Bicycle hub is one of the most important details! The "rolling" of the bicycle depends on the quality of the bushing, and this is its main characteristic. There is a huge variety of bicycle bushings, their main differences are the purpose, the materials from which they are made, their device. The strength, weight, size of the bushings depends on what they will be used on. Also, the bushings for the front and rear wheels are different from each other, due to different loads on them:

Bicycle rear hub device

It performs the function of transmitting torque from the pedals to the wheel and several other tasks. Therefore, its design, sometimes, includes freewheel mechanisms, mechanisms, internal gear shifting.

1 - eccentric, 2 - assembly of parts on the hub axis, 3, 15 - locknuts, 4, 5, 7, 13, 14 - washers, 8, 12 - sealing rings, 9, 11 - bearing cones, 10 - axle, 16 - anther, 17 - a hollow bolt for fastening the bushing drum to the body, 18 - a set of balls, 19 - a drum, 20 - a washer.

Pe device bike hub

It has a simpler structure, its main task is toensuring free backlash-free rotation wheels .

1 - eccentric, 2 - locknuts, 3 - washers, 4 - bearing cones, 5 - axle, 6 - flanges, 7 - body, 8 - set of balls.

There are different ways to make bicycle hubs, depending on the manufacturing method, the hubs can be cast, turned or stamped. Bushings are made of steel or aluminum alloys. Cast bushings are the least durable, and they weigh more than turned or stamped ones. For wheels with radial spokes, bicycle hub flanges are made stronger to withstand increased radial loads. The hub axle is made from various materials: steel, aluminum or titanium. Sometimes they produce large diameter hollow axles, this is done to reduce weight. Such bushings are usually more rigid and are used on high-end bikes. The most common bicycle hubs today are those with angular contact tapered rolling bearings. They can be adjusted as they wear and are easy to repair. There are also bushings with non-separable bearings. They are mainly installed on road and mountain bikes, have an increased coefficient useful action. They are easy to install and do not need to be adjusted.

It is also worth considering how convenient it is to change broken ones on the sleeve. If there is no disc or drum brake on the front hub, then it is very easy to change a damaged spoke for a new one; for this, the spoke must be inserted into the flange from the side. If it's a rear hub or disc brake hub, you'll have to remove the rotor and sprockets. For a more convenient change of spokes, some manufacturers have developed a bicycle hub design - with segmented flanges for straight spokes, or flangeless.

For durable and trouble-free operation of the bicycle hub, you should clean it in a timely manner, replace and adjust the bearings. To lubricate the bearings, grease should be used, and for pawls and gear rings, liquid, or a mixture of liquid and grease, should be used. Before applying a new lubricant, the old one is removed. To do this, it is better to use kerosene or WD40, after which the cleaners themselves should be thoroughly rinsed and dried. The lubricant is applied in a thin layer so that the excess does not come out during the ride, which can lead to additional contamination of the bicycle hub with dirt and dust. If you do not use the bike very often, then it is enough to carry out such work once a season. The more actively you ride a bicycle, the more often this operation should be carried out. If you notice the appearance of play or any suspicious sounds in the bearing, then it should be sorted out and adjusted as soon as possible. From time to time, the bushing body should be inspected for cracks.

Optimum driving efficiency, cadence, speed and loads on the bike are controlled by a high-speed shift mechanism. Unlike a single speed bike, a bike with multiple torque modes is able to adapt to specific riding conditions. The “high-speed” system is used on almost all types of bikes: from city and stunt bikes to racing and mountain bikes.

A common type is a planetary bushing, inside which is a gear mechanism for changing the gear ratio. The mutual arrangement and engagement of the gears is regulated by the speed switch, which, in turn, is driven by a handle on the steering wheel. The fundamental difference from the "star" transmission allowed such a gearshift system to gain a good foothold in the cycling environment.

What does a planetary hub consist of and how does it work?

