As a rule, the need to assemble a bicycle wheel arises when key parts are replaced or when buying custom-made components separately, and also if the service is in service center not included in the plans of the cyclist. Let's see how the rear wheel of a bicycle is assembled.
We will consider the rear wheel assembly technology, since it is much easier to work with the front wheels of a bicycle. The skills acquired in assembling the rear wheels of a bicycle are quite suitable for the front. For work, we need some tools: a wheel stand, a spoke wrench, a cone wrench, a set of wrenches and an ordinary straight screwdriver. To assemble the rear bicycle wheel, you need to go through several stages - this is spoke, pre-tensioning, adjusting the wheel geometry and assembling the hub.
spokes
It is necessary to lubricate the threads on the spokes and place them in the hub flange, leaving an empty hole in between. Next, we look for a hole on the right side of the rim, to the right of the valve, we will insert the very first spoke into it and fix it with a nipple. Then we begin to insert the remaining knitting needles, leaving three empty holes each. After that, you can insert the needles on the right side, leaving gaps in one hole. When with right side this work is done, you need to proceed to the left side. The procedure remains the same, but we must remember that the first spoke will be to the left of the valve. Note that the heads of these spokes must be on the outside of the hub flange. These spokes are called drive, and subsequent - tension.
Let's get to the tension spokes. Their ends should be inside bushing flange. We insert a tension spoke, it will intersect with three drive spokes, and it crosses the first two from above, and the third from below. We also fasten the remaining tension spokes, tightening the nipples one and a half or two turns.
Spoke pre-tension
First you need to twist all the nipples to the same depth. On the rear wheel, the tension of the right spokes is made large, first they need to be wrapped by 3-3.5 turns.
Next, we proceed to stretch all the spokes. To do this, wrap each nipple one turn. This must be done in order, starting from the valve hole. The next tightening should be done by tightening the nipples half a turn.
Wheel geometry correction
At this stage, we will need a stand on which we will install our rear wheel. There are two types of wheel irregularities - vertical and horizontal, respectively, ellipse and "eight". You need to start editing with the roughness that is greater.
The general principle for correcting irregularities for both cases is the same - when tightening the left nipples, the right ones are loosened by the same number of turns, and vice versa. You should not try to do this work in one pass, it is better to gradually achieve concentricity over several passes.
To adjust the "umbrella" it is necessary to evenly change the tension of the spokes on one side of the wheel, achieving the required parameters. The rear wheel of a bicycle differs in this parameter from the front wheel due to the characteristics of the hub.
Sleeve
Self-assembly of the rear hub is required, as a rule, if you yourself decide to carry out Maintenance- replacement of bearings, if these are industrial bearings, replacement of grease on bulk bearings, replacement of a star, cleaning of dirt. In principle, it is easy to assemble it.
Having in front of you all the parts of the rear hub of the bicycle, make sure that all parts are free of dust and dirt, old grease is removed from the bearings.
You need to start assembling this assembly by lubricating the cups in the hub and the cone. Then you need to insert bearings from the side without driven stars, if the bearings are loose, then they must be completely lubricated. Then we put a cone on the bearings. After that, we put the sides and from the side where the stars are, while holding the cone on the back side. Next, carefully insert the hub axle and twist it until the axle cone snaps into place, leave a slight play, then put on the washer (ring) and tighten it with a lock nut.
Now you know how to assemble the rear wheel of a bicycle. If you have assembled everything correctly, then the next maintenance will not happen soon. Do not despair if something suddenly went wrong, because professionals are not born. Over time, the necessary experience and skills will come.
Most modern bicycles are two-wheeled. The rear wheel of a bicycle, the device of which will be discussed later, is most often the leading one and begins to rotate under the action of the movement of the chain.
Device
Before disassembling the rear wheel of the bicycle, installing it on, or any other vehicle, you need to study its device.
It consists of the following components:
- sleeve;
- rim;
- knitting needles;
- tire with a tube or tire, which should have .
The device of the rear wheel hub of a bicycle is quite simple: it is attached to the rim with knitting needles (from 12 to 48 pieces).
