We remove the asterisk ourselves
Turn the bike over and place it on the handlebar and saddle.
First of all, we remove the wheel by unscrewing the fastening nuts.
Children’s bicycles are usually repaired, as a rule, by dads, and they have enough strength to fix the largest sprocket with a whip and put a wrench on the puller to unscrew the spline nut. Everything is unscrewed in the direction of the idle wheel and at the same time a small crunching sound is heard, do not be alarmed, this is due to the shape of a small asterisk.
By unscrewing the nut, remove the cassette, taking into account that there may be intermediate washers between the small sprockets, instead of gaskets. To replace the sprocket you need a set of tools.
When disassembling this entire structure, carefully fold all the parts so that they lie in the sequence in which you removed them, otherwise difficulties will arise during assembly.
After removing all the sprockets and the cassette, the protective plastic ring is removed last. Inspect all removed parts carefully, replace worn ones, clean and lubricate so that after assembly the assembly runs for a long time.
The sprocket cassette is assembled in the reverse order. The chain is put on, the rear wheel is spun, the device turns over and it is again ready to surf the roads bringing joy and pleasure from the movement.
Bicycle rear sprocket
A bicycle is a means of transportation, driven by the physical strength of a person. This is how you can describe the essence in technical words. In fact, he is a friend from childhood. As soon as we start growing up and understand something, we drag our parents to the place where we can choose a bike and shout: “Buy it !!”, in the end we proudly roll the novelty home, while we still don’t suspect that any equipment needs care and that it might break. Even an old bike can still serve.
The most common question about servicing the bike and the rear hub (excluding the device, ratchet and sprockets) is “How do I remove the sprocket from the rear wheel of a speed bike?”
It often happens that the hub needs lubrication or the rear wheel sprockets need to be replaced. The repair process is easier if the cassette is removed. Thus, things will go faster and more accurately.
When you need to replace your rear bicycle sprocket
An inexperienced user may confuse a sprocket and a ratchet, but the difference is that the cassette stars have a minimum diameter of 11T, while the ratchet has a minimum diameter of 14T. To replace the rear sprockets of the bike, you must remove the entire cassette completely.
The ratchet of the rear wheel of the bicycle has several driven stars, which are connected by a freewheel hub. The ratchet is considered not a very durable and reliable component; axle breakdowns often occur due to imperfections in the design. The ratchet can be removed for repairs in the same way as the cassette.
The efficiency and functionality of the bike depends on the rear wheel hub. The part has several components. If the stroke is heavy, then there is probably a problem and the cone is damaged. To eliminate malfunctions, unscrew the nuts with a wrench and remove the wheel.
When regularly inspecting the technical condition of the transport, pay attention to the bushing taper, clean and lubricate parts and bearings. This detail is very important, it organizes the transmission of the transmission to the wheel from the pedals, as well as several other important tasks.
How to remove a ratchet from a bicycle wheel?
In order to adjust the bearings on the rear hub, in order to replace a worn sprocket, and sometimes to replace a broken spokes in the rear wheel, it is necessary to remove the cassette with sprockets. This is not so difficult to do. By and large, the algorithm of actions is the same as with a separate asterisk.
How to remove the rear sprocket?
- key of the right size.
First of all, remove the wheel. Turn the bike upside down with the wheels and unscrew the nut on the axle with a wrench. In some cases, for example, a sports bike or mountain bike, you need an eccentric clamp. Simple models do not require a special approach and tool.
The rear sprockets are attached to the ratchet with a special nut (slotted). This very nut must be unscrewed with a puller and a wrench. The latter must be appropriate in size. Unscrew the nut clockwise and use the whip. Requires to insert a puller into the spline nut in the rear sprocket of the bike.
We carefully put the whip on a large diameter sprocket. Holding the cassette, we rotate the puller with the key. This requires some effort. After unscrewing the nut, remove the cassette. The rear sprockets of the bike can be positioned independently of each other on the ratchet. It is required to remove all parts, small sprockets, washers, carefully and carefully. This is to avoid confusion of elements. Then the cassette and plastic ring are removed. After completing the replacement of worn parts, all components, including the sprockets, are assembled in order.