The device of planetary bushings is quite complex and resembles the mechanism of an automobile gearbox. For clarity, we show the standard scheme for the entire planetary gear:

Components of the gear compartment of the high-speed hub: 1 - sun gear, 2 - satellites, 3 - carrier, 4 - epicycle

The sun gear is shown in yellow. "Sun" is rigidly fixed on the axis rear wheel bike. It is with her that the planetary gears marked in blue are engaged. To fix them, a “carrier” (green color) is used. This detail does not allow the satellites - otherwise you can call the planetary gears - to move apart and interlock with each other, and also determines their direction of movement.

The mechanism is completed by an epicyclic gear, which rotates due to pedaling. It is shown in red in the figure.

The sprocket mates with the hub mechanism via a splined drive, the hub actuator. When changing gear, it changes the speed of rotation of the carrier relative to the ring gear, due to which the bike is adjusted to the angle of the direction of the road and its speed is regulated.

Interesting feature this type of mechanism is work as a gearbox. The sun gear plays the role of a fixed element, the epicycle is the driven element of the chain, the carrier closes on the sleeve body. For example, consider how the planetary gear mechanism works on a simple three-speed planetary gear:

• Downshift. The ring gear advances the planet carrier due to its engagement with the planetary hub housing. The gear ratio is less than one and is 0.733.
• Main gear. The torque from the epicycle is transmitted to the hub due to its engagement with the planetary. In other words, the carrier is not connected to the bushing, as in first gear, but the star gear. What happens with this? The sleeve rotates faster than the carrier, and to achieve top speed more effort is required compared to a lower gear.
• The gear ratio of the increased, or third, gear is greater than one, and for three it is 1.364. The direction of movement of the carrier and the bushing are opposite, due to which its acceleration is achieved compared to the main gear.
• For planetary bushings with 5, 7 etc. speeds, the range of gear ratios is higher than that of a three-speed due to a larger number of gear mechanisms. The principle of operation of multi-speed and simple bushings will be the same. The only difference is that each planetary component will have its own fixed (like a 3-stage planetary) values ​​of gear ratios, and in general, the mechanism will have several times more of them.

Bushing manufacturers: pros and cons

Several manufacturers are engaged in the manufacture of planetary bushings for bicycles:

• Shimano,
• sram,
• Sturmey Archer,
• Rohloff.

The latter occupies a leading position in terms of the complexity of the invented mechanism. The bushing of this manufacturer includes 14 planetary components. A large number of gear ratios and high efficiency boldly compete with those of advanced star shifting systems.

Rohloff high-speed unit in section

Second place goes to SRAM - its planetarium has 12 speeds, and the gear range exceeds 400%. Shimano is a well-known manufacturer of bicycle parts and high-speed hubs. Its well-received 3, 4, 7 and 8 planetary gear hubs have been upgraded with an 11-speed derailleur system. Sturmey boasts hybrid planetary cassettes as well as other types of standard three, five and seven speed hubs.

Benefits of using planetary bushings

1. Straight chain travel and low wear on the drive and driven sprockets. From the outside, the transmission looks like a regular signalspeed.
2. Hidden from external influences, the gear shift mechanism is highly durable compared to cassettes and ratchets. All ratios of gears can be involved. Reviews from cyclists who have switched from “standard” high-speed bikes to planetary ones will boldly say this.
3. There is no need to constantly maintain the device, and it is also difficult to inadvertently damage it.

Like everything in the world, hubs with planetary gears have their “buts”:

1. Inability to use in bicycle racing due to high friction and gear sensitivity.
2. A noticeable weight gain: only some three-speed hubs weigh just under a kilogram. In motion, the weight gain on the rear wheel makes itself felt.
3. Repair of such mechanisms is almost impossible at home, and a service where planetary bushings are repaired is rarely found. The disposability of planetaries does not allow them to be brought into working condition, the best option will install a new one.
4. Outrageous cost. Of course, it is fully justified, but it makes no sense to put the gearbox from scratch on signalspeed. Much easier to buy a finished bike with it.

