In order for the bushing to last for a long time, it must be regularly serviced. Maintenance consists in cleaning the bearings and housing cups from old grease that has already collected enough dirt. Black grease indicates dirt. This grease must be changed to prevent dirt from destroying cups and bearings.
When you have completely disassembled the bushing, wipe off the old grease with a rag or paper from the bearings and bushing housing cups. Apply new grease to cups and bearings. Next, assemble the structure.
Types and design of bicycle hubs
Before you do anything with the bushing, you first need to understand its design. How to change the hub on a bicycle will become clear when you understand its design. All bushings have 4 main components:
Bicycle Hubs: Cleaning and Rebuilding
- Housing. The spokes are attached to the body and connect it to the rim. The body has cups on the sides, into which the bearings are inserted, it is hollow inside. An axis passes through the body.
- Bearings. There are two types: bulk. balls fill the cups of the body; industrial bearings. the balls are housed in a closed structure and are a one-piece bearing. Sometimes there are balls of a non-closed type that are simply fastened by a metal shape. Bearings allow the housing to rotate around an axis.
- Axis. The connecting link of the bicycle and the wheels, bearings with the body revolve around it. The axis itself remains stationary. The fastening system can be nut or eccentric. An eccentric is used on vertical dropouts to facilitate wheel removal, sometimes nuts are used on cheaper models with such dropouts. Nuts are needed on horizontal dropouts where there is no chain tensioner and single speed transmission to make it easier to center the wheel and tighten the chain. The axle for the eccentric is hollow with a hole inside, through which the eccentric is attached.
- Retaining nuts, eccentrics, locknuts and guides. The guide is screwed onto the axle thread first so that the bearings remain in their position. The locknuts fix the position of the rail on the body. The nuts are screwed onto the axle from the outside of the dropouts to secure the wheel position. Eccentrics perform the same function.
This design completely describes the front hub, but the rear hub is also part of the transmission. Rear sprockets are attached to it. Replacing the rear hub of a bicycle does not require replacing the chainrings if they are in good working order. Rear hubs differ in the type of sprocket attachment:
The sleeves also have a different number of holes for the spokes, different flange heights, different widths or O.L.D (Over-Locknut Dimension. measurement of a locknut. Length is measured with fully tightened locknuts on the hub (not on dropouts) from one locknut to another). You need to choose the right hub for your dropout width, chainline and the number of spokes on the rim.
Dismantling and replacing parts of the front hub of the bicycle
To carry out the parsing procedure, you need several wrenches. Wrenches 13, 14, 15, 16 and 17mm may be needed. The most commonly used wrenches are 14 and 15 mm. Sometimes a thin pair of wrenches are required to remove the small locknut and not damage the structure.
Remove the retaining nuts from the dropouts. Most often a 14 mm wrench is needed.
Remove the wheel from the bike. If you have a rim brake, you need to remove the pads so that the wheel can be removed.
Unscrew the locknuts. Here you need 2 keys, lock nuts can be for different key sizes and for different widths. It is necessary to hold one key on the thread of the guide, and unscrew the lock nut with the other.
Remove the guide and pull out the axle. At this point, the guides can be removed by hand.
Advice: if you cannot remove something, then do not rush to do it with great force, so as not to break the tool or sleeve. Perhaps some detail matched the other. With this problem, you can use the anti-procotic chemistry WD-40.
Pull out the bearings carefully. If you have them of a bulk type, then prepare the place of work so that they are not lost. The balls are not connected to anything in any way, so they can easily fall out and get lost. If you have industrial bearings, you will have to gently pry a thin plastic part with something to get to the balls.
Tip: Separate the balls from the right cup and the left cup, most likely they are already slightly deformed. In order not to propagate the deformation to another cup, it is best to always insert the bearings in their previous place.
Replace the bearings. Spread the balls evenly around the edges of the cup if you have a mound. Industrial just enough to slide into place.
Insert the axle, tighten the guides and locknuts. Make sure that the axle protrudes from the cups without distortions in length on one side. Slide the guides and locknuts onto it. If you have loose bearings, then a dilemma may arise: tighten tightly and eliminate the play, or leave play, but allow the bearings to rotate freely. If the backlash cannot be eliminated without strong twisting, then it is best to leave a small space, but not bring the hub to a state of complete deformation while driving.
Replace the wheel and tighten the nuts. Make sure that the wheel is level, without distortions.
How to disassemble and replace a part for a rear hub on a bicycle
The rear hubs are part of the drivetrain, so they have an additional mechanism that depends on the type of bike drivetrain:
Before you ask the question: how to change the hub on the rear wheel of a bicycle, you need to identify the cause of the breakdown. To do this, first disassemble it according to the instructions in accordance with the type in the bushings
Rear ratchet hub. The principle of operation is the same as with the front one, but after removing the wheel from the bike (after Step 2.), you need to remove the ratchet with a special puller and a wrench and continue with Step 3.
Rear hub for cassette. After dismantling the wheel (Step 2), remove the cassette with a special puller and a whip. Dismantling the drum consists in removing the locknut and the guide, after which you need to carefully remove the drum from the axis.
