What you need to know to remove the combination ring from 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. The removed rear sleeve will need to be removed from the core, and without damaging all the washers (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.
They should be reinstalled if there are no major problems. If you notice problems with shifting gears, you can try to remove the thinnest of them, collect and check if the problem has disappeared.
If not, replace the washer and remove the thicker one. If only the thickest of the washers achieves acceptable load, the rear bushing may be worn and need to be replaced.
Sufficiently small bearings of cassette bushings are easily lost, but it is not recommended to use a magnet to search for them, because, being magnetized, they will attract iron particles, which will lead to their rapid wear.
At the stage of cleaning them, they are wrapped in a rag to remove excess grease. Then the process is repeated by soaking a clean cloth in the solvent.
If defects or obvious signs of wear are found, replace with a new one.
In the picture provided in the “How to disassemble and assemble the rear hub?” parts that cannot be removed are marked in red. If you damage them, you will have to change.
In this step, the rear hub is completely disassembled. It remains to clean with a wire disc brush the threads of the locking screw and other screw connections to prevent galling after the part is in place.
Next, check for cracks and chips all the components, including the pawls, which, in order to remove, you must pull back and raise the retaining snap ring.
We collect the core, lubricate and anti-seize agent are applied to the thread of the locking screw. In the same way that I used to remove the retaining ring, fix the core, applying a force of 3-7 kgf.
Grease is applied to the bearing bore, which works like glue, holding them in place while the rest of the parts are installed. Now, having lubricated the ratchet ring, they are placed inside the shell.
When one side of the rear bushing is assembled, the core is carefully placed into the cage, secured, washers are installed, exercise maximum care, insert the bearings into the cages so that they do NOT deform. When free running, check the work of the part.
To screw in the combination ring, rotate the rear sleeve shell counterclockwise to make sure the bearings are installed correctly. If everything is assembled correctly, the ring is tightened with force.
Installation of bearings
Easier to install from the ratchet side.
What bushings does the industry produce?
They differ in:
- The material used for manufacturing, therefore, strength;
- Manufacturing method.
Since a bicycle has two wheels, there are two bushings. the front one, which allows the wheel to rotate freely, and the rear, in addition to the function performed by the front, the rear is responsible for rolling the bike, i.e. Its efficient ride without any applied load.
The rear design comes in several modifications:
- There is no free wheeling. rear brakeless;
- Without a brake, but with a free wheel;
- Bicycle rear hub with foot brake, freewheel device.
The peculiarity of the device of the latter 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, a drum and pads, driven by a star rotating in the opposite direction.
A type of drum is a worm-gear rear bicycle hub, 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 negates the mentioned minus.
Speed bikes are equipped with non-braking rear hubs, which are lighter than brakes, smaller and have a simpler design. Free play prevents the pedals from rotating while the bike is in motion.
It consists in the maintenance of the bearing, which is part of. cleaning, lubricating, adjusting.
In order for these bike parts to serve for a long time, the following rules must be followed:
- Go through 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 highway, and for a mountain bike. twice, or even three times, more often;
- Diagnose when extraneous sounds or backlash is detected; conducts periodic lubrication.
- Correct fit on a mountain bike
- The secret to the popularity of v brake brakes
- Adjusting hydraulic disc brakes
How are bike bushings 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 a ratchet and dogs, a liquid lubricant is more suitable (you can mix it with a thick one).
It is imperative to remove the 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.
Depending on the manufacturing process, the sleeves are divided into:
- Cast. Most durable.
The latter are of great weight. They are placed on wheels with radially spaced spokes to increase radial loads.
In order to reduce weight on bicycles belonging to the high class, rear hubs with hollow axles of a larger diameter and increased rigidity are installed.
The most common today are bicycle rear bushings equipped with tapered angular contact rolling bearings.
Disassemble the rear hub of a speed bike to adjust, not as hard as it sounds. In order for these parts to last longer, they must be promptly lubricated, cleaned, adjusted, and replaced with bearings.
Bicycle rear hub: device, maintenance, disassembly and assembly
One of the main parts of bicycles is the hub, the quality of which depends on 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.
Many bike parts are manufactured from chromoly hardened steels and hardened steels and are therefore brittle. Therefore, you need to work with them carefully, be sure to protect your eyes.
The arrangement of the rear wheel hubs of the bicycle is such that disassembly x 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 gently advanced into the spline groove, holding the sprockets (as if directing them towards the free wheel).