How to shift gears while riding a bike

It is difficult to harm the mechanism of a bicycle gearbox, but it is possible if it is systematically misused. When riding a planetary bike, there is a simple rule: shift gears without pedaling.

Strange? Not at all. The planetary mechanism is similar to a manual gearbox of a car, and there, too, when switching from one gear to another, gas is released. And “gas” for a cyclist is pedaling.

You need to switch from one gear to another a little in advance, and this is done like this:

• The bike is coasting, the efforts on the pedals are minimal.
• The gear shifts using the handle.
• After a few revolutions of the wheels (about 2 seconds) you can pedal.

Driving uphill is accompanied by a shift to a lower gear, that is gear ratio should be less than before the transition. On three-speed planetaries, it's easy: shift into first gear. With other options, it will be quite normal to switch, for example, from the third to the second.

You need to go up sequentially, that is, first the first, then the second, and so on. When resetting speeds, you can step over. In monotonous conditions where it is impossible to develop speed (a sidewalk with pedestrians, for example), it is better to use only the main gear without switching.

Bicycles with planetary bushings able to cover considerable distances without a large number of descents and ascents, so they can often be found in big cities with a developed network of roads and settlements on flat terrain. This transmission option is ideal for those who do not want to constantly fiddle with cassettes and chains, and at the same time often drive around the city, suburban villages and flat roads.

One of the main details 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, the device of which is quite complex, causes great difficulty.

( ArticleToC: enabled=yes )

They are distinguished by:

• device
• the material used for manufacturing, therefore, strength;
• weight;
• size;
• manufacturing method.

Since the bike has two wheels, there are two bushings - the front one, which allows the wheel to rotate freely, and the rear one, in addition to the function performed by the front one, the rear one is responsible for the roll of the bike, i.e. its efficient driving without an applied load.

The back design comes in several modifications:

• no free play - rear brakeless;
• without brake mechanism, but with free wheeling;
• rear hub of the bicycle with a foot brake, a freewheel device.

A feature of the latter device is that in order to stop the bike, it is necessary to rotate the pedals in the opposite direction. Inside this device, there is a brake mechanism, which consists of a drum and pads, driven by a star rotating in the opposite direction.

A variation of the drum is the worm rear hub of a bicycle, usually installed on single-speed road bikes. Despite the low efficiency, which, without a doubt, is a minus, the device has a huge resource, which crosses out the mentioned minus.

Speed ​​bikes are equipped with brakeless rear hubs, which are lighter than brake hubs, smaller in size and simpler in design. While the bike is in motion, the free play prevents the pedals from turning.

The axle of the rear hub bike can be clamped on the dropouts or on the frame. The spokes extending from it are connected to the rim, and thanks to the bearings they rotate the wheel.

A simpler device at the front wheel hub that performs only rotation bicycle wheel. The flanges located at the ends of the body, made in the form of a cylinder, have an axle, bearing assemblies, holes for installing spokes.

A more complex design at the rear bicycle hub. Its device is so difficult because, simultaneously with the rotation function performed by it, it is the basis for a ratchet or cassette.

The rear bike hub holds the wheel thanks to the axial ends of the frame stays fixed in the holes in one of the existing ways:

• using eccentrics (without dismantling the wheel and special tools);
• nuts (using a wrench to tighten them, taken at the rate of 2 pieces per bushing);

• disc bike hubs (on mountain bikes), which are designed to mount the rotor.

Material

The material used is steel, bronze, aluminum alloys.

Manufacturing methods

Depending on the manufacturing process, the bushings are divided into:

• stamped;
• turned;
• cast - the most durable.

The latter are very heavy. They are put on wheels with radially arranged spokes to increase the radial loads.

On high-end bikes, to reduce weight, they put rear hubs with hollow axles of a larger diameter and increased rigidity.

