Causes of wheel deformation
There can be several reasons due to which the wheel is pretty bent:
These problems are not so terrible and can be solved by re-spacing the wheels. It is best if the user knows the assembly of the bike and can handle it on their own, because no one knows where the problem may overtake. And, of course, in any service center, experienced specialists will provide a service for any type of repositioning.
DIY bicycle wheel re-spacing step by step instructions
The whole process of re-spacing can, in principle, be divided into three stages:
- Determining the Right Needle Length.
- Tension adjustment.
The correct calculation of the length of the spoke is calculated with a special very complex formula. But on the Internet, special programs have now appeared that will quickly calculate the length that is suitable specifically for a given bicycle. The Lexapskov calculator is very popular. Users claim that this program is very easy to use and at the same time quite accurate in calculations.
Installation is a rather long and laborious process:
Stage two: Installation
For successful wheel packing you will need:
- Knitting needles;
- Spoke key;
If this is the first time you have to re-spoke a wheel, then pay special attention to the fact that the holes on the rim are slightly offset (tilted) to the sides. The spokes from the right flange of the hub should be inserted into the holes that are offset to the right, and from the left flange to the left. Half of the spokes on each flange are leading. The other half is tail.
- Leading spokes are those that point in the direction of rotation of the rim. As a rule, they are indicated by shades of blue.
- The tail spokes are against the rotation of the wheel. Most often they are indicated by shades of red.
The first is the tail spoke, which must pass inside the flange. It should be inserted from the outside of the right flange and directed into the offset to the right of the rim bore, which is located next to the spool bore. The nipple must be closed a few turns so that the spoke cannot fall out. The next spoke should be directed into the hole in the same flange, the next spoke through three holes after the first installed.
The next step is to turn the bicycle wheel so that it is in front of the left flange of the hub. The second set of knitting needles inserted will also be the tail needles. You need to turn the rim so that the spool is at the top. We pay attention to the very first installed spoke. if it is in the first hole after the spool, then the first spoke of the left flange should be located to the left, if the first spoke in the second hole after the spool, then the first spoke of the left flange should be located on the left.
When all the tail needles are in place, you can move on to the leading needles. We turn the bicycle wheel towards us with the right flange. The leading spokes are installed from the inside of the flange. They can be inserted into any hole. After that, turn the hub clockwise so that the leading spoke intersects with the three tail spoke. It is important that it crosses the first two from the outside, and the third from the inside. You may need to bend it slightly to install. There is nothing wrong with that. The rest of the leading spokes are installed in the same way.
Radial runout (ellipse, egg)
To edit the eight, popularly called the egg is somewhat more difficult.
First of all, remove the tire to make sure the curve is the rim and not the rubber, as is often the case.
On an upside down bike, spin the wheel, and with an object on top, mark with chalk the area of the rim that lifts this object. Try to localize the very center, the main spoke.
Now you have to follow three directions at the same time: start to loosen the tension, starting with the center spoke, pull the adjacent two spokes exactly the same number of turns so that there is no figure eight, and pull the spokes at the opposite end of the wheel to prevent an egg from appearing elsewhere.
It seems very difficult (it is) and only experience is needed here. You need to understand that you will not wind up anything particularly terrible, and you can always start all over again, loosening, and then evenly pulling all the knitting needles.
Just like in the case of the figure eight. after straightening the egg, you need to seat the knitting needles, pressing on them with all your weight.
Features of radial lacing
Experienced specialists use this type of lacing mainly for the front wheels. This is explained by the fact that they are less subject to stress from the pedals and brakes. But, despite this, the wheel receives a colossal load, which is directed vertically. That is why, with radial lacing, a large number of knitting needles are used. Mechanics recommend the optimal number of spokes 32.
It is worth noting that with this method of lacing, it does not play a big role where the spoke head is facing. At the request of the cyclist, it can be directed inward of the hub flanges, and outward.
Replacing the spokes on the rear wheel of a bicycle
To remove the bend in this way, you will need to remove the wheel from the frame. In this case, you do not need to remove the tire with the camera. Turn the bulge towards you and grab the rim and tire on both sides. With medium deformations, the optimal grip of the wheel is position 10 and 2, that is, 60 degrees to both sides of the eight. We put the knee to the most convex area and press with force from ourselves.
What position of the wheel will best allow the rim to align? If there is enough strength in the leg, then you can press on the weight. An alternative is to place the wheel vertically with the defective section up. The help of a partner is needed here. He must firmly press the wheel to the floor. After straightening, the wheel is put on the frame and checked again by the rotation method.
This method cannot be called effective for several reasons:
- Can’t bend small bends.
- The rim may bend to the other side.
- Low accuracy.
- Not every rim can be subjected to simple force so easily.