Use the same method to remove the locking ring, which has a right-hand thread (rotate it against the clock hand).
When working with the transmission, do not forget 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 located on the right side of the rear hub will also have a right-hand thread.
What is the difference between a ratchet and a cassette
Ratchet is a ratchet mechanism with a threaded or slotted mount on the hub. The ratchet is outside and the sprockets are completely installed. This means that the ratchet is put “on time”. when, say, small sprockets are worn out, it will not work to replace only the worn part of the day. everything changes at once.
This type of knot was widespread in the last century, and now it can be found on a budget high-speed bike. Some of the disadvantages of the ratchet include:
- A small number of stars. from 5 to 7 speeds;
- Low running resource;
- For more durable products, the cost will be many times higher.
Although, of course, repair, or rather, non-maintainability, is the main disadvantage. Most ratchets are threaded. An unpleasant feature of this mount is jamming. It looks like this: after a certain run, it will twist onto the sleeve so that it will be problematic to disassemble it later.
Ratchets and cassettes differ in both fastening and puller
Now in cassettes. In fact, this is the same ratchet, only the ratchet is hidden inside the drum. It is installed only on splines, which is why it is sometimes problematic to switch from the ratchet (if that rare spline copy was not standing). In comparison with its “brothers”, the cassette drum mechanism has a number of advantages:
- More sprockets are 9 to 11 on modern models;
- The system weighs less, which means the bike as a whole, too;
- Rolling resistance is noticeably less than in ratchets;
- The cassette is easier to remove;
- More mileage;
- You can change the asterisks individually.
The last plus, of course, is the most significant, and we emphasize it once again: changing the system completely or only one or two stars is a huge difference! Well, there is only one drawback. the original price is higher. However, this again negates the very advantage. the ability to repair, and not buy a new one. Should you opt for a cassette tape? Definitely yes!
What types are cassettes divided into
It is very interesting to know how the stars are fastened on the drum and among themselves. The modern bike cassette is available in several versions. Each of them is good in its own way. Meet:
- Solid milled,
Spacer cassettes are sprockets fastened with separate splines to the drum. For separation between them, plastic spacers are inserted. Parts have a strictly specified thickness so that the distances in the cassette between its elements remain unchanged. The advantage of such a system is that they can be disassembled “to zero.” The disadvantage, however, for aluminum drums is a high torsional load, because from each star the force is transferred to the drum. On the stronger steel counterparts, this problem is not observed. In a spider-type connection, all the stars are put on a single spline. Legs are made in the form of ladders for each asterisk. Power loads are reduced, so this type of cassette should be chosen for aluminum drums. Also, compared to spacers, these systems are lighter.
You can also change only one asterisk to the Spider
On solid milled cassettes, the entire unit is made as one piece. It is fixed on the lower star, which is the slot for the drum. Among the analogues, this is the most expensive option:
- The simplest device due to the absence of additional connections;
- High strength;
Solid Milled Transmission Cell
What about the disadvantages? First, the price will only pay off in an expensive mountain bike. And secondly, the design is very much like a ratchet. And although durability and strength were declared, no one canceled partial wear. And it is impossible to change one or two stars.
The block model is represented by several spiders with two or three stars on each. Small stars are inserted into the reel slot by themselves. Since they are more likely to wear out with your bike, you can change them altogether. Other components on the blocks change immediately in pairs.
Disassembled Shimano block cassette
Diagnostics and care:
- Tighten the wheel hub bearings. In principle, you can NOT remove the mechanism itself, but the bearings are easier to remove when removing the entire device, they are quite small, it is very difficult to remove them.
- Lubricate the system. Sometimes the prerequisite for improper bike operation is not only the lack of lubrication, but also its abundance.
- Replace broken dogs. The reason for the repair of the transmission may be a broken pawl that does NOT catch the wheel mechanism, or a spring that pushes it.
- Sprocket teeth wear. The most common reason. The entire device needs to be replaced. Small diameter sprockets break most often.
- Cleaning from dirt and grass that gets clogged between the stars when riding.
Beginning of disassembling the bushing. removing the cassette retaining ring.
I usually remove the inner ring of the bearing with the locknut with a pair of needle-nose pliers, carefully push the “nose” into the spline of the outer circlip. Hold the sprockets firmly, as if trying to return them in the direction of free play
For Right Hand Threaded Wheel Use the same method to force the hub retaining ring to rotate counterclockwise.