On highways and mountain bikes, they are installed with collapsible bearings, which are distinguished by increased efficiency. Installing them is not difficult, and adjustment is not required.

The most common today are bicycle rear hubs equipped with tapered angular contact rolling bearings.

Disassemble rear hub speed bike to adjust is not as difficult as it seems. In order for these parts to last longer, they must be lubricated, cleaned, adjusted, and changed bearings in a timely manner.

In the price segment, the leading positions belong to the manufacturer Shimano, whose parts are distinguished by the fact that, thanks to thrust-radial rolling bearings, the function of their adjustment and repair becomes available.

Their calling card consider the possibility of fastening spokes without flanges. best quality, according to a large number cyclists enjoy in this brand Deore LX. Alivio is considered a good option.

Noteworthy are the products of the Taiwanese company Novatec, which is confidently conquering the market.

It consists in caring for the bearings that make up the composition - cleaning, lubricating, adjusting.

In order for these bicycle parts to serve for a long time, the following rules must be followed:

• sort out the rear sleeve if moisture gets on it;
• do this the more often, the more intensively the bicycle is used: for a city bike, it is enough to perform actions once a season, as for a road bike, and for a mountain bike, twice, or even three times, more often;
• diagnose when extraneous sounds or backlash appear; carry out periodic lubrication.

What lubricates bicycle hubs? 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 a ratchet and dogs, liquid lubricant is more suitable (you can mix it with a thick one).

Be sure to remove the old grease before application, using WD 40 or kerosene. Apply fresh grease in a thin layer after the solvent has dried. If this is not taken into account, then excess lubricant when driving will lead to contamination, which will shorten the life of the part.

Disassembly and assembly

For most cassette rear hubs, the following instructions apply, allowing you to quickly and competently handle the assembly and disassembly of the rear hub of the bicycle.

The device of these parts from different manufacturers is identical. There are only minor differences that do not affect the disassembly process.

When starting repairs, it is necessary to clean the workplace so that there is no dust, threads and hairs left on it that can ruin the part.

Disassembly is discussed using the Hyperglide as an example.

Safety

Many bike parts are manufactured from chrome molybdenum hardened steels and hardened steels and are therefore brittle. Therefore, you need to work with them carefully, be sure to protect your eyes.

This basic safety rule will help to avoid injury when disassembling the rear hub, which must be knitted into the wheel. You can't use a vise for this.

The device of the bushings of the rear wheel of the 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 the locknut: the “nose” is carefully advanced into the splined groove, holding the sprockets (as if directing them in the direction of free play).

The same method is used to remove the retaining ring, which has a right-hand thread (turn it counterclockwise).

When working with the transmission, do not forget that the direction of rotation of the bicycle pedals must match the direction of tightening. That is, they unwind the rear sleeve against the clock. A right hand drivetrain will also have a right hand thread on the rear hub.

To disassemble the rear wheel hub of the bicycle, you need to pull out the cassette by removing the retaining ring. Cassettes are usually fastened with rivets. Some have asterisks of two standard sizes, therefore, having removed them, you must not disturb the order.

Sprockets should be cleaned with kerosene, methyl ethyl ketone, or acetone.

The next step is to remove the axle. To do this, you need to remove everything that is on the end of the axle opposite to the sprockets, pulling it out a distance sufficient to remove the bearings.

After removing the seal, two nests become visible on the inner ring of the bearing.

This will require special tools. Using a system of levers corresponding to the size of the sockets, the ring is unscrewed clockwise. Having coped with this work, you can proceed to the next step - removing the bearings.

Having done this, they are lubricated so that they sit well in place. From the core of the removed rear hub, you will need to remove all the washers without damaging them (there are at least three of them). They need to be wiped and kept in the same order.

Any solvent will work to clean the washers. They must dry well before assembly. Prying the bearings with a small screwdriver, they are placed on a rag.

Washers save everything.

They should be reinstalled if there are no major problems. If problems with gear shifting are noticed, you can try to remove the thinnest of them, assemble and check if the problem has disappeared.