The nut is tightened with a wrench and with the application of maximum efforts, but the main thing is not to overdo it and tighten the bushing cone not too much.
Disassembly and diagnostics of this part is carried out after separation of the cassette. It is best to start the process on the left side. Next, the boot, locknut and cone are removed. Then you can find washers, the number of which depends on the type of bike.
It is very important to remember exactly the location and order of finding all the parts. Now the stage begins in which the cone is gently unwound. If the grease is in poor condition, then it is necessary to remove the bearings and inspect them. The presence of rust, dirt and other troubles indicates the replacement of parts.
With this option, good parts need to be put in place before lubrication. With a careful approach to work, the bike will function properly and accurately. Removing the bushing and other parts is not difficult, but it is important to remember the order in which they are located.
Varieties of bicycle cassettes
A set of rear sprockets on a bicycle is called a cassette. Cassettes are available in 6, 7, 8, 9, 10, 11, 12 speeds. The cassette with 6 speeds is placed on children’s bicycles, 7 speed, on budget, walking bicycles. Cassette with 8 sprockets, matches the 24 speed transmissions found on mid-range bicycles, 9-12 speeds on mountain and racing, sports bikes.
The large number of stars allows you to adjust the gear ratio for more comfortable pedaling, the smaller the chainring, the greater the rider’s speed. If the switch is set to a large star, then you can easily climb the hill.
A set of sprockets for 6-7 is in the form of a ratchet, which is screwed onto the bushing and cassettes, which is put on the bushing drum and fixed with a nut. I change the cassette when obvious tooth wear is visible and the chain slips.
The text was prepared by Roman Borisov. Published: May 30, 2020. Sources: uznayvse.ru, yvelo.ru, mighty-sport.ru. Headings: Microrecords, Repair and maintenance.
How to disassemble or reassemble the rear wheel of a speed bike
Removing the wheels from the frame is part of a mandatory bicycle maintenance procedure. Sooner or later, the wheel of even the most advanced bike will present surprises in the form of deformation of the rim, damage to the spokes, a burst tube or even the entire tire, as well as wear of the sprocket system for the rear wheel.
Experienced cyclists welcome self-repairing wheels, and it is no coincidence: it’s cheaper, and you will gain skills. You can also go to a good workshop, where the problem will be solved, perhaps faster, but not free of charge. over, the service is hardly located under the windows of the house, so the bike will have to be dragged, which is not very pleasant. To avoid this, it is better to tinker a little yourself, especially since there is nothing complicated about the wheels. Today we’ll talk about how to remove the rear wheel from the bike, repair it and assemble it correctly.
When to remove the rear wheel
It is unlikely that the idea of unscrewing the chassis from the bicycle frame would just come to mind, unless, of course, a person specializes in bicycle dismantling. But this is a completely different case. Dismantling the rear wheel will be required if the following problems are observed:
- noticeable damage to the rim;
- complete wear when a wheel needs to be replaced;
- a flat tire or a burst tire;
- bulkhead bushing.
This includes the planned replacement of the rear sprocket system and chain.
How to Repair, Repack and Adjust a Bicycle Hub
Before removing the bike, turn it over and place it on the saddle and handlebars. It is better to remove awnings in the form of a mirror, a bell and a lantern in advance so as not to damage them under the weight of the frame. V-brakes are first released and disassembled, otherwise they will not allow the wheel to be pulled out freely. With disc models, everything is easier. you can immediately remove the wheel.
I must say that the removal process itself consists only in unscrewing the eccentric or unscrewing the fastening nuts from the axis of the bushing, who has something. If the mount is an eccentric, simply unscrew the handles and twist the wheel. The nut fastening is loosened with one or two wrenches.
Usually one wrench of the appropriate size is enough, with which the nuts are removed one by one. If the hub axle turns, then the nuts are unscrewed simultaneously in different directions. It is recommended to use open-end wrenches or box wrenches. The adjustable version is undesirable, as its thick horns “eat up” the corners of the nut due to loose fit and sliding.
