Varieties of rear bicycle hubs, how they differ from each other
One of the reasons for dividing the rear hubs into varieties is their design. Depending on it, the rear bushings are divided into:
- Without brake.
- With built-in brakes.
It should be said that bushings that are not equipped with a braking mechanism are also divided into those without free play and with free play. With an integrated foot brake, the hubs are designed with free play. If we are talking about a hub with a brake mechanism, then their main feature is that you need to push the pedals in the opposite direction to stop the bike.
- Aluminum (lightweight and non-corrosive).
- Steel (strong but heavy and highly corrosive).
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The bushings also differ in the size of the axis, the standards are different. from 9mm to 15mm. Note that the larger the sleeve, the heavier it is.
The hub is located in the center of the wheels and is attached to the bike frame. Provides wheel rotation, eliminating slippage and turning. Rear hub helps roll the bike. efficient travel without wasting energy.
Bicycle rear hub design provides the following configurations:
- the presence of a free wheeling, lack of a braking mechanism;
- lack of free play, the presence of a brake mechanism;
- the presence of a free wheeling and braking mechanism.
The dimensions of the hub, its weight and quality affect the ride and energy consumption of the cyclist while riding. There are three types of this node.
- Ratchet Hub. Modern rear hub allows cassette sprockets to be mounted on the drum. The bearings are located closer to the middle, which negatively affects the uniformity of the load distribution. It is customary to complete teenage and inexpensive bicycle models with similar bushings.
- The cassette hub is another modern mechanism option. In this case, the cassette is fixed by means of the slots located on the sleeve. Such bushings are reliable and can withstand loads of up to 120 kg, since the bearings in them are located closer to the edge.
- The planetary hub of the rear wheel of a bicycle is a design that combines the functions of a hub and a derailleur. The device of the rear wheel hub of this type of bicycle is rather complicated: the mechanism is closed by a case, which protects it from dust and moisture. In this case, the chain when working with it will last longer, since it does not change the position for switching speed.
The 3-speed hub has a simple design, while the 5- or 7-speed gears are best left unassembled. Gears of planetary systems are installed in a certain position during assembly. Such work requires special equipment.
So, step by step
- The rim brake opens, if any
- We remove the damaged wheel, having previously unbuttoned and unscrewed the eccentric. Make sure that the unscrewed nut and the removed spring are not lost when falling
- We lower the pressure in the chamber to the minimum
- We stick a bead between the tire and the rim located on the side of the wheel. The side must be opposite to the nipple
- We release the border towards the center of the wheel and hook it onto the spoke, do not forget to do this, because this is a common mistake of novice cyclists
- After 5-10 centimeters, repeat, but with a different border
- Remove evenly, with both hands, finish near the nipple
- Removing the camera
- We remove the second bead of the tire. Do not forget to look and feel the tire, suddenly there is some sharp object or pebble that will ruin the next tire
Disassembly, cleaning / lubrication
How do I remove the rear wheel hub on my bike for 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 axis is removed;
- inside the case is cleaned with a soft cloth, all elements are lubricated (special attention must be paid to the bearings).
How to assemble a bicycle rear wheel hub? Assembling the rear wheel of a mountain bike or any other bike is carried out in the reverse order. When installing parts inside the case, you must first put grease on its walls.
Important! When tightening, it is necessary to avoid overtightening, otherwise it may jam and excessive wear of the structure during operation.
The rear wheel is then replaced. How to do this is shown in the video.
Before proceeding to disassemble the rear wheel of a bicycle to repair the hub, you must clearly understand the order of these actions. 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.
Spoke 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.
The main types of wheel spacing
There are two main types of knitting:
There are several more names that are a refinement of the pattern resulting from the spokes of the wheel:
- Twisted knitting needles.
The main difference between radial and cross or tangential spokes is that the radial spokes do not intersect with each other.
