The rear axle of a bicycle is a threaded rod rigidly fixed in dropouts, which does not transmit torque, but at the same time carries the main load when the bicycle is moving. It is usually made of steel, titanium or aluminum alloy and is an integral part of the bushing.
Depending on the type of attachment, the axles can be hollow or solid. The hollow ones are used in conjunction with eccentric braces to facilitate wheel mounting and dismounting. Such axles have greater rigidity and less weight.
Another way of fastening the wheel is to fix its axle in the frame stays with special nuts. For a frame with horizontal dropouts, an axle with nuts is more suitable due to a more reliable and durable wheel attachment.
Some mountain bikes and cyclocross bikes use thru axles with a threaded end. These axles are part of the frame design and are usually supplied with it.
The thickness of the rear axle depends on the type of bike, and its length is determined by the distance between the dropouts of the frame stays. In some models of bushings, the diameter can be changed using special adapters. The following axes are usually used (the first number is the diameter, and the second is the length):
- 10×135 mm. used in most modern bicycles;
- 10x130mm. Mounts on road bikes;
- 12x150mm. bike axles for downhill and free ride;
- 10×170 mm. such axles are installed on fat bikes;
- 10x120mm. Suitable for speed track bike.
On bicycles for extreme sports of the High End level, special axles of increased thickness can be used, which have increased strength.
Bicycle hubs and rear wheel axle
When choosing a bike, many novice cyclists often look at the rear derailleur, frame, the presence or absence of a shock absorber. At the same time, insufficient attention is paid to such an important component as the wheel hub.
Broken or bent axis
Another common problem is axle curvature or violation of its integrity, caused by low-quality materials used in their manufacture, or by design features of the bushing itself. Such breakdowns are mainly characteristic of ratchet bushings, since their support bearings are too far from the axle attachment point in the dropouts of the frame feathers. The result is too large a lever, and when the load increases, the axle becomes unusable.
Padding the cone
This situation is the opposite of the previous one: the flare nuts are tightened too tightly, which causes excessive friction in the hub and the wheel loses roll. In this case, adjustment of the cones is also required, and all actions are similar to those described above.
Classification of bushings
There are two types of bushings. front and rear. The front is simpler and not subject to the same stresses as the rear, especially if a fork with a shock absorber is installed on the bike. The rear hub is used to transmit torque from the pedals to the rear wheel, the dynamic characteristics of the bike depend on it, so further we will talk about it.
Bicycle hubs vary in material and interior design. They usually consist of an axle, a hub with flanges to which the spokes are attached, and bearings. There are the following types of rear wheel hubs:
- Ratchet, in which a set of sprockets is combined with a ratchet mechanism into a single whole. Such hubs are often used on bicycles in the lower price segment.
- Cassette, in which a set of rear sprockets is installed on a special drum using a spline connection.
- Planetary with internal gear shifting, in which the gears are located inside the housing of the hub itself. They are heavy and expensive, but reliable and require little or no maintenance.
The first two types are most widespread, and planetary ones remain rather exotic, although they are often used in city bikes.
Ratchet hubs are cheaper, but less reliable and are considered outdated, so it is better to choose the cassette option.
An important factor to look for when choosing a hub is the type of bearings installed in them. Bulk ball bearings remain the most common type, but industrial bearings in cartridges are more reliable.
In the first case, tapered nuts are attached to the axis of the bicycle, which press the balls to the cups, which are structurally part of the housing of the hub itself. Units with such bearings are easy to maintain and repair, but they quickly become clogged.
In products with industrial bearings, the balls in the cassette are pressed directly into the hub. They are great for a sports bike as they offer greater efficiency and better protection from dirt. Another advantage of bushings on industrial bearings is that they do not require adjustment of the axial clearance and frequent lubrication, but they are rather difficult to disassemble.
Typically, the hub body is the wheel hub. It has flanges on which the spokes are attached, and due to the presence of a set of sprockets on the rear wheel, the spokes have a slightly shorter length on one side. In bushings with loose bearings, the inner surface has tracks along which the balls move.