The size of the wheel is determined by the outer diameter, which varies from 14 to 29 inches. Mountain bikes are more commonly equipped with 26-inch wheels, while hybrid or touring bikes are more often equipped with 28-inch wheels.
Rear wheel device speed bike does not include spokes. Instead, a solid disk is used, providing increased rigidity. This design is less resistant to the oncoming air flow, but has an increased windage, which complicates the ride in a side wind.
The life of a wheel depends on the design of the rim, and its strength affects the speed and safety of the ride. Modern bicycles most often complete with rims resembling a box in section. Thanks to this shape, the wheel is protected from damage when hitting a hard obstacle.
The most commonly used material for the manufacture of rims is steel or aluminum alloys. A steel rim is cheaper, but has more mass and is less resistant to corrosion. Carbon is considered the most modern material, but the price of such models is very high.
Enough vulnerable part designs. In addition to the mass of the cyclist that affects them, the spokes are regularly subjected to stress arising from the unevenness of the road surface. The spoke is fixed in the rim with a nipple. The most common materials for manufacturing are steel and aluminum.
Important! The materials of the nipple and spokes must necessarily match, otherwise the reaction between different metals will not allow you to freely tighten or change the spokes in the future.
Depending on the production process, spokes can be:
- rolled(the cheapest option);
- drawn(light, but more expensive);
- flat(the most expensive option, surpassing others in terms of mass and resistance to oncoming air flows).
Spoke is the order of fixing the sleeve, rim and spokes. It can be radial or cross. Radial provides for the installation of the sleeve without crossing the spokes with each other. With a cross, the spokes are crossed.
Sleeve
The bushing is located in the center of the wheels and is attached to the bicycle frame. Provides rotation of the wheel, eliminating slippage and turning. The rear hub contributes to the rolling of the bike - the efficiency of movement without the expenditure of energy.
The bicycle rear hub device provides the following configurations:
- the presence of free play, the absence of a braking mechanism;
- lack of free play, the presence of a brake mechanism;
- the presence of a free wheeling and braking mechanism.
Interesting to know! In the presence of a hub brake, consisting of a drum with a shoe, it becomes possible to stop the bicycle using the pedals.
The dimensions of the hub, its mass and quality affect the rolling and energy consumption of the cyclist while riding. There are three types of this node.
The 3-speed hub has a simple design, while 5- or 7-speed gears are best left unassembled. Gears of planetary systems during assembly are installed in a certain position. This work requires special equipment.
Disassembly, cleaning/lubricating
How to remove the hub of the rear wheel of a bicycle for subsequent cleaning and lubrication? The following procedure is required:
- the stopper opens;
- washers with bearings are removed;
- troubleshooting is carried out by examining the surface of the bearings: worn out elements must be replaced, the rest are cleaned with a solvent;
- the axle is removed;
- inside the case is cleaned with a soft cloth, all elements are lubricated (special attention must be paid to bearings).
How to assemble a bicycle rear wheel hub? The assembly of the rear wheel of a mountain or any other bicycle is carried out in reverse order. When installing parts inside the housing, you must first put grease on its walls.
Important! When tightening, it is necessary to avoid overtightening, otherwise jamming and excessive wear of the structure during operation are possible.
After that, the rear wheel is installed in place. How to do this is shown in the video.
Before you start disassembling the rear wheel of a bicycle to repair the hub, you must clearly understand the procedure for these steps. Otherwise, the situation will only get worse. If you are not 100% confident in your own abilities, watch the video, which will tell you everything in detail.
Service
To maintain the good condition of the mechanisms of the bicycle, it is required to service it periodically. For the rear wheel, similar work is performed as follows:
- the body is pulled up;
- defective bearings are replaced;
- mechanisms are lubricated;
- brake pads are adjustable.
Despite its unpretentiousness, the rear wheel, with prolonged use without proper maintenance, will become unusable, which will require its repair. In addition, constant adjustment of the rear wheel must be carried out to make the ride comfortable.
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 put on bicycles of the lower 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 have most widespread, and 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 it. 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 a sports bike as they have a higher coefficient useful action and better dirt protection. 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 have to apply quite a lot of force, because the ratchet was twisted all the time while you were riding a bicycle. 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.