The fixed and single speed hubs are disassembled in the same way as the front ones, you don’t even need to remove the sprocket. If you have a BMX, then you have to remove the “driver”, it is removed according to the principle of a drum for a cassette. Sometimes there are single-speed bushings with a foot brake, for example, on a bicycle “Ukraine”, there you also need to pull out the brake mechanism.
The planetary hubs are very difficult to service due to their complex design, they usually do not require maintenance at all due to the closed mechanism. There is no single principle of maintenance of all planetary systems; each model should have its own instruction. The process is something like this: after unscrewing all the nuts, you need to remove the housing cover and remove the core. If you managed to do this, then you need to disassemble all moving mechanisms for service. It is important to remember how everything was originally, if you are doing it for the first time, so that you can collect it.
Bicycle hub replacement
The hub is an essential part of the bike design. Both bushings support the entire weight of the rider and the bike itself. All loads during landing and impacts in case of unevenness are also taken over by the hub. Therefore, breakdowns due to which the hub is replaced on a bicycle are very common.
In this article, you will learn how to change the hub on the rear and front wheel of a bicycle, we will understand the types of bicycle hubs and talk a little about their maintenance.
Do not rush to change the entire bushing at once, first identify the breakdown. Sometimes you can get by with replacing just one part: a bearing, axle, drum, or even one nut. The cost of one part will be much lower than that of the entire bushing. Disassemble the bushing, identify the breakage and replace the defective part.
If the body is deformed so much that further operation of the bushing is impossible, then you will have to change it completely. In such a situation, you will have to re-spoke the wheel, i.e. remove all the knitting needles from the hub and rim and put everything back on, if you don’t mind the knitting needles, you can simply cut them off with wire cutters.
The main elements of the rear bicycle hub
Let us consider in detail the structure of the classic non-brake bushing of the rear wheel of the bike. The support ball bearings of the mechanism under consideration are slightly enlarged in comparison with the samples located on the front axle. This is due to the increased load exerted by a person’s body weight.
The ratchet is installed in two ways, namely:
- screwing on the thread of the knot;
- can be mounted in a bushing.
Bushings with multi-stage ratchets were previously only used on high-speed models. Today this assembly is used on almost all modern bikes.
A feature of the pressed-on non-brake bushing is the right flange, which plays the role of the inner housing of the ratchet mechanism. This design can be seen in detail in the figure. In addition, on the flange there is a track of the bearing remote from the center. The body rotates perfectly on two freewheel elements, which are based on balls with a radius of one and a half millimeters.
The work of the ratchet consists in engaging the ratchet gears of the pawls, which transmit movement to the inner part of the ratchet body. As a result, the hub starts rotation, transmitted to the wheel, which interacts with the hard surface and provides the movement of the bike.
During the stopping of the torque acting on the ratchet, the pawls still rotate with the wheel. It was during this period that a number of bearings began to work, providing a smooth movement of the structure.
Sports bikes designed for maximum speed are most often fitted with screw-on ratchet hubs that can be removed along with a set of sprockets. This feature is very handy when repairing the rear hub or replacing one of the sprockets. In general, the designs of both ratchet mounting options are similar.
How To Overhaul The Hub Of A Rear Bike Wheel
How to disassemble and reassemble the rear wheel hub of a bicycle
Almost all modern bikes are equipped with non-brake freewheel bushings, which not only increase the speed characteristics of the bike, but also greatly facilitate the efforts applied by the cyclist to maintain the pace set by him.
Rear Wheel Hub Repair Basics
Rear hub breakage is one of the main causes of wheel assembly failure. Of the main reasons, one can single out both weakening and strong tightening of the cone assembly. As a result, the user can feel both a strong backlash and a difficult rotation of the wheel with a crackling bearing. But in both cases, the only correct solution would be to repair.
To do this, you need a set of 15 and 17 mm open-end wrenches. The first step is to loosen the locknut, which is the main nut backstop locking element. After that, depending on the malfunction, we loosen or vice versa tighten the flare nut. The ideal option would be a good and smooth wheel travel without visible backlash. After the end of the process, we wrap the locknut in its original position.
Often, on inexpensive bicycles, deformation of the rear hub axle can be observed. This is due to the poor quality of the parts. This malfunction is very easy to fix by replacing a better quality part. Such defects can be avoided by carrying out routine maintenance of your “pet”, which consists in cleaning and lubricating the mating elements. Bearings or seals have to be changed much less often.
With infrequent lubrication or if the axle is bent, the bearings can make grooves in the wheel hub. To eliminate this defect, the hub itself or even the entire wheel should be replaced, which is a costly measure.
Another wheel defect can be a faulty carriage. What should you do if such a nuisance happened to you? This will require dismantling the connecting rods and the sprocket system. This is a simple process for which you should gradually loosen all nuts and other assemblies, folding them in the correct order on a clean surface to exclude dust or, even worse, sand.