If not, the washer is returned to its place, and the thicker one is removed. If only the thickest of washers can achieve an acceptable load, the rear hub may be worn out and needs to be replaced.

Before reassembly, make sure that the bearings are in their respective races from which they were removed. They must be installed in their places, without rearranging them to the other side of the wheel, since the gaps formed during wear are different for them.

Sufficiently small cassette bushing bearings are easily lost, but it is not recommended to use a magnet to find them, because, when magnetized, they will attract iron particles, which will lead to their rapid wear.

At the stage of their cleaning, they are wrapped in a rag to remove excess grease. The process is then repeated by soaking a clean cloth in the solvent.

If defects or obvious signs of wear are found, replace it with a new one.

Of the tools for this work, you need a key for 12 or a pair of universal wrenches(like on a picture). The clamping screw is rotated counterclockwise, since it has a right-hand thread.

The main thing is to do it carefully so that the screw does not split. 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. Brute force must not be used, so as not to spoil the rear hub.

In the picture provided in the section "How to disassemble and assemble the rear hub?" parts that cannot be removed are marked in red. If they are damaged, they will need to be replaced.

At this step, the rear hub is completely disassembled. It remains to clean the lock screw threads and other threaded connections with a wire disc brush to prevent seizing after the part is in place.

If faulty components are found, they are replaced with new ones. When assembling, the pawls are installed in the correct direction and place. Otherwise, the cassette rear hub will not rotate.

When assembling the core, a lubricant and an anti-seize agent are applied to the threads of the locking screw. In the same way that was used to remove the retaining ring, the core is fixed by applying a force of 3-7 kgf.

A lubricant is applied to the bearing channel, which works like glue, holding them in place while the rest of the parts are being installed. Now, having lubricated the ratchet ring, they are placed inside the shell.

When one side of the rear hub is assembled, the core is carefully placed in the cage, secured, the washers are installed, being very careful, the bearings are inserted into the cages so that they do not deform. On the free run, the work of the part is checked.

To screw in the combination ring, rotate the rear hub shell counterclockwise to ensure that the bearings are properly seated. If everything is assembled correctly, the ring is tightened with force.

It is easier to install them, starting from the side of the ratchet.

Installed

In order to adjust the load correctly, the cone placed in the ratchet should be fixed with a lock nut. On the transmission side, it is recommended to block the axle, center it as much as possible (if bolted).

Copiously lubricate the bearings on the side of the ratchet, screw the cones into them to set the preload, turning the locknut clockwise.

At first, the cone is not tightened too much so that it has little resistance to rotation, i.e. you can unscrew it by hand.

If the process is jammed, then, most likely, bearings that are completely worn out require replacement, and even the rear sleeve for clamping conical parts, which should not twist on its own.

The device of the cassette is such that it can be inserted in the only way: tighten the lock nut with force, checking that there is no play in the cassette. It remains to check the gap between the brake pads and the rim, as well as whether the wheel rotates freely. After the preload is set, you can fix the cone with a lock nut.

Having installed the wheel on the bike, they rotate the pedals: first in one direction - forward, then in the opposite direction to remove excess grease. It should flow out within a few minutes. The bike is ready to go.

Video: Bicycle rear hub front hub - what is it?

When choosing a bike, many novice cyclists most often look at the rear derailleur, the 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.

Types of bicycle hubs and their components

Bushing classification

There are two types of bushings - front and rear. The front is simpler and is not subjected to the same loads as the rear, especially if the bike has a fork with a shock absorber. serves to transmit torque from the pedals to the rear wheel, the dynamic characteristics of the bike depend on it, so we will talk about it further.

They differ in the material from which they are made, as well as the internal structure. They usually consist of an axle, a hub with flanges to which the spokes are attached, and bearings. There are the following types of bushings for the rear wheel:

• Ratchet, in which a set of stars is combined with a ratchet mechanism into a single whole. Such bushings are often placed on lower bikes. price segment.
• Cassette, in which a set of rear stars 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 sleeve itself. They are heavy and expensive, but reliable and virtually maintenance-free.