A rather vulnerable part of the structure. In addition to the rider’s weight, which is exerted on them, the spokes are regularly subjected to the 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.
Depending on the production process, the knitting needles can be:
- katan (the cheapest option);
- pulled (light, but more expensive);
- flat (the most expensive option, surpassing others in weight and resistance to oncoming air currents).
Types and arrangement of the rear / front hub of a mountain bike
In the MTB class, only two types of sleeve mechanisms are common: axle-cone-ball bearing and axle-industrial bearing. It is clear from the names of the classes that the difference between them lies in the structure of the supports.
The most common type. Particularly in the Shimano range, you will not see a knot on the “slip”. The company explains this by the fact that the design based on cone-nuts has better reel. The configuration elements of such a product are shown in the figure:
The procedure for assembling and adjusting the hub cones using the example of the rear wheel
All actions in the assembly process are performed in the reverse order of disassembly. So, the first row of anthers is immediately installed. In the example, there is only one such elastic band and is located on the side opposite to the cassette drum. In front of these elements there are two. one per side. If we are dealing with a rear bushing, then the dust protection on the locked cone must be installed even before it is lubricated according to paragraph 5 of the technological instructions.
Next, you need to carefully insert the axis. Remember to enter it from the side of the cassette. That is, the untouched cone nut should be on the side opposite to the position of the disc brake rotor. After inserting and tightening the cone nut and lock nut on the left side, proceed with the adjustment:
- Screw in the previously unlocked cone by hand until it stops.
- Loosen the tightening by turning the flare nut in the opposite direction. It is enough to unscrew it by about half a turn, and then make sure by staggering the axle in different directions if there is any backlash. If there are none, then it is necessary to loosen up again and check the beat again. The purpose of this stage is to catch a slight play, slightly perceptible with your fingers.
- Tighten the cone nut slightly. This can be any angle within 1/4 of a turn from the position found in the previous paragraph. Backlash must go away.
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- Lift the wheel and check its free play by twisting the structure by the spokes or drum. There is no specific criterion for assessing the smoothness of rotation: someone looks to see if the rim turns under the weight of a nipple or reflector, someone relies on experience, examining the nature of the free wheeling by eye. If the stroke is tight, the nut must be slightly loosened.
- When the wheel rotates freely, the cone can be countered. To do this, use a thin wrench to fix the flare nut, and tighten the lock nut tightly with a union tool.
- Make sure there are no backlashes.
At the end of the assembly process, a second row of anthers is put on and an eccentric is installed. At the same time, it is important to check the tightness of the seating of these sealing rubber bands. So, the situation depicted in the photo is not allowed. When replacing the cassette, align the thinnest spline with the smallest groove on the sprocket set. It is advisable to lubricate the end of the lock nut with the same grease that was used to treat the bearings. No whip needed during assembly.
After installing the wheel on the bike and fixing the eccentric, check that there is no play in various positions (rotate a small angle and check). A slight runout is allowed only in one of the investigated wheel positions. If the backlash is noticeable in any position, do not rush to repeat the procedure for adjusting the cones. tighten the eccentric. This helps to select a slight backlash.
How to apply lubricant
The goal is to lubricate balls, cones and cups. This can be done as quickly and efficiently as possible using the following technology:
- Lubricate the cup with your finger.
- Put the balls into the cup using medical tweezers, observing the intended purpose of the groups sorted during disassembly.
- Apply a thin layer of lubricant over the balls.
- Repeat steps 1-3 for the second side.
- Put the boot on the locked cone located on the side of the cassette (only relevant for the rear bushings).
- Apply a thin layer of grease to the beveled surface of both cone nuts.
There should not be a lot of lubricant at the contact points. This statement is relevant only because excess grease is squeezed out through the anthers, and it intensively begins to collect dust. You can estimate the sufficient filling level from the photo. There are usually no problems with the installation of balls. They adhere well to the lubricant, which is already in the cup according to paragraph 1 of the technological instructions.