Removing the cassette and bulkhead bushing
A hub is one part of a bicycle wheel that requires periodic maintenance. On average, you need to look into it once every 2000 km of run, in terms of time it is 2-3 months of active driving. If the wheel is already squeaking and there is a decrease in the efficiency of rotation, in other words, the great rides worse, then it’s time to remove it and inspect the hub.
The main problems with the bushing are backlash and insufficient lubrication of the bearings. Due to a violation of the fit or increased friction, the parts begin to wear out rapidly. If the wheel has not been serviced for a long time, the bearings may crumble altogether. To gain access to the bearings of the hub, you will need to temporarily get rid of the rear sprockets.
The reverse gear is removed using a puller and a so-called whip. Removing the cassette is a short-lived affair, but it will take a lot of effort to unscrew it from the wheel. In stages it looks like this:
- The stripper is inserted into the cassette nut.
- The whip holds the large star of the system so that it does not turn.
- With a wrench, the puller rotates, unscrewing the slotted nut.
- We remove the small stars that are installed on top, carefully fold them to the side along with the washers, and then remove the cassette itself.
Before disassembling the hub, you should slightly loosen the spoke tension. This can be done using a round key with knocked out holes for different diameters of the knitting needles. You need to loosen a little, a quarter of a revolution is enough. If the sleeve needs to be replaced, the spokes must be unscrewed enough to easily pull it out of the engagement.
A complete bushing replacement is required if both the axle and the bearings become unusable. However, often when the bushing is jammed, the axle is in normal condition, it is enough to change the bearings. Often, both will still serve faithfully if they are well lubricated. Proper lubrication will prevent parts from wear under dynamic loads.
The bulkhead of the axle part of the wheel is associated with cleaning the axle and bearing balls from dirt. The removed parts must be temporarily placed in a solvent, then allowed to dry, lubricated and reinstalled. Bearings in a skewed position must be adjusted by returning them to a straight position. However, during the backlash, the parts are already faulty, so replacement is the best option.
Replacing the bike camera
To remove the tire and remove the damaged chamber, it is necessary to remove the remaining air: the cap is unscrewed and the wheel is lowered by continuous pressing on the nipple. If there is no air in the tire, which is more often the case with punctures, then simply unscrew the cap.
To remove the tire, you need special paddles. Of course, you can pry the camera with an ordinary screwdriver and even a knife, but it is better to have a professional tool. With the help of assemblies, the tire is pushed on from the side opposite to the nipple. As soon as it starts to tighten, you need to pry the sides a little further, until a sufficiently free part of the tire is formed, and it can be safely pulled off the rim.
You need to tighten it very carefully so as not to damage the rim, you should not use too much force. When the tire is removed, remove the damaged camera and install a new one. The nipple is threaded into the hole in the rim, then the chamber is evenly distributed around the circumference.
Attention! The camera must lie flat, without kinks, otherwise you will have to reinstall it. There must be a flipper at the bottom of the rim to protect it from the spokes. If it is torn, you need to install a new one or get by with two layers of thin electrical tape.
From above, the outer part of the tire is put on the rim, this time from the side of the nipple. When installing the tire, the correct direction of the tread pattern must be taken into account. Usually, arrows are drawn on the tires, and in the upside down state of the bike, the forward direction is backward in the lower position. However, the rear wheel of a speed mountain bike is easy to go wrong, thanks to the cassette on the side. After mounting, the camera is inflated.
Assembling and installing the rear wheel on the bike
A quality wheel repair is not only about disassembling, replacing, lubricating or adjusting. At the last stage, all this chaos must be collected in reverse order. All parts of the bushing mechanism are placed in the drum and carefully secured with locknuts. The drum is pushed onto the spokes, after which they must be tightened by the number of revolutions by which they were loosened.
Tightening the spoke nuts is done in the opposite direction to loosening. Here you need to remember the direction of loosening in order to tighten correctly. If the drum dangles, then you need to tighten the spokes harder.