Rear cassette bushing Novatec d042sb-ss

The first two types are the most widespread, and the planetary ones remain rather exotic, although they are quite often used in city bikes.

Ratchet hubs are cheaper, but less reliable and considered obsolete, so it is better to choose the cassette option.

Rear bushing JOY TECH 434 for ratchet

Bearings

An important factor to consider when choosing a bushing is the type of bearings installed in them. Bulk ball bearings remain the most common type, but are more reliable in cartridges.

In the first case, flare nuts are attached to the bicycle axle, which press the balls to the cups, which are structurally part of the body of the hub itself. Units with such bearings are easy to maintain and repair, but they quickly become clogged.

Industrial bearing R8RS rear bush KT-155

In products on industrial bearings, the balls in the cassette are pressed directly into the hub. They are great for sports bike, because they have a higher 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 quite difficult to disassemble.

Hub body

As a rule, the hub housing is the wheel hub. It has flanges on which spokes are attached, and due to the presence of a set of sprockets on the rear wheel, the spokes are slightly shorter on one side. For bushings with loose bearings, the inner surface has paths along which the balls move.

Rear axle

The rear axle of the bicycle is a threaded rod rigidly fixed in dropouts, which does not transmit torque, but at the same time bears the main load when the bicycle is moving. It is usually made of steel, titanium or aluminum alloy and is an integral structural element of the hub.

Depending on the type of fastening, the axles can be hollow or solid. The hollow ones are used in conjunction with eccentric tie-downs to make it easier to install and remove the wheel. Such axles have greater rigidity and less weight.

Another way to fasten the wheel is to fix its axle in the frame feathers with special nuts. For a frame with horizontal dropouts, an axle with nuts is more suitable because of the more reliable and durable wheel mounting.

Rear hub axle Quando KT-262R 175mm on nuts

In some models mountain bike, as well as bikes for cyclocross, through axles (thru axle) are used, one of the ends of which is threaded. These axles are part of the frame design and are usually supplied with the frame.

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. Usually such axes are used (the first number is the diameter, and the second is the length):

• 10x135 mm - used in most modern bicycles;
• 10x130 mm - mounted on road bikes;
• 12x150 mm - bicycle axles for downhill and free ride;
• 10x170 mm - such axles are placed on fat bikes;
• 10x120 mm - suitable for high-speed track bike.

On bikes for extreme sports High End level, special axles of increased thickness can be used, which have increased strength.

Disassembly and maintenance of the rear hub

The rear wheel mechanism of a bicycle needs periodic maintenance and repair, and often inexperienced cyclists have trouble disassembling and reassembling it. However, this is a fairly simple operation, and after a little practice it ceases to cause difficulties. The main thing is to choose the right tool and be patient. You should also show maximum accuracy, otherwise a small part or a ball that has rolled somewhere can cause serious problems, and it will be impossible to assemble the mechanism correctly. If you are not confident in your actions, then you can even record the process on video so that during reassembly it is clear where this or that element should be installed.

Rear hub and its components

All conventional bushings are designed to be disassembled from the side opposite to the placement of the sprockets, that is, from the left. Consider the sequence of actions when disassembling a product on bulk bearings, since this design is the most common:

