How To Replace The Rear Axle On A Bicycle


This component of the rear hub design acts as a bonding shell for other functional devices. The main requirement for the body is a high degree of rigidity, since the hub is subjected to significant torsional loads during driving.

The rear wheel hub of a bicycle can be protected by a stamped or cast body. The most reliable high-strength housings are produced in the first way.

How To Replace The Rear Axle On A Bicycle


The rear hub of a bicycle must be equipped with bearings with a dust cover. Only in this case it will be possible to forget about their maintenance and replacement, dashed off on a bike more than 10,000 km. Frankly low-quality bearings will make you endure unpleasant sounds and suffer from wheel play after the first ride in rainy weather, not to mention winter. Reliable dirt protection is represented by various seals, which prevent contact of the lubricant with the external environment.

Currently, bulk and industrial bearings for rear bushings are distinguished. The difference is that the play in the wheel can be eliminated by performing the usual adjustment of the bulk bearings. If there is a similar problem in the case of industrial bearings, most likely they will have to be replaced. Therefore, the rear wheel hub of the bicycle should be selected, Based on the type and reliability of the bearings.

The main parameter of the rear hub axle is its length. To select the hub according to the axle length, you just need to measure the distance between the opposite outer nuts on the corresponding bike frame mounts.

Bicycle rear hub: device and assembly instructions

The rear hub of a bicycle must always be in good condition, because it is it that determines the smooth running of a two-wheeled vehicle. According to many cyclists, the ride quality of a motorcycle depends largely on the type and mechanical characteristics of the frame. However, in practice, the defining moment here is the state of the undercarriage. bushings, carriages, chains, and other systems.

According to the compatibility with different types of brake systems, there are several SEPARATE types of rear hubs:

  • For disc brakes;
  • For roller brakes;
  • For rim brakes.

Of course, the more complex rear hub of a bicycle, designed to connect to a disc brake system, can easily be used to assemble a wheel with rim brakes, but not vice versa.


They are specific annular protrusions that are contained on the rear hub body. This element is used to connect with the spokes of the wheel. Flanges contain special holes where spokes are inserted when dialing.

The main requirement for flanges is a high strength index. Based on the insignificant size of the part, it is enough just to imagine how much increased loads fall on its fate. After all, a third of the structure of the bicycle, together with the cyclist, is located exactly above the area where the rear flanges are located.

Design differences

The rear hub device of a mountain bike has some differences from the design of the chassis for road bikes.

Bushings for road and road bike models have oil seals. special seals designed to protect bearings from contamination. Often glands are integrated into a single piece with tapered elements.

Bicycle rear hub “Stealth”, as well as other common models of mountain and off-road bikes, in addition to oil seals connected to the cones, it often has rubber anthers. The presence of such elements helps to increase the protection of the chassis from dirt, all kinds of debris and dust.

Unlike the road bike category, mountain bikes are designed to ride in the most rugged terrain. Naturally, the use of additional protection for the rear hub mechanism proportionally increases the weight of the two-wheeled vehicle and reduces the ease of movement. That is why the assembly of the rear hub of a road bike is carried out by most manufacturers without installing these elements.

We should also consider the design features of bicycles with disc brakes. Here mechanisms are used, the flanges of which are connected to the brake discs.

Differences are also present in the methods of connecting the ratchets to the hub with the cassette mount. Most of the common domestic bike models contain hubs with an integrated ratchet. In contrast, the rear hub of a speed bike is usually a screw-on type of ratchet.

How to assemble a rear bike hub?

When starting to assemble the mechanism, you need to take into account the fact that the left and right ends of the wasp have some differences. The right cone is firmly connected to the axle, additionally secured with a lock nut and therefore never dismantled. The system is adjusted by configuring the position of the left cone.

When trying to figure out how to assemble the rear hub of a bike, the main thing is. DO NOT confuse the side to be installed with the right cone. It is much easier to make a mistake here than in the case of a front wheel assembly, where both sides of the mechanism look identical.