It is customary to lightly coat the thread on the axle and the ends of the nuts with a compound that was used to treat rubbing surfaces. This activity is designed to minimize oxidation of metals and the formation of rust at the interface of detachable parts.
How to sort out the rear hub of a speed bike
The word “bulkhead” in its entirety is relevant only for tapered products. The maximum that can be done in the support on the “slip” is to clean and lubricate the bearings, and without removing them.
The repair principle for the front and rear cone nut bearings is the same, although the design differences are obvious. A set of sprockets is installed at the back; another design of the boot on the side of the cassette. However, the “backbone” is completely identical: that in the back, that in the front, on both sides, one cone-nut and one row of balls laid in bulk.
So, the subject of discussion is mountain bike rear cone service. It can be ratcheted, like on entry-class bikes like the Stels or Forward, or cassette like on mid to high-end bikes. By the way, in the material on how to choose a mountain bike. we have figured out in detail the differences between these two designs. There is also a recommendation on which design should be preferred.
How to disassemble
Initially, it is necessary to provide unhindered access to the flare nuts. For this, they usually remove:
- Disc brake rotor. Not in all cases can be dismantled. Make sure that the bolts do not interfere with the installation and rotation of the tapered (thin) wrench. If there is a gap between the key and the disc, it is not necessary to remove the latter. There are situations when the tool fits freely in the back, and on the front hub it is impossible to do without removing the rotor.
- Cassette / ratchet. It is imperative to remove, otherwise you cannot reach the second cone, and the axle cannot be removed. The process of dismantling the cassette is shown in the photo.
When the flare nuts are accessible, you can unlock one of them. In this case, it is important to observe two rules:
- Only one side is allowed to unlock! The second must be locked to failure even from the factory and it is forbidden to touch it.
- You can only unlock the cone located on the side of the rotor mounting (if there is no disc brake, then focus on the side opposite to the cassette). The fact is that the cone nut, weakened from the side of the sprockets, self-tightens upon impacts or collisions with an obstacle, which is why the free movement of the sleeve is disturbed. And this reduces the resource and worsens the roll-forward. This does not happen with the left side, since there the cone-nut tends to unscrew, and the lock nut and eccentric prevent this. In total, such a scheme maintains a balance and you can choose a gap without prejudice to the roll.
The deconstructing procedure is shown in the photographic material. A thin cone wrench adheres to the cone-nut, and with another wrench (for convenience, it is advisable to take a more massive tool) unscrew the locknut. After that, the threaded parts are completely twisted, and the axle is removed. Next, you need to remove the anthers and remove the balls from the cups.
Attention! When disassembling, note the order in which the components are located. The ideal option is to take a photo of the placement of anthers, nuts and washers on fresh tracks, as shown in the image.
When dismantling the balls from the seats, it is important to separate them into two groups. Those on the right must be folded in one place, those on the left in another. Do not mix or confuse these groups with each other, otherwise, after assembling the perfect reel without backlash, you will not get.
Important! When removing the axle on the front wheel of a bicycle
without disc brakes, mark the side of the non-rolled cone on the tire. Another landmark on this type of bike is the direction of rotation of the rubber shown on the side.
Industrial bearing bushing
Many people dislike bushings on flare nuts because of the difficulties associated with adjusting them after assembly. In this regard, the worn out support is often changed to the version with “slips”.
The advantages of the industrial bearing design include easy maintenance. There is no need to adjust anything here: the bearing fits snugly in the cup and on the axle, there are no flare nuts. In theory, such a wheel should not have any backlash, which is demonstrated by expensive specimens. In cheaper models, low-grade rolling bearings are used, in which the clearance is observed even from the packaging.
For your information. Backlash in the bushings due to “slip” is eliminated only by replacing the bearings. The latter are difficult to remove, therefore, when critical gaps appear, the mechanism is replaced as an assembly.