The outer circlip has a right-hand thread. When working with a bicycle drivetrain, always keep in mind the direction of rotation of the pedals, which always corresponds to the direction of tightening. So the sleeve usually spins counterclockwise. If the transmission is located on the right, then the rear hub will definitely have a right-hand thread.
What is a ratchet?
Ratchet. A ratchet mechanism consisting of a freewheel clutch, views and a threaded ring. The design transfers the rotation from the pedals to the wheel through the chain, while simultaneously allowing movement without the need to pedal. It is screwed onto the bicycle rear hub axle thread. If the sprockets wear out, they unscrew and change completely to new ones.
Cassette and ratchets should not be confused. In modern bicycles, they began to use a cassette. a device more advanced than a ratchet. The design consists of stars assembled together, which are put on the sleeve and secured with a nut, and the holes in the middle are equipped with grooves, which it clings to the drum. There are pawls, springs and a ratchet inside the drum. The cassette is easier to remove and replace unusable asterisks with new ones. It can be easily dismantled in any conditions, and the removal of the ratchet is best done on a workbench. This requires not only a special tool, but also significant physical effort. The impossibility of repair is its main drawback. Plus low views and fragility.
It just works. The system has a pawl that engages the rear of the transmission mechanism, at which time a slight crackling sound is heard. From this cod comes its name. If there is no sound, this means that it will pull the chain forward when the pedal does not rotate.
How to disassemble the ratchet?
To repair the ratchet with your own hands, you need a hammer and center punch. Instead of a punch, a large nail or self-tapping screw will come in handy. It is better to disassemble the device on a wheel so that you can hold it.
- The ratchet spins on the wheel. A center punch is inserted into the hole on the Nut, and the mechanism is disassembled by turning it clockwise with a hammer.
- The stars are removed with a Puller and a key. There are balls inside under the nut. There is also a second ball track on the wheel.
- To prevent the balls from scattering, you must put a rag or box.
- The smallest asterisk is unscrewed counterclockwise. The rest are just filming.
Removing the ratchet from the wheel
Now you need to look at the condition of the mechanism, pawls and lubrication. Dogs wear out most often. They can be replaced. A special repair kit is made of dogs and rings. Be sure to use ball bearings. If the balls are black and there are frayed metal particles, then the bearings have broken. Each must be examined. If dents appear on them, it is recommended to replace them.
Next, we collect all the parts in reverse order. The flare nut must be tightened with force, and the backlash for the sprockets of the wheel should be adjusted by dials, thin rings.
Thus, it is much cheaper to repair the mechanism with your own hands and will NOT take much time and effort. And it is necessary to perform such actions regularly so that cycling is pleasant and safe.
Puller and key
Removing a long-established ratchet requires considerable effort. It can get stuck and rusty. In stock There must be special tools, which are a puller and a large adjustable or wrench.
The puller is a slotted wrench for disassembling or installing the ratchet mechanism. It is unscrewed counterclockwise with the introduction of a wrench or adjustable wrench. Ratchet Tools and Cassette Devices are similar, but completely incompatible, do not confuse them.
The rear wheel is removed first. If the ratchet has not been removed for a long time and it is difficult to remove it with a puller, then it is better to use WD-40 grease. It is better to lubricate the threads from the inside, under the stars, and leave for several hours.
When removing, there may be a problem with a lack of effort. Unscrew the stuck mechanism. This problem of lengthening the tool is solved. This can be done with a small tube. Take two bolts 6-8 cm in size and select nuts for them. One is inserted into the hole in the Puller and the other into the hole in the handle of the adjustable wrench. Clamped with nuts. Insert a tube between the bolts. It turns out a lever with which it is much easier to rip off a stuck device.
The difference between a ratchet and a cassette
Do not confuse the bike ratchet with the cassette, as they are NOT interchangeable. Currently, the former can only be found on old and very cheap bicycles. On modern bicycles, a more advanced part, such as a cassette.
The main drawback of the ratchet is its incompatibility with the 15 mm diameter hollow shaft of the new QR15 standard. Loose loading from off-center sprockets can cause local bending on the hollow axis.