To avoid troubles, Connecting the elements of the rear hub into a single whole during installation, the following sequence of actions will allow:

  • To begin with, the bushing body, ratchets and the surface of the cups for mounting the system are cleaned of dirt, remnants of old grease, after which a new grease base with a thick consistency is applied.
  • Using tweezers, the balls of the bearings are placed in the right place and pressed into the layer of grease, the amount of which should be sufficient so that the balls do NOT roll back.
  • From the side of the ratchet, it is installed here with a right cone. The operation is carried out carefully, as there is a high risk of pushing the bearing balls out of the bowl.
  • In conclusion, the left cone is screwed on almost all the way, but it is not tightened. Washers are screwed on in the correct sequence, after which the locknuts are attached.
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At this point, the rear hub is considered practically assembled. The only thing left is the installation of rubber boots. However, it is advisable to do this only after the final adjustment of the chassis.


The rear hub of a bicycle includes the following structural elements:

  • Housing;
  • Flanges;
  • Here;
  • Bearings.


After examining the internal and external design of the rear hub of the bicycle, it is recommended to pay attention to the wide range of sizes of this system. The presence of some differences in parameters is due to the use of hubs on various types of bicycles:

  • Track model. 10×120 mm;
  • Road bikes. 10×130 mm;
  • The bulk of the common mountain models.10×135 mm;
  • Downhill bicycles. 12×135 mm;
  • Professional class models “cross country”. 12×142 mm;
  • Models of bicycles for freestyle, extreme sports. 12×150 mm;
  • BMX bikes. 14x110mm.

Specific features

In the majority of cases, the rear bushings are asymmetric, since a cassette or a rear sprocket should be located on the right side of the mechanism. Compared to the left flange, the right flange is closer to the center of the axis. As a result, on the right side of the spoke is slightly shorter.

There is a special type of planetary bushings. The internal structure of such products contains a mechanism for shifting gears. Only one star is installed on such systems. The bushings of this plan can be operated without installing a chain tensioner.

Padding the cone

This situation is the opposite of the previous one: The flare nuts are tightened too tightly, which causes excessive friction in the bushings and the wheel loses roll. In this case, adjustment of the cones is also required, and all actions are similar to those described above.

The most common problems and how to fix them

If the locknuts of the bushing are not tightened sufficiently, then during the rotation of the wheel, the rear axle beats into the bearings. As a result, cavities appear on the tracks of the cones, and the balls are deformed. If the backlash is NOT removed in time, then chips will form on the cones and the inner surface of the sleeve. In especially advanced cases, the balls can even jump out of the tracks and begin to rotate inside the bushing, grinding down and destroying the hubs, then you will have to replace the entire unit and re-spoke the wheel.

To avoid backlash, it is necessary to correctly adjust the cones. To do this, gradually tighten the flare nut, trying to find a condition in which the wheel rotates freely without beating. When the correct position is found, lock the cone with a locknut. When the cone is locked, it often starts to rotate, and the correct position is lost, so you can clamp the right end of the axis in a vice.

What happened to him?

Yes, everything is simple, according to the owner, “After driving onto the curb, I felt the wheel began to wag strongly.” Indeed, the rear wheel wobbled to the point of impossibility. What have we started to do? We got out the camera. Two keys and forward!

What keys should I use to disassemble my bike? We used two wrenches. adjustable and a standard open-end wrench for 15. Look at the following photos of an open-end wrench. This is a standard wrench from a bicycle set for 14 It is convenient because it is thin and it practically regulates the bearing clearance. What we did was cut it a little to a size of 15 mm. But not for the entire length, but only for one centimeter. It turned out a key for 14 and 15. Very convenient, plus weight savings in the bag.

So, let’s remove the wheel. Some wheels are eccentric and some are bolted. Our client was bolted, unscrewed the bolts, carefully bent the caliper and removed the wheel.

Bicycle Rear Hub Maintenance

If you ignore the need for periodic maintenance of the rear hub of a bicycle, then the life of the “iron friend” can be greatly reduced. Experienced cyclists know what signs will indicate to disassemble / lubricate / reassemble the rear hub immediately. This process is NOT difficult, but you need to do everything in a certain sequence.

Back here

The rear of the bicycle is a threaded rod rigidly fixed in dropouts, which does NOT transmit torque, but at the same time carries the main load when the bicycle is moving. It is usually made of steel, titanium or aluminum alloy and is an integral part of the bushing.

Depending on the type of attachment, the axles can be hollow or solid. Hollow ones are used in conjunction with eccentric braces to facilitate wheel mounting and dismounting. Such wasps have more rigidity and less weight.

Another way to fasten the wheel is to fix its axle in the frame stays with special nuts. For a frame with horizontal dropouts, it is more suitable here on nuts because of a more reliable and durable wheel attachment.

