How to disassemble the bushing
Sometimes it is necessary to carry out maintenance. Usually, beginners have difficulties in assembling and disassembling due to lack of relevant experience. But in reality, coping with this task is not so difficult with the knowledge, instructions and tools.
Be extremely careful when performing maintenance. It is better to lay out all the details on a trim of light fabric, so as not to accidentally lose an important component.
Disassembly always starts on the left side. Naturally, this process depends on the type of part used in your bike. We will analyze the procedure using the example of bulk bushings, which are used in most bikes:
- First, you need to unscrew the nuts and dismantle the wheel.
- The stars must now be removed to gain full access to the hub. Cassette wheels will require a whip and a puller for dismantling. If your bike uses disc brakes, you need to remove the disc.
- When using a ratchet hub, removing the wheel will require a puller and a wrench that can exert significant pressure. It is necessary to make every effort to unscrew, as the ratchet constantly twists when riding a bike.
- Next, you need two keys. A cone wrench is used to hold the cone, the second allows you to unlock the left nut to unscrew it later.
- Now pull the rear axle out of the hub to gain access to the internals.
- Metal dust boots are often used to protect the ball bearings from dirt. They must be dismantled and the balls removed. It is better to put these parts in a small jar so as not to accidentally lose the bearings.
When disassembling bushings with industrial bearings, problems arise when removing the cassette. They are well pressed, so they can be pulled out with a specialized tool. If it is absent, you can try to hit with a hammer along the axis in order to later remove the cassette
But you need to apply blows carefully, as there is a high probability of accidentally damaging the flange.
A special puller is required to disassemble the drum. You cannot do without this tool when dismantling this element. But the need to disassemble the drum appears very rarely, it is better to visit the service and entrust the procedure to professionals.
- Removing grease residues.
- Thorough cleaning of all parts.
- Applying new grease.
After servicing, the assembly is carried out in the reverse order. If all the parts are in stock, the components have not been lost, then this procedure will not cause difficulties for the cyclist.
Typically, the wheel hub acts as a housing. It is equipped with flanges for fastening the spokes. Due to the presence of stars on the rear wheel, the spokes on one of the sides get a slightly reduced length.
If this problem occurs, the flare nuts are overtightened. You need to repeat the steps described above, but now weaken these elements a little. In the absence of timely maintenance, gradual destruction of the bushing is possible.
Bicycle front wheel design
Before proceeding directly to the removal and disassembly of the front wheel of the bike, which is responsible for the trajectory of the bike, you should know what parts the structure consists of. The wheel is perhaps the main element of the bike, which has undergone some modifications least of all. Naturally, today you can buy bicycles equipped with alloy wheels, all-round wheels (for driving on a track). However, in general, regular bikes, speed bikes, or other models have traditional spoked wheels.
The front wheel is structurally simpler than the rear one and consists of the following parts:
- knitting needles;
- flipper. a rubber band (gasket) on the inner side of the rim, which protects the chamber from being punctured by the needles;
- tire and tube;
- disc if the bike is equipped with disc brakes.
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Having dealt with the device, we proceed to the next stage.
Rear axle. threaded rod. Its main task is to take on the load during operation is great. Alloys of steel, aluminum and titanium are used for its production.
The axles can be hollow or solid. The first type is used with eccentric couplers. This solution makes it easier to install and remove the rear wheel. Such parts have a low weight, and their strength is quite high.
Additionally, the wheel can be secured in the feathers with nuts. Axles with nuts provide a more secure fit, so they are widely available on the market.
Thru-axles are threaded at one end. Similar parts are used on some mountain bikes, they are part of the frame and are provided with the bikes in the kit.
When determining the thickness of the rear axle, it is necessary to consider the clearance between the dropouts and the type is large. Separate bushings support the change in diameter, for this special adapters are used. In the image below, you can examine the diameter and length of the axles for different bikes.
Backlash is caused by poorly tightened locknuts. During the ride, there is a characteristic beat of the rear axle against the bearings. If the backlash is not removed in a timely manner, then serious damage to the bushing is possible.
How to get rid of backlash? You need to gradually tighten the flare nut. Using the test method, find a position at which there are no extraneous sounds when the wheel is rotating. Now it remains to fix the cone with a lock nut.