This method works relatively well somewhere on the road, when the figure eight was formed suddenly due to a swoop on a large obstacle and it must be urgently straightened in order to reach the destination.
Elimination of defects in a bicycle wheel
When the area of curvature of the wheel is found, it’s time to start straightening it. Every owner of a two-wheeled vehicle can do it with their own hands, especially since such problems can arise with enviable regularity. There are two ways to eliminate the figure eight on your own:
- Power straightening, or knee, as cyclists say.
- Wheel Spoke Tightening and Loosening Method.
How to fix a figure eight wheel on a bicycle?
Of all the constituent elements of a bicycle, the most conservative is the spoke wheel. This type of wheel fits most bikes and is simple in design: a center hub, rim and spokes that connect the rim to the pivot. During the operation of the bicycle, the wheel is subject to static, dynamic and shock loads, as a result of which changes in its shape can often occur.
Determination of curvature on wheels
So, there is a suspicion of the occurrence of wheel deformation, and it remains to determine exactly where it was formed. Turn the bike upside down and fix it clearly.
The first method of identification is visual, which allows you to find the location of large and medium defects. The wheels must be spun strongly, since at low speeds the eights, even the coarsest ones, show poorly. The rear wheel can generally be pedaled. Curved sections move away from the plane of rotation to the side. At maximum deflection, the wheels must be quickly grasped in this place. It is not easy to do this at high speeds, and the hand can slip off, so it is better to resort to the following method.
Lacing a Rear 32 Spoke Wheel, 3 Cross | How to Build a Bicycle Wheel
The second method. contact, consists in marking the damaged area. As an indicator, you can take a marker, or rather a regular crayon. Spin the wheel and slowly bring the chalk to the rim. The first thing he does is strike a figure eight along the edge of the bulge. After the vertex is determined, the wheel must be spinned even more and continue to bring the chalk closer. This defines the entire area of curvature. As soon as the chalk runs over the entire rim, the test can be considered complete. The focus of the figure eight will clearly stand out with a bold line against the background of a pale stripe along the entire circumference.
Eight deformation. what is it
Bicycle wheel curvature is associated with a misconfiguration of the rim. In other words, the wheel is no longer round. A common variant is the so-called figure eight, when there is a deviation of part (or several parts) of the rim from the plane of rotation. When rotating, these areas describe trajectories in the form of eights around the central axis of rotation. When riding a bicycle, this defect is expressed in wobbling or wobbling on the go.
Riding with eights is possible, but it is unlikely to be a pleasure. In addition, deformed wheels are less resistant to stress, which will lead to further distortion and complete unsuitability of the rim. Can I fix a figure eight on a bicycle wheel myself? Yes, and it’s not difficult at all. How to do this in the article.
Wheel spoke adjustment
Attention! The spoke tension should only be changed with a spoke wrench, and never with pliers or adjustable wrenches.!
It will take patience to align a figure eight on a bicycle wheel, especially for first-timers. Tires must be completely removed.
How To Build A Bicycle Wheel | Maintenance Monday
Check the tension of all spokes first. Often times, the rim is bent due to their overall weakening. It is easy to check this: when the spokes are clearly dangling and obey the fingers like the strings on a guitar, then they need to be tightened by about 1 turn around the entire wheel. If such a problem is not observed, then nothing needs to be touched: this way you can only aggravate the eight.
We mark the defective area and proceed to the central spoke. the one located at the bulge. The turn of the spoke is carried out in the direction opposite to the direction of the bulge. The spokes on the sides of it are loosened. With a figure eight for three needles, the straightening scheme is as follows:
- Tightening the central quarter turn key.
- Weakening of the outer needles by an eighth of a turn: the weakening force is half the tension in the center.
With an eight for 7 spokes, wheel repair is done as follows:
- The center is pulled half a turn.
- Weaken two spokes (second and third) on the sides by ¼ turn of the key.
- 1/8 tightens the fourth and fifth knitting needles.
- The sixth and seventh (extreme) needles are loosened by 1/8 of a turn.
The alternation of pulling and stretching is carried out in such a way that the outer needles on the figure eight are loosened. To check the result, the wheel is hung on the bike and tested for residual curvature. If the figure eight is bent in the opposite direction, you should remove all tension and increase the tightening torque on the loose knitting needles and repeat the procedure again, but with less tightening and loosening forces.
Despite the fact that you have to tinker a lot, you can achieve the ideal result. straightening the wheel to an even circle. And if the first time the work may take too long, then with the subsequent occurrence of the eight, the repair will go much faster. Now, when a defect appears on the wheel, you can not put the bike aside, but quickly adjust the spokes yourself and resume trips.