How are the bushings of a bicycle lubricated? This question is relevant for many cyclists. When assembling the rear hub of a bicycle, it is recommended to use grease for bearings, such as Litol and SHRUS. For gears in the ratchet and dogs, a liquid lubricant is more suitable (you can mix it with a thick one).
It is imperative to remove old grease before application using WD 40 or kerosene. Apply a thin layer of fresh lubricant after the solvent has dried. If this is not taken into account, then excess lubricant while driving will lead to contamination, which will shorten the life of the part.
Many bicycle parts are made from chromoly hardened steels and hardened steel by manufacturers and are therefore brittle. Therefore, you need to work with them carefully, be sure to protect your eyes.
This basic safety rule will help prevent injury when disassembling the rear hub, which must be pinned into the wheel. You cannot use a vice for this.
The arrangement of the rear wheel hubs of a bicycle is such that their disassembly begins with the removal of the retaining ring. Needle-nose pliers can be used to remove the inner ring from the bearing with a locknut: the “nose” is gently pushed into the spline groove, holding the sprockets (as if directing them towards the free wheel).
Use the same method to remove the retaining ring, which has a right-hand thread (rotate it against the clock hand).
When working with the transmission, keep in mind that the direction of rotation of the pedals of the bicycle must match the direction of tightening. That is, the back sleeve is unscrewed against the clock hand. The transmission on the right will also have a right-hand thread on the rear hub.
Bicycle rear hub: device, maintenance, disassembly and assembly
One of the main parts of bicycles is the hub, the quality of which determines the main characteristic. “rolling”. There are a huge number of them, but the rear hub of the bicycle causes great difficulty, the device of which is quite complex.
It consists in the care of the bearings included in the composition. cleaning, lubricating, adjusting.
In order for these bike parts to serve for a long time, the following rules must be followed:
- sort out the rear sleeve if moisture gets on it;
- to do this the more often, the more intensively the bike is used: for a city bike, it is enough to perform actions once a season, as well as for a road bike, and for a mountain bike. twice, or even three times, more often;
- diagnose when extraneous sounds are detected or backlash appears; carry out periodic lubrication.
- Correct fit on a mountain bike
- The secret to the popularity of v brake brakes
- Adjusting hydraulic disc brakes
Removing the clamping screw
Of the tools for this work, you need a 12 wrench or a pair of allen wrenches (as in the picture). The clamping screw is rotated counterclockwise as it has a right-hand thread.
The main thing is to do it carefully so as not to split the screw. To facilitate the process, you can make a simple device that allows you to increase the length of the lever. put an additional tube on the key. Do not use brute force to avoid ruining the rear hub.
Depending on the manufacturing process, the bushings are divided into:
- cast. the most durable.
The latter are of great weight. They are placed on wheels with radially spaced spokes to increase radial loads.
To reduce weight on bicycles belonging to the high class, rear hubs with hollow axles of a larger diameter and increased rigidity are installed.
On road bridges and mountain hikes, they are installed with collapsible bearings, which are distinguished by their increased efficiency. It is not difficult to install them, and adjustment is not required.
The most common today are bicycle rear hubs equipped with tapered angular contact rolling bearings.
Disassembling the rear hub of a speed bike to adjust is not as difficult as it sounds. In order for these parts to last longer, they must be lubricated, cleaned, adjusted, and replaced in a timely manner.
How to properly disassemble the rear hub?
Prepare a comfortable, well-lit workspace for yourself. Using a puller and a whip, carefully remove the cassette from the axis. After that, we open the retaining ring and take out the bearings. Before disassembling this structure, carefully study how it works, so that later you can put everything back together without any problems.
Rear hub service
In order for your bike to work without failures, it is necessary to systematically carry out preventive diagnostics of the rear hub. It needs constant lubrication and replacement of the bearing balls. The bushing housing itself must be tightened periodically. If all these actions are not carried out in time, in the near future you will have to repair the entire wheel.