The cassette is put on the sleeve in the following order:
- main stars;
- single stars, small stars;
- tightening the cassette mechanism with a whip.
All that remains is to put the rear wheel on the frame. A chain is put on one of the stars, and the wheel is inserted into the grooves of the frame. To top it off, all that remains is to tighten the nuts or eccentrics on both sides. After assembly, you need to twist the pedals and see if the chain runs normally in the stars. We turn the bike over and begin to ride calmly!
Anyone who actively rides a bicycle will have to deal with wheel problems one way or another. Despite the ease of maintenance, the wheel can be time-consuming at first. However, if you remember how important wheels are to a bicycle, it turns out to be not so much. What’s more, with experience, a wheel bulkhead will take minutes.
What are the bushings by location?
The front ones, with which there are no problems, since they differ in a simple device, and the rear ones, which are responsible for the cassette and the ratchet, which they carry, in addition to performing the functions of holding and rotating the wheels.
Both cassette and ratchet are required for gear shifting. In the first version, it consists of a set of 8-11 stars. Worn sprocket can be easily replaced without removing the hub.
- Disc hydraulic brakes on a bicycle and their adjustment
- Device, maintenance, disassembly and assembly of the rear bicycle hub
- V brake brakes and their secret of popularity
In the second, it is a monolithic structure that cannot be disassembled and is formed by 5-7 stars. It is clear that the first option is preferable, which can withstand a rider with a large weight and is characterized by high reliability.
Separately, there are rear planetary hubs (Shimano SG-3C41), which have a mechanism inside that allows, even while standing still, to switch speeds (from 3 to 5).
What are the bike hubs?
Only a high-quality rear hub will provide minimum friction for rotating wheels, improving rolling. In addition, its use will increase the resource and will not create problems when riding bike bikes in wet weather.
Rear hubs differ in characteristics associated with:
- the location of these parts;
- compatibility with a certain type of brakes;
- the material used for the manufacture;
- suitability for a certain number of knitting needles;
- weight and size.
Material for bushings
Steel bushings are the heaviest of all. They are used in budget models. They are susceptible to corrosion, unlike more expensive and non-rusting aluminum.
Division of bushings by application
For road models and high-speed (touring, mountain, road) there are certain types of bushings. For the first option, the choice is bushings, the mechanism of which has a free play and one driven sprocket.
On-road models are equipped with drum brakes. Suitable for the rear wheel of a high-speed bike, a hub with a free wheeling, no braking mechanism. In addition, they are divided into cassette and ratchet.
Maintenance of the rear wheel hub of a bicycle: repair and its features
Winter is in full swing, which means it’s time to prepare bicycles for the summer season. The main problem is the bike’s rear wheel hub. Its repair is the most difficult. Not everyone can assemble the rear wheel hub.
Material for making bushings
Most often, there are rear steel bushings, less often. from an aluminum alloy, even less often. titanium (Shimano XTR, for example).
If there are no questions with the front bushings, then with the rear ones, which differ in the presence of a seat for sprockets, there are more than enough of them. In the models produced earlier, the sprockets were screwed onto the threads and were solid.
But this design is now a thing of the past, since threaded connections have enough disadvantages:
- the ability to strip the thread during installation;
- uneven wear on stars and ratchets;
- low rigidity and low strength;
- significant energy losses
True, they are installed in separate models, giving preference to cheapness, but, in general, they are becoming a thing of the past, giving way to cassettes. The spline connection of the hub and cassette offers the following advantages:
- light weight;
- reduction of losses due to the ratchet mechanism installed inside the splined drum;
- an increase in rigidity due to a greater distance between the bearings and an increase in reliability (it is not realistic to tear the cassette off the slots)
- ease of installation;
- interchangeability of individual sprockets without dismantling the cassette.
In addition to the ratchet mechanism, the design of which is very simple and represents spring-loaded pawls, teeth clinging to the ratchet, thereby transmitting torque from the sprockets to the wheel, there is another type of rear bushings. roller.
This is how the classification of these parts looks depending on the type of sprocket attachment. But, the hubs also differ in their attachment to the bike frame:
- using eccentrics.