Varieties and main constituent elements
Hubs are divided into two types. front and rear. The front ones are used exclusively for fixing the wheel. They act as a kind of attachment and axis of rotation of this element.
The rear hub of a bicycle is used not only to secure the wheel, but also to transmit power from the pedals. Therefore, it has high mechanical loads, it is on it that the parameters largely depend.
Bicycle rear hubs differ in materials used for manufacture, design and some other parameters. Several varieties of these parts are now on sale:
- Planetary. They use an internal gear selector and the main elements are located inside the housing. These parts are very reliable and do not require regular maintenance. Their only drawback is their high cost.
- Ratchet. They use a set of sprockets that are connected by a ratchet mechanism. Today these are the simplest and cheapest parts, they are installed in inexpensive bikes.
- Cassette. In these, the rear sprockets are placed in the drum.
The last two options are considered the most common on the market. This fact is due to their cost. Parts of the planetary type are much less common on the market. They are reliable, but cost a lot and can only be seen in some city bikes.
Rear wheel ratchet bushings are the cheapest and most widely available on the market. But it is better to choose cassette parts. They are more expensive, but much more reliable than models with a ratchet.
Common problems and how to fix them
Deformation or damage to the axle is caused by poor quality materials or design features of the bushing. This component cannot be restored, it can only be replaced with a similar one.
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.
The bushings, in addition to the function of holding the wheels, are responsible for the brakes. They are divided exclusively into V-brakes and disc brakes. It is very rare to find (on certain models of city bikes) drum brakes.
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.
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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).
Rear hub: general information
Everyone knows that the roll is better if the lever is larger, and the rear hub with the wheel just forms it.
And the better the sliding and rolling in the rear hub, the easier the wheel spins, giving a roll. It is believed that some of the pedaling power (energy) in the hub is lost, but science has proven that this is not true.
In reality, the losses are equal to 0.47%, so they can simply be ignored. Such insignificant losses are explained by the fact that the balls in the lubricant rotate around their own axis and the wheel, so it is not advisable to save on it.
There is no need to be afraid that the new rear hub is spinning slightly worse than the one that was in operation. This is a temporary phenomenon. The sleeve needs time to run in. If you need to replace it, do not skimp and buy a quality part.
But, among the available variety, which sleeve to choose for repairing the rear wheel of a bicycle: on industrial bearings, tapered, i.e. with bulk bearings, ball bearings?
The best acquisition will be a new development. industrial bearings, convenient in that they do not need adjustment and are reliably protected from negative environmental influences.
However, they are more difficult to install, so repairing the rear wheel of a bicycle with your own hands in field conditions is out of the question. Bulk, change in a couple of minutes, but need careful adjustment.
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.
Rear hub selection
There are several important considerations when choosing a rear hub:
Notice how the rear sprockets are attached. If your bike has 6-7 sprockets behind, as a rule, they are threaded, which means that we should choose hubs with a threaded mount. Typically found on entry-level bicycles, but there are exceptions. If you have 8-11 stars. such stars are attached to a spline drum. on Shimano hubs this is HG standard. it is more reliable and modern. We also take into account the number of stars. Not all splined drum hubs are designed for a 10 or 11 star cassette. Some bushings have drums for 9 or 10 stars, respectively, to install the cassette for 11. you need another bushing.
The difference between bicycle hubs
Let’s try together to find out what are the main features to consider when choosing bicycle hubs.
Important features and differences of bicycle hubs
Before you make your choice. several parameters need to be clarified, which do not depend on whether it is a front or rear hub.
Whether it’s a road bike or cross-country bike, any manufacturer will offer you many options. The difference will be in the basic design and the tasks that the bushing must handle.
Bushings for MTB or gravel bicycles must be more durable, withstand shock and constant vibration, while road bike hubs must have minimum rolling resistance.
Another hub options are those for regular city bikes. They can be planetary. with internal speed system, or single speed. and of course with or without a pedal brake. At the manufacturer Shimano for road bikes in the budget segment, the series 105. Value for money with excellent roll-off. While for XC bikes, the same manufacturer in the series Deore. bushings of this series will serve for a rather long time, and their maintenance will not be so expensive, because you can choose all the necessary spare parts in our section “Bushings and components
This parameter is very important for us, especially if we already have a rim. Also recently, bushings for straight spokes began to appear on the bicycle parts market more and more often. for such bushings it will be necessary to select special knitting needles.