In what cases it is necessary to carry out an emergency repair of the bushing:
- A crunch of bearings is heard
If your bike displays one of these symptoms, proceed with the rear hub diagnosis immediately. Riding such a bike is simply dangerous and the bike will wear out in record time.
Putting the sleeve back
After you have disassembled the rear hub, replaced the necessary parts and lubricated it, we put everything back. This process cannot be called complicated, but it is better to show concentration and accuracy. Insert the axle and adjust it with the left cone. It must be pushed onto the axle as far as it will go. After that, it is necessary to put on washers and lock nuts. The final step is bearing alignment.
If you need to repair the rear hub, follow these instructions:
- Remove the retaining ring and axle
- We dismantle the parts that are opposite to the asterisks
- We adjust the position of the cone and locknuts (they must be loosened or tightened)
Bicycle rear hub. DIY repair
Today, a bicycle is one of the most profitable and low-cost modes of transport. However, no one canceled all sorts of breakdowns and malfunctions, so if you do not want to significantly increase the costly part of your budget, it is better to learn how to cope with small problems on your own.
One of the most important parts of your bike is the rear wheel hub. Therefore, you must be ready to carry out repair work if necessary.
How the rear hub works?
The hub is the central part of the wheel, which allows it to rotate freely. The following elements of this component can be distinguished:
Depending on the design features, the bushings are divided into:
- Without brake
- With built-in brakes
This component of the wheel is also distinguished by the material from which it is made. Usually, to create it use:
Why the bushing usually fails?
The most common causes of rear hub failure include:
- Poor bike maintenance
- Long-term wear
Any cycling enthusiast, even a beginner, should understand that systematic and timely maintenance of a bicycle is the main aspect that affects its life. Do not start the bike or ride a broken bike. Bicycle maintenance is a fairly simple and fun process that shouldn’t be a burden for you. If for a number of reasons you cannot carry out it yourself, contact a specialized service station, where, for a reasonable fee, you will be given a full diagnosis and service of the bike.
In case of impossibility of repair, you can purchase the bushing in the section “Bushings and eccentrics”.
Of those components that are most often subject to wear and tear and require systematic intervention, the carriage can be distinguished. It is on this detail that we will dwell in more detail.
The ratchet is a mechanism that is inextricably linked to the rear wheel hub. It removes the need to pedal without stopping and transfers torque from the chain to the pedals.
Experts recommend carrying out this procedure after each trip through contaminated areas.
The drivetrain plays a very important role in the operation of the entire bike, so you must carefully monitor the wear of its individual parts.
In order to install disc brakes on a bicycle, you can go to any bike workshop, or carry out this process yourself.
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.
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.
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.
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.
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.
Bicycle Rear Hub Maintenance
If you ignore the need for periodic maintenance of the rear hub of a bicycle, then the life of the “iron friend” can be greatly reduced. Experienced cyclists know what signs will indicate to disassemble / lubricate / reassemble the rear hub immediately. This process is not difficult, but you need to do everything in a certain sequence.
How to properly disassemble, clean and lubricate the rear hub
Immediately remember one truth: any service is recommended to be carried out with a snagged sleeve. Otherwise, the chances of assembling the wheel correctly and quickly are unlikely to work. this can only be done by a person who is already experienced in servicing bicycles.
THE BEST REAR COASTER BRAKE REBUILDING VIDEO!
Step-by-step instructions for maintaining the rear bicycle hub:
- Remove the cassette from the axle using a whip and a puller.
- Opening the retaining ring.
- We remove all bearings and washers. Note:the sleeve can be on industrial bearings and bulk bearings, but in any case, it is very important to remember their original location in the sleeve. This rule must be observed when removing the washers.
- We carry out a careful inspection of the bearings. if they are damaged, this means the need to replace them with new parts.
- We take out the axle. it does not understand.
- We clean the body of the rear hub of the bicycle from dirt. All internal cavities must be wiped with a dry cloth.