The latter are less preferable for extreme types of driving, since they do not “hold” the wheels well enough. For these bikes, there are MAXLELite and MAXLE eccentrics, which do not have a clamping nut on one side.
There is a thread on the axle instead and on the dropout of the bike fork there is a corresponding threaded hole. For installation, thread the Maxle eccentric through the threaded hole, twist the axis in it, then clamp the entire axis with a special eccentric, which is a pipe cut into 4 petals. a cone, which ensures reliable fixation when clamping.
Designed for disc brakes only. Maxle Lite features material and half the weight
Before disassembling the rear wheel of a bicycle, installing it on a special stand, or any other component of the vehicle, it is necessary to study its structure.
- knitting needles;
- tube or tire that must have the correct pressure.
The device of the rear wheel hub of a bicycle is quite simple: it is attached to the rim with spokes (from 12 to 48 pieces).
Wheel size is determined by the outer diameter, which ranges from 14 to 29 inches. Mountain bike models are more often equipped with 26-inch wheels, while hybrid or touring models are equipped with 28-inch wheels.
The rear wheel of a speed bike is not spoked. Instead, a solid disc is used for increased rigidity. This design is less resistant to oncoming air flow, but has increased windage, which makes it difficult to ride in a crosswind.
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 are most often equipped with rims that resemble a box in cross-section. Thanks to this shape, the wheel is protected from damage when hitting a hard obstacle.
Bicycle Freewheel Disassembly/Assembly
Steel or aluminum alloys are most often used as a material for the manufacture of rims. Steel rims are cheaper, but they are heavier and less resistant to corrosion. Carbon is considered the most modern material, but the price of such models is very high.
HOW TO PUT THE WHEEL IN PLACE
To do this, you need to make sure that the chain fits on the sprocket as expected. Therefore, first put on a chain on the sprocket, and only after that we put the wheel on the mount. If you have gloves, put them on, otherwise it is very difficult to wash your hands after such an installation. Slip the wheel into the mount so as not to confuse the rotation.
It is required to fasten the wheel firmly enough so that it does not fly off when driving.
Put the brakes back in place, as it was the wound, this means the rim brakes.
It happens that it seems as if the chain is twisted or is not properly placed on the sprockets, it gets tangled. Just spin the chain back and forth using the pedals, or by hand, without removing the wheel, the defect should be corrected. If you move the gearshift mechanism located in the chain mechanism aside and put on the released chain as you wish.
After all procedures are completed, perform a test drive. Check how the brakes behave, whether the patch is missing, and then you can safely go further on your business.
How to unbuckle a bicycle wheel
We carry out the process of removing the wheel. How to do it mentioned above.
Now you need to lower the wheel, because without this, you will not be able to remove the camera. We find the cap that is screwed onto the tire nipple, turn it over in the opposite direction and insert it into the nipple and start twisting.
If you do everything correctly, you will hear the sound characteristic of a descent wheel, a hiss of air bleeding through the opening.
After the air is deflated, take the beads or screwdrivers. With the help of one we pick up the tire located near the nipple, and we drag it out, the screwdriver itself, attention, we leave it inside. Do not be distracted, because you can break through the camera, be especially careful.
Now we take the second bead (screwdriver), and a little further from the nipple we pry the tire. Pull it gently outward. So, step by step, making movements in a circle, you will remove the tire, be it a rim or a disc.
The lacing is the order in which the hub, rim and spokes are locked. It can be radial or cross. Radial provides for the installation of the hub without crossing the spokes with each other. Crossing the needles occurs.
To maintain the good condition of the mechanisms of the bicycle, it is required to periodically service it. For the rear wheel, similar work is done as follows:
- the body is tightened;
- 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, the rear wheel must be constantly adjusted to make the ride comfortable.
We disassemble and assemble the wheel: the device of the rear hub of the bicycle
Most modern bicycles are two-wheeled. The rear wheel of a bicycle, the device of which will be discussed below, is most often the driving wheel and begins to rotate under the action of the movement of the chain.