tensioning the spokes, tighten all the nipples equally. Then you need to start the process by screwing each nipple one turn. If there is a “shiver” in the needles, the tension is increased. We install the wheel for testing and remove all defects of the “eight” type.

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Eliminating the radial runout An oval egg-shaped wheel rim looks like this: one part of the rim is closer to the center than the rest. This wheel flaw appears after unsuccessful landings. It is much more difficult to fix such a breakdown than a regular figure eight: 1) remove the tire and inspect the rim; 2) turn the bike body over, spin the wheel, holding an object on top. Mark with chalk the part of the rim that will lift the item; 3) simultaneously trace three directions:. release the tension from the central spoke;. pull the adjacent knitting needles by the same number of revolutions so that there are no eight;. the spokes at the opposite end of the wheel should be tightened to prevent the appearance of an “egg” in another place.

To eliminate such an eight, considerable experience is needed, the process is characterized by its own difficulties. After correcting the “eggs”, you need to press on the knitting needles with all their weight, as in the above scheme. to shrink them. Editing the Umbrella Cyclists are familiar with the concept of an umbrella. The defect is as follows: the wheel rim is displaced to one side and is not perfectly aligned with the center of the hub. How severe this bias is for the bike itself depends on the frame design and the brake configuration. This type of malfunction often occurs when the wheel is not assembled correctly. The “umbrella” is eliminated by analogy, like the usual figure eight. On the one hand, you need to tighten the knitting needles, and on the other, loosen them. In contrast to the elimination of the usual figure eight, in the process of editing the umbrella, the effort for each next knitting needle should not be weaker, but maintain uniformity around the entire circumference.

To sum up, Eights appear on the wheels of even the most experienced and savvy cyclists. In order to straighten a wheel, you need to remember a few simple rules. Always tighten the wheel spokes carefully. there is a risk of damage to the rim. If during straightening one or more of the knitting needles are overtightened, loosen them and the adjacent knitting needles. Only then repeat the adjustment again.

When riding a bicycle, the spokes often break, being in a state of weakening. If during the pulling procedure one or more spokes of the wheel are loosened, be sure to tighten them in order to repeat the adjustment after that.

The reasons for the emergence of the eight

Eight can appear on both the front and rear wheels of the bike. The main reason for its occurrence is the operation of the wheel in off-design or extreme situations:

  • too weak and uneven tension of the wheel spokes;
  • hitting a high obstacle, strong dynamic impact on the wheel.

Additional rigidity to the wheel is given by a chamber filled with compressed air; it also acts as a shock absorber, but only within certain limits: the cyclist will not feel the impact on small stones or branches. At the same time, neither the protector nor the inflated tube will protect the wheel from the consequences of hitting a high curb or log.

Part of maintaining your bike should be checking and tightening the wheel spokes at least once a month.

Repair of an eight on a bicycle wheel

Repair of an eight on a bicycle wheel in the VeloMasterskaya company at affordable prices

The eighth wheel is called the elastic deformation of the rim, in which its surfaces do not coincide with the plane of rotation. An eight on a wheel means that if you can ride a bike, then very slowly, and without repair, such a wheel will not last long. In this state, the front wheel can touch the fork, the handbrake stops working, the spokes are unevenly tensioned or deformed. When people talk about a figure eight, they mean that the wheel rim is elastically deformed, and its shape can be restored. Repair of an eight on a bicycle wheel in our workshop can be done in the shortest possible time, even in your presence.

Wheel rim repair

It takes practice to fix an 8. It is especially difficult to fix an ovoid or elliptical rim or an umbrella shape. You can repair a figure eight on a bicycle yourself if you have a workbench, some locksmith tools, time and desire. However, most often these works are difficult to perform on their own. In most cases, the order of editing the revolver is as follows:

  • remove the damaged wheel from the bike;
  • dismantle the tire and the tube after bleeding the compressed air;
  • place the wheel rim on a reference horizontal flat surface or racks of the same level, so that the wheel hub does not abut;
  • by changing the tension of the spokes, achieve the elimination of the eight. In the most protruding places of the rim, the tension of 2-4 outer spokes should be loosened, and on the inner row, the spokes should be tightened by 1-2 turns of the nut. By gradually tightening and loosening the corresponding spokes, it is necessary to ensure that the rim lies flat on the reference surface; the spoke nuts can be pre-lubricated.

In our bike workshop, fixing the eight wheel rim will take very little time. Local dents will be removed along with the 8 fix. If the wheel rim has received severe unrecoverable plastic deformation, we can replace it with a new one.