Maintenance of the rear bushings consists of removing the old grease, cleaning the parts of 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 by the design features of the sleeve 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.
A bicycle rear wheel hub is one of the most complex and expensive bicycle mechanisms. It is the rear hub that causes the most questions among beginner cyclists. And its repair or maintenance is generally like a bad dream.
The quality of the bushings determines how much effort you spend to overcome a certain distance, in other words, the “rolling” of the bike. The rear hub is subjected to much greater loads than the front, which dictates the need to make it more massive. In addition, if the front hub has only one function (free rotation of the wheel), then the rear hub is additionally assigned functions - torque transmission, pedal-free travel, braking functions, and even sometimes internal gear shift systems (planetary hubs).
There are a lot of companies that produce hubs for bicycles and it makes no sense to list them all. It is worth noting Shimano rear hubs, in Russia these are the most common hubs, thanks to high quality and a wide price range.
Like the front hubs, the rear ones can differ in materials of manufacture, purpose, production technology, weight and strength. But the rear bushings have their own differences inherent only to them. Which ones will be discussed below.
Materials and technologies for the manufacture of rear bushings
In terms of manufacturing methods and materials, the rear bushings do not differ from the front ones. Bushings are produced by casting, turning or stamping. Cast bushings are the cheapest to manufacture, but also the least strong and the heaviest. The most optimal metal for bushings is aluminum alloy. Steel is used to produce hubs for the simplest and cheapest bicycles. The lightest and strongest hubs are made of titanium alloy, but they are so expensive that they are used only in sports professional bikes.
Rear hub types
According to the application, the rear bushings can be for road bikes, high-speed (mountain, tourist and road bikes). Road bikes usually have hubs with one driven star and a freewheel mechanism. Also, bushings for road builders are equipped with a drum brake mechanism, i.e. sleeve with foot brake. Rear bushings for sports bikes do not have a brake mechanism, but have a freewheel system. In addition, sports rear hubs are divided into cassette and ratchet.
Speed bike rear hub device
The device of the hub of the rear wheel of a high-speed bicycle provides for a set of driven stars through which torque is transmitted to the wheel. There are two types of sprocket sets - cassette and ratchet. If the sleeve is designed for a ratchet, then the drum (nut) is located outside the sleeve and is integrated into the set of stars. The ratchet itself is attached to the fork with a special thread. If the sleeve is for the cassette, then the drum is located on the sleeve itself and is attached to it using a special hollow bolt (see diagram). The cassette, in turn, is attached to the drum through a spline connection and secured with a special nut.
It is worth adding about the rotor mounts disc brake. Here, like the front hubs, there are two standards - CenterLock and 6 Bolt. The CL standard provides spline fastening and tightening with a special nut. This standard is patented by Shimano. The six-bolt mount is more popular and is used by all manufacturers of rear hubs and brake systems.
Rear hub arrangement with brake
Most single speed bikes, whether road bikes or kids bikes, have a rear hub with built-in brakes and freewheeling. These bushings perform the following functions:
- Torque transmission from the connecting rod drive star to the driven star of the rear hub and, accordingly, the wheel itself.
- Wheel free play relative to the driven star. As soon as driven star stops, the wheel continues to rotate, regardless of the pedals of the bicycle.
- The built-in brake mechanism allows you to brake by turning the pedals in the opposite direction. The essence is the same as in car drum brakes with internal pads.
The most common brake bushings of the "Torpedo" type. Such bushings were installed on most Soviet bicycles and are still used in production today. road bikes. On the oldest Soviet and some imported bicycles of the beginning of the last century, “Go” type bushings were installed. Also in Soviet times, domestic bushings with the speaking name "Motherland" were developed. The last two types are now almost never found. Therefore, we will consider in more detail the device of only the Torpedo bushings.
Based on the above diagram, let's consider how the processes inside the rear hub take place.
- Working stroke - while turning the pedals, the driving cone, rotating with its protrusions, shifts the driving rollers up, thereby wedging the bushing body, thereby rotating the wheel.