If this procedure still caused difficulties, simply follow these steps:
- turn off the left locknut;
- remove the carriage cup (pay special attention to the fact that a right-hand thread is cut on this side);
- take out the carriage assembly;
- we carry out a complete cleaning and flushing of the inside of the pipe;
- we wash all the elements of the carriage system, for this it is best to use kerosene or gasoline;
- now we assemble the assembly in the reverse order;
- the last step will be to check the absence of backlash and extraneous noise, which may indicate residual effects of the abrasive material.
In order to completely eliminate the appearance of undesirable, and most importantly, untimely defects, it is recommended to carry out seasonal maintenance and periodic cleaning of the rear wheel working unit. These actions will significantly extend the life of your bike and help save you money.
How to Assemble the Rear Bicycle Hub
If you want your bike to serve you for a long time and efficiently, then you must take good care of it. If you prefer to carry out the repair process yourself, then you will need knowledge and some tools. But still, repairing a bicycle is not as difficult as it might seem. The hub is responsible for the correct operation of the bicycle wheel, so you need to approach the repair of a sports bike with your own hands responsibly.
We carry out cleaning and lubrication
The bushing lubrication job begins with the bearings. When disassembling the sleeve, put them in a certain place, because they are easy to lose, and it will be difficult to assemble the part correctly. If you do lose the bearing, try to strain your memory and remember exactly where you put it. Do not use a magnet while searching. In addition to what you are looking for, the magnet will also attract various metal crumbs and small elements. If they get inside the bearing for the bicycle hub, they will actively grind it down during the working process. And this will not add days of life to the sleeve. So be careful. Removing the bearing is not difficult. Then you need to lubricate it, and then take it with a rag and make movements as if you are trying to rub this lubricant into it. So its excess is effectively removed. Then soak a rag in solvent and wipe the bearing on all sides. You will be able to see how much the bearing is worn down, whether there is serious damage on it. If there are any, for example, the balls are damaged, then it is better to replace the bearing. Never assume that different bearing parts are interchangeable. Do not rearrange the cage, left cone or balls from another bearing into one of them. it will not work more efficiently. In addition, place the bearing exactly where you removed it from; do not replace it from one side of the wheel to the opposite. The thing is that during operation, whatever one may say, but grinds off. And this process has its own characteristics and creates different sizes of bearing clearances. It is these nuances that will help to assemble the part correctly.
After cleaning the bearings, it is necessary to clean the bushing itself. This is not difficult. just wipe the hub with a cloth dampened with brake cleaner. This will help remove old grease before applying new grease. Also, don’t forget about the carving. You should brush it gently enough using a wire brush. Having completed all these steps, you can proceed to assembling the rear bicycle hub.
Where to begin?
Bushing repair begins with its disassembly. This is a rather laborious process, during which one should not forget about safety precautions. The most common hubs that are installed on modern bicycles are cassette hubs. The bushing, as well as all its parts, are made of steel, which is only superficially sealed. Therefore, such bushings are quite wear-resistant, but under the influence of a large load or pressure, they turn out to be quite fragile. Therefore, while working, do not forget to protect your face, and most importantly. eyes. For the same reason, do not clamp the bushing and any of its elements in a vice. during the working process, they may not withstand.
How to assemble the sleeve?
Collecting everything correctly, without forgetting about anything, is quite difficult for the first time. But after you have managed to disassemble the wheel, you already have a basic understanding of this process. Now you need to put all the details in their place. We start by installing the retaining ring and remember that this is a rather fragile element, so the work must be done carefully, and do not forget that the dogs must also be installed in their places. Otherwise, the wheel will not spin. Next, we install the core of the bicycle hub. Before doing this, the thread of the locking screw must be well lubricated. We fix the core, fixing it clockwise.
Bike Wheel Problems? Try Replacing your Hub!
In order to know how to assemble the rear hub of a bicycle, you need to remember well the sequence of actions and places of parts during disassembly. This also applies to bearings. After the core is installed, apply sufficient grease to the bearing location to keep the bearing in place. All. you have assembled one side of the rear hub. We place it in its holder and secure it. We install the pre-tension washers, lubricate them well enough, and now we insert the bearings into the cages where they were previously. The main thing is to make sure that the balls are where they should be and that they did not end up in other parts of the bushing. This can lead to complete breakage of the bushing. Next, we install the combined ring. In order to check the correctness of how the bearings are installed, we turn the outside of the sleeve counterclockwise. Now you can give a little load and check the operation of the rear hub in free motion.
The final step in the process to assemble the bike hub is to set the load. To do this, gradually screw the bearings into the cones to establish the initial load. Secure the bearing clockwise using a locknut that is not secured to the left cone. Now tighten the left cone lightly, but so that its resistance is minimal and you can easily remove it. Thanks to this, you can check the level of operation of the bearings. if during manipulations the left cone does not want to twist or is jammed, then you will have to completely replace the bearings. Now you can insert the cassette and tighten the lock nut. Inspect the wheel on each side, spin it a little. this action should be easy. Wipe off excess grease from the rear hub. Remember that regular maintenance of the bike hubs is required.