• First you need to unscrew the nuts and disconnect the wheel from the frame. In the case of clamps on eccentrics, no tools are even needed. After the wheel is removed, you can begin disassembly.
• Now you need to remove the sprockets, otherwise it will not be possible to get full access to the inside of the sleeve. If the wheel has a cassette, then you will need a tool called a whip and a puller. The whip is thrown over the large star and holds it, and the puller is inserted into the cassette and rotates counterclockwise. After dismantling the cassette, you need to remove the brake disc on the left side of the hub (if disc brakes are installed).
• To disassemble a ratchet wheel, you need a puller and a wrench with good leverage. You will have to apply quite a lot of force, because the ratchet has been twisting all the time while you were riding the bike. The ratchet also needs to be unscrewed counterclockwise.
• For further work, you will need two keys. A special cone key has a small thickness, it holds the bushing cone, and with the second key you need to unlock the left nut that fixes this cone. The loosened nut can be unscrewed, and now the rear axle of the bike is easily removed from the hub, giving access to the bearings and the inner surface of the wheel hub.
• Balls can be covered with metal anthers. Both must be carefully removed and put into a box. That's all, the sleeve is disassembled, now you can start maintenance and repair.

The scheme for disassembling the bushing on industrial bearings is even simpler, a certain difficulty is only the extraction of cassettes with balls, since they are quite tightly pressed into the hub. The cartridge will have to be taken out with a special tool or knocked out with hammer blows on the axis, but this must be done very carefully so as not to damage the flange.

Sometimes you have to disassemble the drum itself, on which the cassette with stars is attached. In this case, you will need a special puller with slots. But such a need arises extremely rarely, and in this case it is still better to contact the workshop.

Rear bushing maintenance consists of removing old grease, cleaning parts from dirt, checking their integrity and applying new grease. It is necessary to thoroughly rinse not only the bearings and the inner surface of the hub, but also the threads on the nuts and the axle, as sand is often stuffed into it. When twisted, it collects on the surface of the cone, which can cause crunching and even damage to the balls. For this, gasoline, thinner or special detergents are usually used. After cleaning, apply lubricant to all moving parts.

The bushing is assembled in the reverse order. If the details are not lost, then everything will pass without any difficulty.

When installing the wheel in dropouts, you should pay attention to one important point: the axle with the bushing should fit fairly tightly into them. If there is a gap, spacer washers should be inserted. Otherwise, the feathers will tighten and bend when the wheel is fixed, which can lead to permanent stresses in the feathers and, in the end, to the destruction of the structure.

Most common problems and solutions

backlash

If the bushing locknuts are not tightened enough, then during the rotation of the wheel, the rear axle will beat against the bearings. As a result, cavities appear on the paths of the cones, and the balls are deformed. If the backlash is not eliminated in time, then chips form on the cones and the inner surface of the bushing. In especially neglected cases, the balls can even jump out of the tracks and start rotating inside the hub, grinding off the axle and destroying the hub, then you have to replace the entire assembly and re-spoke the wheel.

To avoid backlash, the cones must be properly adjusted. To do this, gradually tighten the flare nut, trying to find a state in which the wheel rotates freely without beating. When the correct position is found, secure the cone with a locknut. When locking the cone, the axle often starts to rotate, and the correct position is lost, so you can clamp the right end of the axle in a vise.

Cone hauling

This situation is the reverse of the previous one: the flare nuts are overtightened, which causes excessive friction in the hub, and the wheel rolls off. In this case, adjustment of the cones is also required, and all actions are similar to those described above.

Broken or twisted axle

Another frequently occurring problem is the curvature of the axis or the violation of its integrity, caused by poor-quality materials used in their manufacture, or design features bushing itself. Such failures are mainly characteristic of ratchet bushings, since their thrust bearings are too far from the axle attachment point in the dropouts of the frame stays. As a result, there is too much leverage, and when the load increases, the axle becomes unusable.

Broken bike rear axle

Unfortunately, if the axle is broken or bent, you will have to put in a new one, as they cannot be restored. The good news is that axles are inexpensive and easy to replace. Please note that manufacturers use different threads, and cones may vary in size and fullness. Therefore, when going to the store, it is better to take them with you so as not to make a mistake when buying a replacement and choose the product that fits your hub.