Some mountain bikes and cyclocross bikes use a thru axle with a threaded end. These wasps are part of the frame design and are usually supplied with it.

The thickness of the rear axle depends on the type of bike, and its length is determined by the distance between the dropouts of the frame stays. In some models of bushings, the diameter can be changed using special adapters. The following wasps are usually used (the first number is the diameter, and the second is the length):

  • 10 x 135 mm. used in most modern bicycles;
  • 10x130mm. Mounts on Road Bikes;
  • 12 x 150 mm. bike wasps for downhill and free ride;
  • 10 × 170 mm. such wasps are placed on fat bikes;
  • 10 x 120mm. Suitable for speed track bike.
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On bicycles for extreme sports of the High End level, special wasps of increased thickness can be used, which have increased strength.

We work with the inner space of the sleeve

After they have removed it, you need to carefully examine it. As a rule, this part of a bicycle wears out very rarely, but in any case, you will need to thoroughly wipe it off from dirt and dust. This is done with a dry cloth, but in some cases (with heavy pollution) gasoline can be used. So, we wipe the left cone and examine the right one for fastening strength. Only after the walls of the wasp are completely dry (if gasoline was used for processing), you can apply new lubricant to it.

Note: in no case should you use chain lubricant or some other lubricant for the rear hub of the bicycle. you will need to purchase a special tool. For bearings, buckets are often used. this lubricant will be the most suitable. It is not worth applying too thick a layer of grease. it, during the operation of the bike, will be squeezed out and actively absorb dirt, which leads to rapid wear of the part.

DIY bike repair: rear hub

Of course, to care for your bike, you need to understand how it works. Of course, in the structure of the iron horse there is a lot that is complex and incomprehensible at first glance, but they do not lead to close their eyes to this. You need to look at the bike from different angles. Today we will NOT talk about the whole bike in general, but we will focus on what is in the area of ​​the rear wheel of the bike, in particular, on the axle.

The bike doesn’t last forever. change in 10 minutes!

Good day to all! One of these days a very interesting bike came to us for repair! But, more precisely, NOT the bike is interesting, but interesting is what happened to it. The bike was an old one of two Ukrainian-made “Ardis” suspensions.

A little about the bike. a regular steel bike with a rear shock absorber. Features. Build quality is much better than current bikes, rear shock has a protective cover, Tektro rear disc brake.

Crackle or noise inside the hub

Noises, squeaking and crunching noises signal that your bushing is about to be serviced. And this should be done as soon as possible, otherwise everything could end very badly. First you need to disassemble the bushing, change the lubricant and check the parts for defects. Defective components must be replaced. If after all this the problem remains, then it is worth consulting a specialist. It is possible that it arose due to the poor quality of the sleeve itself, and you will have to put a new one.

The rear hub of a bicycle is a very important and often underestimated element of a bicycle, but it is subjected to increased stress. Sand, dirt, microscopic debris and dust are abrasive and destroy metal. Failures of the mechanical part of the rear wheel require expensive repairs or even replacement of the entire unit, so timely and correct maintenance of the hub will significantly extend the life of your bike and help avoid unnecessary expenses.

Here’s a bike

The hub of a bicycle is a very important part of a bicycle wheel, which allows the wheel to rotate freely around its axis. The quality of the hub depends on the speed of the bike, and, accordingly, the speed characteristics. In addition, the better the hub, the less energy the cyclist will spend on the same kilometer of the traveled distance. In this article we will look at the front hub design and the types of existing front hubs.

The front hub is subject to noticeably less stress than the rear hub, which makes it more compact. Additional equipment is not provided, except for the disc brake rotor (depending on the model). Bushings differ in materials and manufacturing technologies, device and purpose.

Bicycle wasps are integral parts of a bicycle and belong to the nodes that are subjected to constant stress. That is why special attention should be paid to their condition. Depending on the type of bike and the conditions of its use, they come in different sizes and differ in their design features. A high level of strength is achieved thanks to the metal from which they are made, often steel.

The bicycle is an integral part of the hub and, together with it, is responsible for the level of load that the wheel and bicycle can withstand, in general, for the ease of movement and the immediate reliability of your favorite vehicle. Only correctly selected and, in turn, adjusted wasps can guarantee a safe and comfortable ride.

A spare part for the rear wheel, in structure, is somewhat different from the front one and is more complex, due to the installation on the rear hub of the freewheel mechanism and the sprocket block. In turn, the rear one can withstand a great load force.