In ratchets, the smallest sprocket is NOT smaller than with 14 teeth, and its more modern modification. a cassette. can have even smaller sprockets, with 11 or 12 teeth
On the inside of the ratchet there are ratchet pawls, the floor of which is installed with an external sleeve from an asterisk. The role of the nut holding these two parts is played by the cone, which is the working surface for the ball bearings. Inside there are two bulk bearings, each of which is assembled from balls of the same size.
The hidden part of the ratchet. the inner sleeve. is screwed onto the threaded part of the rear wheel, and to remove it, you need a special puller.
Internal ratchet bushing
The main components of the wheel
A standard bicycle wheel consists of several main parts:
- The bushing is the central part, through which the torque is provided. The interior of the rear hub is slightly more complex than the front. NOT every sleeve can be disassembled at home, some variations without special equipment and knowledge It is better not to touch. And also brakes can be attached to this part;
- Spokes connecting the hub to the rim;
- The rim on which the tire is mounted;
So, if you need to repair the rear wheel of a bicycle or it is just time to service the spare parts, you need to clarify the procedure to be carried out when removing a wheel.
Removing the front wheel from the fork
Removing a wheel is the simplest maintenance procedure for your bike. This is done very simply:
- Bicycle turned upside down.
- Opening the rim brake, remove the caliper from the disc.
- Loosen the fasteners from the fork dropouts.
- Remove the wheels from the mountings.
On dropouts, the mount is nut and eccentric. In the first case, you will need two 15 mm wrenches. with one we hold the nut, with the second we carefully twist it on the opposite side. With the eccentric, everything is easier. loosen the retaining nut and fold the clamping lever.
When to remove the front wheel:
- Replacement of tubes / tires;
- Needle tightening / loosening;
- Bulkhead bushing;
- Rim painting.
Installing the front wheel on the fork is done in reverse order.
The device and installation of the front wheel on a bicycle
Bicycle front wheel. The driving unit, without which it is impossible to imagine a bike, except perhaps a unicycle. The driven wheel, synchronized with the fork, is responsible for the trajectory of the bike and, to a greater extent, the rolling speed. Unlike the rear wheel, the front wheel is simpler in design, but also requires timely maintenance.
A bicycle, like a car, needs regular maintenance, and the front wheel is one such fundamental component that cannot be neglected. Give him a little attention!
What does the wheel consist of?
Bicycle wheels are the most conservative component. Of course, models on cast disks have appeared, all-round wheels are put on track models, but they are in the minority. Still, the majority of bicycles are equipped with spoke wheels.
The front wheel structure is as follows:
- Conventional bushing;
- Connecting needles;
- Rim Protective Tape (Flipper)
- Camera and tire;
- Disc (on models with disc brakes).
The hub. the axial part of the wheel, is an assembly of the central axle, bearings and tapered clips. Cone bearing systems are most often mounted on bushings with an open type bearing. They can also be equipped with a closed bearing or SPEECH.
Rim. supporting structure, metal ring. The rims are mainly made of aluminum, with carbon fiber rims being used on expensive models. In terms of rigidity and power, they are divided into three types:
- Single-wall. the outer and inner surfaces have one line of contact (jumper)
- Double. the inner surface is attached to the sidewalls, compartments from the outer;
- Triple is the strongest and most durable option: the inner wall is also fixed to the sidewalls, but, unlike the double rim, the triple rim has an additional wall in the middle.
Vertical bridges form channels running in the direction of rotation. According to the number of such channels, modern rims are divided into one, three- and five-piece:
Spokes. elements of the connection between the hub and the rim. They perform the functions of securing, distributing loads along the rim and central axis and mitigating vibrations during movement. Perforated rim, each hole is designed to hold one spoke. The number of spokes is set on a bicycle wheel in multiples of four. Depending on the model, their number varies. from 28 to 40 on average.
The number of spokes for the front wheel is usually less than the number for the rear. This is due to the fact that the bulk of the load falls on the rear of the bike, and there the wheel must be stronger.
By the type of section, the spokes are divided into:
- Standard (rolled). constant circular cross-section along the entire length from the sleeve attachment to the tip;
- Aerodynamic (blade-like). elliptical or rectangular profile;
- Variable section (drawn). standard section in heads and tapering towards the middle.
The inner tube is the inner part of the tire that holds the pressurized air inside. Tire. the outer shell, in contact with the road, absorbs bumps, protects the camera. The tire is made of a harder rubber than the tube.