Eliminate scrolling on a bike
The work to fix the problem can be broken down into several steps.
The rear wheel must be removed first in order to be able to dismantle the transmission. The chain and the entire chain mechanism must be cleaned and lubricated. Especially carefully it is necessary to process the gaps between the rollers and the sprockets.
Then you need to replace the sprocket and the chain itself. You cannot limit yourself to one thing, because the mechanism works as an integral system: removing a minor malfunction does not mean that it has solved the problem.
The repair itself comes down, in fact, to finding and then replacing the damaged part. When the wheel is removed, it is necessary to sort out the bushing along the spokes, inspect each separately, check whether the roller is worn out and whether the cone axis is intact.
Do not grind the taper axle in a special workshop, even if you are assured that this will solve the problem. Wear is wear: the part must be replaced with a new one.
Scrolling on a road bike
To find out why the pedals on a road bike spin, you need to pay attention to the features of its structure. Road bikes and any foot-operated bicycles are particularly prone to bushing wear. Over time, its components stop clinging to each other, and the mechanism of operation goes wrong. The wheel rotates at idle, as the pedal scrolls the stars, not the wheels.
Reasons for the appearance of scrolls
Most likely, the scrolling on the bike was the result of the wear of one of the parts. It remains only to understand which one. The most vulnerable points of the pedal mechanism are:
- rear sprocket;
- rear wheel hub and parts thereof.
What to do if suspicion falls on one of the listed elements? As a rule, these details “hint” to us in advance that it is time to take care of them. An attentive cyclist anticipates a problem and does not lead to a complete breakdown. If the cranking nevertheless begins unexpectedly, a careful examination of not only the pedal, but also the entire driving mechanism will help to remove it. When examining your bike, you should pay special attention to:
- rear hub;
- front wheel sprockets;
- cassette or ratchet;
Scrolled on a racing bike
Cranking on a speed bike is often caused by a rear wheel defect found on many modern models. It can be more difficult to fix the working mechanism on a high-speed bike than on a simple bike, since the chains on the first are more whimsical than on the second, and require work with a large number of links.
Mountain bike pedaling
Mountain bike scrolling can also be caused by erasing complex hub parts or chain damage.
They are associated with driving over rough terrain at high speed. The risk of occurring deformations obliges the owners of such bikes to carefully inspect their vehicle every time after a bike ride.
How to remove scrolls on a bike
Sooner or later, every cyclist is faced with such a problem as scrolling the bicycle pedals. In a similar way, a failure occurs in the operation of the so-called crank-pedal group, which is responsible for the normal movement of the bike. To eliminate the malfunction, you need to determine which of the parts has become unusable.
Prevention of pedal scrolls
Keeping clean, as in the human world, helps a lot to maintain cycling “health”. Why does scrolling occur even after replacing worn parts? Due to lack of maintenance of the bike and its parts.
In order to clean the bike cassette, it must be removed. With a pre-prepared brush with flat bristles, you need to walk along all the links of the chain. Then. wipe all the teeth and washers with a napkin soaked in kerosene. (Never use gasoline: it can cause rust!)
And, of course, the main culprit of bicycle scrolling. the chain. requires special attention. There are several mandatory procedures for caring for her:
1. Flushing. It is advisable to rinse the chain and clean the links from adhering dirt after each ride, especially in autumn and spring. You can pre-stock kerosene, white spirit, or any other cleaning agent. Before applying the cleaner, the chain must be cleaned of dirt by thoroughly rinsing it in a separate container.
Lubrication. A clean chain must be thoroughly lubricated. You can use for this both liquid or thick lubricants in oilers, and aerosol products.
It is better to choose a more expensive and better quality lubricant. Ideal for, for example, a thick composition “Litol 24”, which does not allow water and bulky dirt spots to pass through.
With timely care of the chain and other parts of the driving bicycle mechanism, there is a chance that the pedals will begin to spin only after many years of use of each part.