Crunch or noise inside the bushing

Noises, squeaks and crunches signal that your hub needs to be serviced. And this should be done as soon as possible, otherwise everything can end very badly. First you need to disassemble the sleeve, change the lubricant and check the parts for defects. Damaged components must be replaced. If after all this the problem persists, then you should consult a specialist. It is possible that it arose due to the poor quality of the sleeve itself, and a new one will have to be installed.

The rear hub of a bicycle is a very important and often underestimated element of a bicycle, and its axle is subjected to increased loads. Sand, dirt, microscopic debris and dust have abrasive properties that destroy metal. Mechanical rear wheel failures require expensive repairs or even replacement of the entire assembly, so timely and proper hub maintenance will significantly extend the life of your bike and help you avoid unnecessary expenses.

- the central part of the wheel, resting on a fixed axle, which in turn is attached to the dropouts of the fork and the bicycle frame. A quality hub is designed to provide minimal friction when the wheel rotates, thus improving the ride of the bike. In addition, the better the hub, the longer its life and fewer problems after using the bike in wet weather and in a swamp.

Bushings have a number of distinctive characteristics, the ups and downs of which we will deal with.

Location

First of all, the bushings are divided into front and rear. The front one in its device is somewhat simpler, because it is only responsible for fastening the wheel and its rotation. The rear hub, in addition to these functions, also carries a ratchet or cassette. More details here.

What a ratchet, what a cassette is a set of sprockets necessary for shifting gears. In the first case, they represent among themselves a monolithic non-separable structure, as a rule, of 5-7 stars. In the second case, individual stars can be replaced if necessary. For example, when a more running star wears out. Cassettes usually consist of 8-11 stars. The cassette is the preferred purchase option. A bushing designed for a cassette will always be more reliable than a ratchet one and will withstand a greater weight of the rider.

Separately, we note planetary rear hubs such as Shimano SG-3C41. Their insides contain a gear shift mechanism (3-5). You can switch even standing still.

Fixation

There are 2 ways to fix the hub to the bike. A simpler and cheaper option - with two turnkey nuts for 16. More convenient and expensive - an eccentric. In this case, to remove the wheel, you only need to squeeze the eccentric handle. This process takes a matter of seconds. All high-quality bicycles will have eccentric bushings installed without fail.

brakes

In addition to mounting the wheels, the bushings are also responsible for the brakes. Thus, the hubs are divided into those that work only with V-brake brakes (for example, the Novatec 802SB 36H QR white rear hub), and which are also designed for disc brakes (Novatec D882SB-SS 36H QR10 black). It should be understood that in this case any sleeve will fit under the V-brake. There are also bushings for drum brakes, but this is a rarity in our time and is found only on rare city bikes.

Production material

Everything is simple here. Steel bushings are cheap, but heavy and subject to corrosion; aluminum - more expensive, but lighter and does not rust.

Number of spokes

The 2 most common standards are 32 and 36 spoke hubs. Of course, the fewer spokes, the lighter the wheel, but less durable, and vice versa. It is important that both the hub and the wheel rim are designed for the same number of spokes.

Size

There are different standards for hub axles. They differ in diameter - the larger it is, the more reliable the sleeve, but at the same time it will also weigh more. For an ordinary mountain and cross bike, a diameter of 9-10 mm is characteristic, a more extreme one - 14-15 mm.

The hub axles differ in length. The front ones, as a rule, are 108-110 mm, and the rear ones are longer - 135-146 mm.

An interesting option is the Novatec D882SB-SS 36H QR10 rear hub, in which the axle diameter can be changed using adapters.

Bearing type

Bushings are made on industrial bearings (they are non-separable) and bulk (they can be serviced and adjusted). The advantage of industrial bearings is that for the time being, you can ignore the unpleasant sound and other problems, and then simply replace the bearings without changing the entire bushing. An important feature of bearings is their dirt protection. So, for bulk on bushings of the lower and middle price range, protection against dirt will be better. On equally expensive bushings, there will be no difference between bulk and industrial bearings.

Having bought a good bushing once, you can forget about replacing it for 10,000 km.