We remove the backlash of the rear wheel
On the rear wheel, there is most often a bushing for a ratchet, much less often for a cassette. Therefore, we will consider the first option. The wheel is removed, disassembled, wiped, lubricated. Balls or bearings are installed. The axle is put in place with pre-screwed radius and locknuts.
The ratchet is removed. On the side where it is installed, the radius and locknut are tightened first. On the disc brake side. second. Do not forget to preset the tension of the bearings or balls.
When assembling, a situation often arises when the balls relax when tightening the second pair of nuts. Assistant required (third hand). If not, you can use a bicycle frame as such.
We put the ratchet in place. Checking how easily it rotates. We fix it in place with a clamping nut. We carry out the assembly in the same way as the front wheel.
The need to remove the ratchet is due to the fact that without this it is impossible to service the bushing. Otherwise, it is impossible to tighten the nuts located just under it with the required force and remove the radius nuts.
The voids when installing the wheel in place (in the pants) are also selected by installing a thick washer.
The installed wheel is pressed against the bicycle feather by a clamping nut (from the side of the ratchet) and is strongly pressed. Only after this operation does it become possible, without outside help, to set the correct tension of the balls and to properly clamp the radius and locknut both from the side of the brake disc and from the side of the ratchet.
After that, the wheel is fixed to the frame feather with two nuts, then it is checked for ease of rotation and the absence of backlash.
The rim is a round frame with a complex profile, which on one side is spoked to the wheel hub, and on the other, it provides space for securing the tube and tire. Tires are fixed on the rim either with a special groove (standard layout). this is called a box mount, or by gluing (narrow road wheels on a bicycle).
Previously, almost all manufactured rims were U-shaped, i.e. the profile was not rigid enough. Double rims are in vogue now. Two additional stiffeners make the profile as strong as possible. For extreme disciplines, there are three-, four- and even five-chamber rim profiles, but for such a strength you will have to pay with both high cost and heavy weight. And the more weight, the more difficult it is to untwist and rotate such a device. Special U-shaped rim design typical of road bikes.
Rims are usually made of aluminum and its alloys, which have replaced steel structures. Sport rims are sometimes made of carbon fiber. the maximum lightening and replacement of the spokes with solid blades is offset by the huge price and high fragility that blocks the use of such rims on difficult roads and off-road.
Bicycle wheel dimension
The rear wheel arrangement is somewhat more complicated. On some models, a drum hub is installed. and the entire transmission system through in the form of a set of gears and shafts is packed inside the hub, by analogy with automotive transmission systems. Such bushings are very convenient to use, but have a low efficiency, eating up from 8% of the load, and also have a lot of weight and a serious price.
Also, many are familiar with the brake bushings. They were installed on Soviet bicycles and are now often found in ultra-budget models. A blocking or brake mechanism is placed inside the hub, which is triggered by the reverse force of the chain.
Planetary Bike Hub
Rear Hub Axle Standards
As a rule, rear hubs are asymmetrical, as there is a cassette or rear sprocket on the right side. Because of this, the right flange of the rear hub is located closer to the middle of the hub, so the spokes on the right side are 1-2 mm shorter than the spokes on the left side.
Providing little cushioning, the spokes are primarily the basis for the stiffness, strength and lightness of a wheel. The damping moment is important to evenly distribute the load over the rim, since a completely rigid structure is very vulnerable to unevenness. The spoke itself is a long rod, bent on one side, for attaching the sleeve to the drum, and on the other ending in a thread for a nipple-nut, which secures the spoke to the rim.
There are several types of devices for their lacing:
- standard spoked wheels (stainless steel, regular zinc-plated steel or titanium are used as materials);
- disc carbon options;
- monoblock bicycle wheels, the role of spokes in which is played by carbon fiber blades.
The requirements for the quality of the spokes are very high. In a standard set, there are usually 32 or 36 spokes, on some sports models sets of 24 and 28 spokes are installed in order to facilitate the design, and on heavy. stunt, cargo and other bicycles. the number of spokes can reach 40 or even 48 pieces.
The spoke sets vary in length, and there are usually three types of spoke on the same bike: for the front wheel, for the rear wheel on the right and left. Spitsovka is a rather complicated science, and there is a separate article about it.