- Freeplay - as soon as the drive cone stops rotating, the body squeezes the drive rollers into the recesses between the lugs, due to this process, the connection between the drive cone and the body is lost. Loss of connection allows the wheel to rotate freely relative to the pedals.
- Braking - when the cyclist starts to push the pedal back, the driving cone begins to rotate in the opposite direction and, due to friction, rotates the brake cone with oblique protrusions. The brake rollers enter the grooves of the brake drum and the brake cone slides into the drum. The drum is moved apart by cones on both sides, pressed against the hub body and brakes the wheel.
Type "Torpedo" provides the best option braking. The stronger the force on the pedal, the stronger the braking - this ensures smooth braking.
Bearings are special parts for maintaining the performance and fixing of rotating units. Their scope applies to everything where there is rotation and mating. The bicycle did not stand aside, because, in fact, it is a full-fledged transport with all its features.
Bearings for a bicycle are installed in all its parts that rotate, change position and are under load. They can be found in the device of the drive mechanism - the carriage, wheel hubs, and more complex devices - ratchets, switches, rear shock absorbers.
Types of bicycle bearings
According to the type of construction, parts are divided into two types: rolling and sliding.
Rolling bearings are two mating parts with grooves into which rolling elements are inserted - balls. Their uniform distribution minimizes friction in the assembly and, accordingly, extends the life of the entire bearing. Fixing the position of the balls is provided by special partitions - separators. Simple parts without baffles will require more frequent adjustment.
Separated ball bearing
They are used on a bicycle in mobile units where high resistance to abrasion and pressure loads is required and slippage is not allowed - steering column, bushings, bottom bracket. They can also be installed in complex mechanisms - shock absorber hinges and switch rollers.
Plain bearings are ballless parts. They are two elements, the rotation of which occurs relative to each other tangentially. Materials for manufacturing - bronze, steel alloys, metal-layers and all that have a low coefficient of friction.
Compared to rolling bearings, they are less resistant to abrasion, since the two parts interact directly with each other. Wear provokes the appearance of a gap that causes play. Because of this, periodic replacement of the entire assembly or worn components, as well as adjustment, is more often required.
This type is used in carriage units of budget models, on switch rollers
Rolling bearings on bicycles are divided into two types: cone-cup and industrial.
The first - bulk bearings - open-type parts. Represented by a cup in which balls are distributed along the groove, fixed with a flare nut. The body is pressed directly into the part itself - steering column or carriage glass.
Industrial bearings are closed parts, fully inserted into the movable unit. This is their fundamental difference from bulk. The system is protected from moisture and dirt, resulting in a longer service life compared to cone-cup designs.
Advantages of bulk type rolling bearings:
- ease of removal and installation;
- can be adjusted in the field;
- it is permissible to change the components individually.
Disadvantages include frequent adjustment and the need to clean from trapped dust and dirt.
Industrial bearings do not require adjustment, lubrication and cleaning. The location of the balls, the amount of lubricant in the closed housing are kept constant. Water and abrasive do not get inside the cartridge.
Proms are put on bikes for aggressive riding
However, if the bearing is worn out, it will need to be replaced as a whole. Far from civilization, this is problematic. The price of “promos” is significantly higher compared to the cost of bulk ones.
Separately, it is worth noting ceramic and ceramic-metal bearings. They are fully or partially made of ceramic, which makes them more resistant to corrosion than their metal counterparts. In addition, they are better able to withstand temperature extremes. Parts of this type are installed on high-end bicycles.
Maintenance and replacement of bottom bracket bearings
Periodic cleaning, lubrication and replacement of worn parts will help to avoid sudden problems with the movement of the bike. Signs of a bad carriage condition:
- "Clamps" in the pedals - difficult rotation or cranking;
- connecting rods dangle;
- crunches.
To remove the connecting rods and bottom bracket cups, you will need special tools - pullers and an internal hex wrench. The dismantling process is as follows:
1. Turn over and fix the bike.
2. Unscrew the fixing nuts with a hollow wrench. You can also use a hammer with a chisel, however, the nuts must be knocked out carefully so as not to damage the connecting rods.