- When installing back, each part is thoroughly lubricated, special attention should be paid to the bearings during this process.
- The last step is to install the stopper and tighten the fastening nut. It is not necessary to apply great efforts to tighten, as this can result in a problem of free wheel rotation.
Of course, everything looks quite easy and simple, but there are a lot of nuances in servicing the rear hub of a bicycle. they must be known and taken into account in the process of work:
- Firstly, the direct disassembly of the bushing should be started only after the cassette has been removed. over, the sleeve is disassembled from the opposite side and, as a rule, it is on the left. The locknut, if any, is unscrewed with a 15 mm wrench, then the stopper is removed (again, if any).
- Secondly, you need to be extremely careful when removing washers and rings. they will need to be laid out on a pre-prepared sheet of paper in the exact order, if this moment is overlooked, the assembly of the rear bicycle hub after cleaning and lubricating it can turn into real torment.
- Thirdly, after twisting the housing of the rear hub, its axis will begin to give in. just at this moment the bearings will appear. And again, you need to be extremely careful when removing the bearings. the parts are small and easy to lose. We remove each bearing with a knitting needle or tweezers, carefully wipe it with a rag soaked in kerosene or gasoline, and put it aside. Just in the process of wiping, the bearings must be carefully inspected for damage, and if there are any, then the part must be replaced.
Note: in the articles and instructions for servicing the rear hub of a bicycle, you can find a recommendation to use acetone to wipe bearings. this is permissible, but it should be borne in mind that the aroma from such a product will not be the most pleasant, and acetone can corrode the skin on the fingers. And one more thing. many “kulibins” in order not to lose small bearings use a magnet. in no case should this be done! The fact is that the bearing is magnetized and during the operation of the bicycle, iron dust is attracted to these small parts. the fact that the hub will soon become unusable can be predicted with confidence.
It is highly undesirable to confuse the left and right parts when disassembling / assembling the rear hub of a bicycle. this can lead to wheel play. If at least one ball is lost, then you will have to carry out a full replacement of the bearings. Sometimes, when opening the bushing near the axle, you can observe iron “dust”. this means that the bearings are completely worn out, they must be completely replaced.
How To Build A Bicycle Wheel | Maintenance Monday
We work with the inner space of the bushing
After the axle has been removed, you need to carefully inspect it. As a rule, this part of a bicycle wears out very rarely, but in any case, you will need to thoroughly wipe it off from dirt and dust. This is done with a dry cloth, but in some cases (with heavy pollution), you can use gasoline. So, we wipe the left cone and examine the right one for fastening strength. Only after the axle walls are completely dry (if gasoline was used for processing), can new grease be applied to it.
Note: in no case should you use chain lubricant or some other lubricant for the rear hub of the bicycle. you will need to purchase a special tool. Bearings are often used for bearings. this lubricant will be the most suitable. Too thick a layer of grease should not be applied. during the operation of the bike, it will be squeezed out and actively absorb dirt, which leads to rapid wear of the part.
When to Service the Rear Hub
To ensure that bike parts are always in perfect technical condition, they must be regularly serviced. If we consider the rear hub of the bicycle, then for it you will need:
- periodically tighten the body;
- regularly change the bearing balls;
- at the next disassembly, lubricate all internal parts of the case;
- adjust the brake hub from time to time.
Dismantling the rear wheel itself is as easy as shelling pears, but the process of removing and disassembling / assembling the rear bicycle hub is much more difficult. And nevertheless, without such regular maintenance of the part in question, it may soon need to be overhauled or replaced.
Signs that indicate an urgent need for service on the rear bicycle hub:
- when driving, there is a strong wheel play;
- the crunch of bearings is clearly audible (this means that they are simply worn out);
- on the move, the bike body rattles and staggers;
- rolling dynamics is bad.
It is worth knowing some of the features of eliminating a particular symptom:
- If the rear hub casing is spinning, its looseness, then this can be eliminated by tightening the fastening nuts.