Also read on this topic:
Bicycle wheel. The bicycle wheel takes on the loads that arise during the operation of this vehicle. The purpose of the wheel is to support the weight of the cyclist and the entire structure of the bicycle and to cope with the shock loads that arise from
Bicycle rims. On different types of bicycles, rims with different designs are installed, but the overwhelming majority are rims of the so-called box section. They are designed for tires with bead edges. In the rim itself
Bicycle wheel size. The overall size of a bicycle wheel is the rim diameter plus the thickness of the bicycle tire. The unit of measurement for the diameter of a bicycle wheel is English inches. There are now six common bicycle wheel sizes
Double-sided bushing. Double-sided hub (Flip-Flop). a hub that is designed to quickly change the type of drive and gear ratio by shifting the bicycle wheel 180 ° along its axis. It has threads on both sides and allows you to install
Bicycle cassette. For mountain bikes, cassettes are made with a set of stars from 11-28T to 11-36T for 8-10 stars. For road racers from 11 (12).22T to 11 (12).27T for 8. 11 stars. Campagnolo mountain cassettes are road compatible with equal number of stars
- First of all, remove the wheel. A ratchet is most often included in the rear hub design. It must also be removed first, since there is a cone and a lock nut under the ratchet. Otherwise, it will not work to service the bushing.
- We disassemble the bushing and wipe all parts from old grease and dirt.
- We look at the radius nuts, raceways and the bearings themselves. If there is mechanical damage, we replace the worn part with a new one.
- After checking, we put all the parts of the bushing in place, put in a new grease. We tighten radius and lock nuts.
- We tighten the cone and locknut from the side of the ratchet, and on the other side we adjust the tension of the bearings. Often the bearings relax when the second pair of nuts is clamped. In order to avoid this, you can use the bike frame or call an assistant.
- Install the ratchet in place. Check the ease of rotation, fix.
- The wheel is assembled, and now you need to install it on the frame. If there is a gap between the locknut and the frame, then it must be filled with a thick washer.
- We press the wheel with the clamping nut from the side of the ratchet. Now it is necessary to check the correct tension of the bearings. After that we clamp the wheel on the other side.
- We check the ease of rolling and the presence of backlash. If everything is done correctly, the wheel will spin smoothly, and there will be no backlash.
Wheel set. lacing
Mostly all self-assembly wheels are assembled by the tangential method, i.e. crosses. There can be from 1 to 5 crosses depending on the number of spokes.
Wheels with 32 and 36 spokes are mainly assembled in 3 crosses, 36. possible in 4.
For some wheels I use DT Swiss washers, which are located between the hub flanges and the spoke heads. The washers center the spoke in the hole and add strength to this connection.
This is how the washers look in an already stretched wheel.
I will not tell you how to type a wheel, you can read about it here, but I will add my own note. it is advisable to screw the nipples evenly along the thread, this will allow you to immediately get a smooth wheel already at the stage of preliminary assembly.
Assembling wheels with strain gauge
The bicycle workshop offers a high-quality wheel assembly service.
This is the stage where the spokes are tensioned to their maximum value.
The knitting needles are pulled on each side alternately, i.e. passes are made on the right and left sides by 1/2 turn of the nipple alternately. When approaching the maximum tension, the rotation of the nipple decreases to 1/4 and 1/8.
At this stage, it is also necessary to monitor both radial and lateral runout and align if necessary. At the end of this stage, we get a uniform tension and such a diagram at the output.
The pre-assembly primarily involves centering the rim between the edges of the sleeve, i. E. umbrella.
Having set up the umbrella, then it is necessary to check the radial runout, i.e. egg. The norm is considered to be a radial runout of no more than 0.5 mm (at the junction it can be more) and 0.2-0.3 mm lateral runout (figure eight), although even a 0.5 mm figure eight does not bring any discomfort during operation. At this stage, the IC indicators will be connected to the wheel assembly, which show the radial and lateral runout.
How to build a Bicycle Wheel (32 Spokes, Rear wheel, 26″)
At the stage of prestretching, the egg turns out to be somewhere between 0.8-1 mm and my task. reduce to 0.5 mm or less, i.e. tighten the knitting needles in some places, loosen them in others.
After adjusting the radial runout, the stage of preliminary alignment of the spoke tension begins, since up to this point the spokes are tensioned in a discordant manner, although the wheel can be perfectly flat.
This is what the tension diagram looks like at the pre-assembly stage.
My task is to equalize the tension in such a way that the figures would be as similar to circles as possible, since if this is not done, at the output we will get a “flat” wheel with uneven tension and its diagram will be about the same, only 3 times larger.
I use the ParkTool tensometer and their program, respectively. ParkTool claims tension errors of.20% of average per side. That is, by investing in these 20%, the tension can be considered uniform. When assembling wheels, I try that the error does not exceed 8-10% per side. Having equalized the tension, go to the stage of wheel tension.
At this stage, it remains only to even out the tension even more and get its more even diagrams, keeping the beats within 0.5 mm and less for the radial, and 0.2 and less mm for the lateral. Sometimes this stage becomes the longest.
Rims, bushings, spokes
With rims and bushings, things are easier. bought and no problem, the main thing is that the number of holes would match. It is more difficult with knitting needles. they must fit in length, since neither short nor long spokes are good for assembling wheels.
The length of the spokes can be calculated with any online calculator.