3. Using a puller, twist them off the axle. This will take a lot of effort.
4. Remove the cups from the glass with a dolly remover. The cup is first unscrewed from the side opposite to the stars. Then remove the axle.
5. Remove bearings, inspect and replace damaged parts.
6. Clean in kerosene, reinstall and lubricate. When installing, we carefully monitor the position: on the one hand, the bearing is placed with balls outward, on the other - inward.
After replacing, cleaning and lubricating, assemble the carriage in reverse order. After tightening the connecting rods, check their rotation: lack of effort and twists indicate that you need to tighten the cups, and vice versa. In these cases, you will have to repeat the disassembly and adjustment.
Prom bearings are installed immediately, adjustment is not required.
Disassembly and replacement of bearings on the front fork
The wear of the hinge assembly of the fork is manifested in backlash, heavy steering and extraneous sounds from the column. It is not recommended to put off the problem indefinitely, because the serviceability of the steering along with the brakes is a guarantee of safety.
How to change the fork bearing? At first glance, it is not easy to get close to him. The assembly is securely pressed in and hidden in the head tube. However, in practice, everything looks simple:
- Flip the bike over and unscrew front wheel.
- Put the bike in the normal position and pull out the handlebars with the take-out (you will need wrench or hexagon for inner nut).
- Unscrew the locknut with an adjustable wrench and remove the lock washer.
- Unscrew the cup.
- After dismantling the housing, carefully remove the bearing itself. The parts on the forks of most bicycles are not equipped with separators, so make sure that the balls do not crumble.
- Inspect all components carefully. Rusty, broken balls must be replaced with new ones.
- Clean the glass, bearing and cup from dirt, and then thoroughly lubricate.
From left to right: removing the handlebar, locknut and lock washer
Bearing cartridges are completely replaced with new ones. In fairness, it should be noted that partial replacement of bulk hinges is not good for the fork, and it is recommended to install another part as well. When buying a new bearing, you need to know exactly the prescribed dimensions - for different forks they may differ. If they are unknown, the part in the store is selected according to the old one.
The fork is installed in the opposite order: after the bearing is pressed in, the glass is twisted, then the washer and lock nut are thrown on. Checking the tightness of the glass: when the bike is tilted, the front wheel should deviate from the straight position by 15 to 20 degrees. If it practically does not move, it is necessary to loosen the hinge. A large deviation of the wheel indicates a weak tightening, and the glass needs to be tightened.
Wheel hub bearing replacement
The hub is not just the axis of rotation of the wheel. Without the built-in hinge mechanism, the forces on it would be transferred unevenly, and the bike would not be able to move. The same symptoms appear when the bearings are worn.
Disassembling the hub is as easy as disassembling the fork. For the rear wheel, the procedure will be slightly more complicated than for the front, as you will need to first remove the cassette with sprockets. On a single-speed bike, the retaining ring and the sprocket itself are dismantled.
In general, disassembly looks like this:
1. Remove the wheels from the dropouts.
2. Remove the sprockets using a cassette puller and a locking whip. On singlespeed, open the stopper with a screwdriver or a special spreader.
3. Using a 15 wrench, unscrew the fixing nuts. For the rear wheel hub, the nut is unscrewed from the side opposite to the stars.
4. Pull out washers and bearing units. Bulk are moved, industrial ones are replaced with new ones.
5. Clean parts and replace damaged components.
6. Pull out the axles, wipe the internal cavities of the bushings.
Assemble in reverse order. It is important to properly position the bearings and press in the cones, just as it was before disassembly. In no case should distortions be allowed, the parts should evenly fall into their rightful places. When sorting, it is not advisable to change their places. This threatens with backlash and deterioration of the wheel travel.
New bearings are pre-selected according to the old ones - they must be the same as they were before the repair. Lubrication - key moment bulkheads and replacements (in the case of the "mound"). When installing "proms", the assembly itself does not need to be lubricated, only the internal cavities of the bushing and the axle. After installation, we check the performance of the wheels: a smooth ride without play and clamps indicates that the parts are installed correctly.
Conclusion
So, a bicycle bearing, as we found out, is the most important part in every moving unit. Its good condition, timely maintenance and replacement will ensure good driving performance and safety of movement.