Rim tape, or Flipper, is a rubber lining under the tube to protect it from breakdown on the spoke tips. Dynamic loads force the walls of the chamber to bend, which causes them to be pressed against the rim surface. Without the Flipper, the camera can be pushed into the hole with the spoke tip. This problem is more pronounced on the rear wheel, where the loads are higher, but the presence of a Flipper is mandatory on the front. The torn tape must be replaced with a new one. Proven home-made option. glue the rim with several layers of electrical tape, except for the hole for the nipple.
Bulkhead bushing, rim alignment, tube and tire replacement
The technical condition of the bike directly depends on the serviceability of all its components, including the front wheel. There are not so many problems with him, but they visit regularly:
- Wear of bushing components, grease production;
- Curvature of the rim. “eight”;
- Chamber breakdown, tire cracking.
The hub provides a stationary axle attachment to the dropouts and uniform unhindered wheel rotation. Insufficient lubrication causes increased bearing friction and, as a result, rapid wear. Symptoms. the wheel is loose, pronounced backlash, difficult rotation, crunching.
So how to disassemble the bushing:
1. Remove from dropouts (see above).
2. Loosen the retaining sleeve nut. To do this, you need two 17 mm wrenches. with one firmly fix the nut, the second will twist it counterclockwise to the left.
3. Screw on the cone. For the hookup, you will need a key for 14, then it can be easily twisted by hand.
4. Pull out from the opposite side. Carefully remove the left bearing from the housing cavity and pull the right one off the cone.
Inspect everything carefully, especially the bearings. Damaged parts must be replaced with new ones.
Bushing Cleaning, Lubrication and Assembly:
- Blow dirt out of an empty case.
- Using a narrow brush or cotton swab, apply a thin layer of lubricant to the inner walls of the sleeve.
- Wipe the cones and bearings with kerosene and let dry (if Installing the same components).
- Lubricate here, bearings and cones from the inner sides, which adjoin the bearings. I do not regret lubrication for bearings: the more, the better. Gently wipe off excess with a clean cloth.
- Put the right bearing on the Corresponding cone with the side as it was before.
- Move it into the bushing and install the left bearing on it.
- Gently screw in the cone. Its surface should touch, but not the bearing clamps.
- Tighten bushing with nut.
- Place the wheel on the dropouts and fix.
We check the work of the bushing. we spin the wheel with force. If everything was done correctly on the bulkhead of the hub, the wheel will spin easily and silently. If the rotation is difficult or the bushing is “moving” in the axis, it is necessary to loosen or tighten the left cone. Perhaps, for an accurate result, adjustment will be required several times, the main thing here is not to rush.
Eights are the most annoying problem with wheels. It arises equally from the front and from the back. The front eight delivers less discomfort than the rear, but still, driving on a crooked wheel is not high. Consider how to quickly fix defects in a bicycle rim. To work you need a universal spoke wrench, it looks like this:
Repair of the figure eight is done as follows:
- Determine the maximum wheel bulge. In this area, pull the knitting needles at an angle that is a multiple of 1 turn.
- Loosen two knitting needles at the edges by an angle, half the amount at which you pulled up the central knitting needles.
- Pull the next outer needles to an angle half the size, by which the two needles were weakened.
And so on, it all depends on the amount of curvature. The picture shows a diagram of the elimination of a 7-spoke eight.
If the curvature is between the needles, do this:
Replacing the chambers is easier than repairing rim defects, but also more often required. In order to correctly and easily remove and install tires, it is advisable to use special plastic mounting.
How to disassemble a tire:
- Remove the wheel from the fork mountings.
- Bleeds air from the chamber (if we only change tires).
- Unscrew the protective cap from the nipple and push it down slightly.
- On the opposite side of the hook two.
- With the third assembly, hook the bead on the sides, until the tire comes off the rim. Now you can get the camera.
Assemble the tire as follows:
- Pump up the camera a little so that it straightens.
- Put the camera in the tires.
- Use the arrows to select the correct direction of the tire.
- Insert the nipple into the rim hole.
- Push the tire beads into the rim from the nipple side to the opposite end. When pushing becomes difficult, use the Edger.
- Pull the nipple tube upward (for Schrader).
- Check that the beads are completely in the rim and put the wheel on the bike.
The front wheel on a bicycle is a simple unit, which you can independently service at home with your own hands: disassemble and assemble the hub, change the tire and eliminate distortions on the rim. Serious problems. broken spokes, cracking of the hub body. will require the help of a specialist.