Mountain Bike Wasp Repair

Of course, there are situations when something in the wasp breaks. Fortunately, these situations are NOT desperate. If something breaks, and you still do not understand in which direction you should turn the Necessary nut and where to put the cones. the Internet to help. And we, in turn, will help you navigate the difficult repair business.

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What should be considered when renovating? First of all, you need to understand that everything related to the rear bicycle axle is a very delicate matter, which means that you need to approach it carefully so as not to make it worse.

It is important NOT to lose even a single detail. Even if you lose a small nut or cone, it will be difficult for you to finish repairing the wasp without them. The first step is to remove the rear hubs of the bike, as well as the block from the sprocket. Of course, when removing it, it is better to put the bike on the side where this block is not. After you remove the rear sprocket block, you will need to remove the bearing ring. Everything should be in order, you can see for yourself when, after disassembly and removal, a bunch of small details appear in front of you. Therefore, it is extremely important that every little thing has its place.

Here is QR

QR or Quick-release (from the English. Quick-release). the simplest eccentric, which can be found on budget bicycles. These eccentrics are only installed on bicycles with split dropouts. Due to the small axle diameter of 9mm and 10mm, respectively, for the front and rear wheels and the diameter of the eccentric itself of 5 mm, their rigidity is appropriate, but this is not critical for normal riding. Such an eccentric fulfills its purpose 100% and allows you to quickly remove and install wheels without problems. Found only in 100mm and 135mm sizes for the front and rear wheels respectively.

How to sort out the front bushing on bulk bearings

If you notice any extraneous sounds from your bushing or a noticeably deteriorated roll, or maybe a little backlash, this means it’s time to sort out the bushing.

To begin with, let’s figure out the device of the sleeve. Above is a schematic drawing of the main components, among them:

  • Here. And the part that secures the wheel to the frame and around which it rotates;
  • Cone. By tightening the cone, you eliminate wheel play;
  • Sleeve. The very body of the sleeve with cups for bearings inside;
  • Bearings. Balls that allow the axle to rotate inside the hub;
  • Lock-nut. Prevents the cones from spinning.

The sleeve can also contain various spacer washers and anthers.

To disassemble the bushing you will need:

  • Open-end wrenches of a suitable size (one of them must be thin enough to fit on the taper)
  • Bearing grease;
  • Rags or unnecessary cloth to remove dirt.


Thru-axle (from the English. Through the axle). have high rigidity and are used in bicycles for aggressive riding. For the rear wheel, they are produced in widths 135, 142, 150 and 157 mm and a diameter of 12 mm. The width of the sleeve itself is adjusted with spacers on the side and 135 easily turns into 157mm without replacing the sleeve itself. For the front with a diameter of 15mm and 20mm and a width of 100mm and 110mm, respectively.

How to choose a bike here

Take full responsibility for the purchase and replacement of this part. Remember that a bicycle can bend or break down only because of its low quality. In addition, when choosing an axle, remember that they are made of different materials:

  • Titan,
  • Steel,
  • Aluminum.

Which, of course, determines their reliability. For mountain or road bicycles, there are some structural features.

DIY bike repair: rear hub

Of course, to care for your bike, you need to understand how it works. Of course, in the structure of the iron horse there is a lot that is complex and incomprehensible at first glance, but they do not lead to close their eyes to this. You need to look at the bike from different angles. Today we will NOT talk about the whole bike in general, but we will focus on what is in the area of ​​the rear wheel of the bike, in particular, on the axle.

The rear wheel is stationary and is located in a special movable hub of the same wheel. It is these bushings that provide the movement of the wheel, and they do this due to the fixed axle. In order to better understand where the back one is, we note that it is next to it that the needles are already attached. If something happens to the cones, bushings or the rear axle, you will have to disassemble and repair the entire rear wheel mechanism. Therefore, it is extremely important to ensure that everything connected to the rear axle remains intact and safe.

Standards: Kinds of quick-release axles for MTB wheels

The bushings on the eccentric allow you to quickly remove the wheels and NOT to steam up with the necessary tools at hand. And if you think that eccentrics are flimsy and not worth your attention, then today we will dissuade you!

Front behold Thru-axle

This eccentric is inserted into the closed dropouts, which prevents the wheel from falling in while the eccentric is closed. Although use on a frame with split dropouts is not recommended, unlike a fork you will be able to physically mount such a wheel to the frame.