- If the movement of the rear wheel is difficult, then it may be necessary to loosen the retaining nut a little. most likely, too much force was applied when tightening it.
- If extraneous sounds appear when the bike is moving and the roll-forward deteriorates, you will need to replace the bearings or completely lubricate the rear hub housing.
How to carry out the installation correctly
After carrying out the above work, you need to assemble the bushing to its original position. This is done in the following sequence: right bearings. wheel axle. cone. left bearings. stopper. washers and rivets. lock nut.
It is almost always necessary to adjust the rear hub of a bicycle after assembling. This is done only on the left side. first, the lock nut is slightly loosened with a 15 mm wrench, then it is tightened to the stop, but the cone must be held in a fixed position.
Using the described method, you can completely get rid of the backlash of the axis, at least. to reduce it to a minimum. Most likely, you will have to carry out the same operation more than once, but you need to achieve synchronous movement of the axle and wheel.
Note: a slight twist is perfectly acceptable, but tightening the lock nut too tight can make it difficult to move.
This completes the maintenance of the rear bike sleeve. It will be necessary to check the quality of work. test the “iron friend” at different speeds, determine if there is a backlash, how tightly all the details are fixed, if there are any extraneous sounds. If something does not suit you, then the process of disassembling / assembling the rear hub will need to be repeated.
Maintaining the rear hub of a bike is not a daunting task. even a beginner can handle the job. But if you cannot disassemble the bushing on your own, then you need to contact a specialist. with strong pressure on the part, it can be damaged, which will require a complete replacement.
After you have lubricated the threads on the spokes, they need to be placed in the hub flange. Be sure to leave some white space in between. Then find the free hole that is located on the right side of the rim. Your reference point is the valve, it should be on the right. The first spoke is placed in it, which is fixed with a nipple. When you are done inserting the knitting needles on the right side, move to the left. Accordingly, the first spoke should be to the left of the valve. The knitting needles that we will install during the knitting process are called drive needles. And there are also tensioners that need to be inserted only after all the drive ones have been sorted out. To insert the idler knitting needles, place their ends on the inside of the hub flange. Each tension spoke must have an intersection with three drive spokes. Check the correct position of the spokes. Two drives must intersect at the top and one at the bottom. After you have secured all the idler knitting needles, tighten the nipples.
Tighten the nipples the same distance. The optimal choice is 3 turns. Now you need to tighten the knitting needles. This is very easy to do, just turn each nipple one turn. Observe the correct order and move from the valve hole.
Rear Bicycle Wheel Assembly Secrets
If you are a happy owner of a bike, then at least once in your life you had to disassemble the rear wheel of your iron friend. And there are a great many reasons for this. Worn parts require systematic replacement, and maintenance in a specialized workshop is not cheap, so it is better to learn how to carry out simple repairs with your own hands.
The rear wheel has a more complex structural principle than the front one, so the main thing is to master the skill of assembling and disassembling it. If you succeed, then there will definitely not be any problems with the front wheel.
Align wheel geometry
Before proceeding to this stage, it is necessary to say what kind of wheel damage there are. There are two problems:
- Vertical unevenness (ellipse)
- Horizontal roughness (figure eight)
If there are several irregularities, do the one that is larger in size first.
Regardless of what type of unevenness is detected on the wheel of your bike, there is a single algorithm for its elimination. You just tighten the left nipples and loosen the right ones the same number of revolutions.
Do-it-yourself disassembly and assembly of the sleeve. it is quite a difficult skill, but it can also be mastered. There are enough reasons why you will need to disassemble this component. It is necessary to lubricate the bushing, replace a worn bearing or other parts. Disassembly is indispensable here.
When all parts are lubricated and free from dirt, you can start the assembly process. We start with bearings that fit into bowls. Do not forget that the bowls also need to be greased before this. After that, we put a cone on the bearings and insert the axle of the bushing. It twists until the cone snaps into place. The final step is putting on the washer and locknut.
As you can see, everything is quite simple. The main thing is to stock up on the necessary amount of time, patience and quality cycling tools.