It is very important to correctly calculate the length of the needles. Calculate according to your rim and bushing dimensions. For the calculation, it is best to use a knitting needle calculator, for example this one: Sapim Calculator
Mount type and axle diameter.
Compare with the old hub or check your frame and fork specifications. The correct axle diameter is very important. Different frames and forks have different mountings. it can be bolts, nuts, quick fastening with an eccentric or an axle. Entry-level kids, teens, city or mountain bikes usually have eccentric mounts or nuts. Top-end bicycles usually use eccentric or axle mounts. This type of fastening is much more reliable and increases the rigidity of the structure. Planetary hubs and single speed hubs generally have a 10 mm axle diameter. Another important factor of platerate hubs is the need for special mounting components for different types of bike dropouts.
Consider this parameter as well. While for rim brakes the sleeve does not require additional fasteners. bushings under disc brakes must have a special mount. Well, do not forget, even in road bicycles, rear hubs with a foot brake are often used. You should also take into account the fact that the rotor mounts are of two types: 6-bolt rotor bushings Center Lock rotor hubs
Depending on the type of bearing, the bushings will have different properties. Industrial bearing bushings. are stronger, more durable and do not require frequent maintenance, but the price of such bushings is much higher. Ball bearing hubs are more suitable for road bikes. These bushings withstand lateral loads better and have lower rolling resistance.
Relatively resistant to moisture and dirt. it has always been believed that bushings on industrial bearings are more protected. However, Shimano has developed their own system of protection against dirt and moisture, as a result of which, this allowed them to manufacture all hubs on balls, significantly reduce their rolling resistance, however, this does not affect their durability. We received reliable bushings with excellent performance. With the minuses, only the need for periodic service can be noted. although this cannot be called a disadvantage, because any mechanism needs to be serviced for excellent work.
Sleeve width. also an important parameter.
It will be very disappointing if, after long agony of choosing, the hub simply does not fit into the frame or fork feathers. Therefore, we recommend that you familiarize yourself with the documentation of the bicycle manufacturer before choosing a hub, or take control measurements of the old hub. Front hubs are typically 100, 108 or 110mm wide. The rear hubs have slightly more widths, usually 135, 142, 148 and 150mm wide boost hubs. It’s not so much even about marketing, but about the technologies that are developing. Older bikes have 135mm hubs, while modern ones use 142 or 148mm hubs. And on bicycles such as downhill or enduro, you can often find bushings with a boost of up to 150 mm. this improves wheel stiffness, which is certainly an important criterion for these bikes. Planetary hubs and single speed hubs have their own dimensions, usually 185mm.
Shimano 12-Star Hubs & Cassettes
Cassette bushings for 12 stars have their own difference. These bushings have a special Micro Spline drum that has a special tooth profile. The specialties of such a drum are:
- Specially developed drum hook technology
- The diameter of the drum was reduced, which made it possible to reduce the minimum cassette star from 11 to 10T
- Reduced free travel to the hitch
- Reducing noise when the drum is spinning freely
- Improved drum spline profile for increased traction and longer drum life compared to HG drums
The first series to use such drums was the XTR series. At the moment, several series already have 12-speed transmissions in their arsenal, namely: XTR M9100 DEORE XT M8100 SLX M7100 DEORE M6100 and hence matching hubs with drums with Mirco Spline technology
Also, the Shimano brand has in its catalog several more hubs with a Mirco Spline drum. series MT400 and MT500 Here it is important to say that they were made in order to be able to install 12-speed transmissions on budget bicycles with an eccentric mount with a width of 135 and 141 mm dropouts. And although the drum itself has slots for 12-speed cassettes, the internal grafting design uses the HG-standard, which does not make them less reliable, but more affordable in price.
Having determined all these parameters, you can safely start choosing a new part for your favorite bike.
We hope this article was helpful to you.
Go to bushing catalog Front hubs here Rear hubs here
Maintenance and replacement of carriage bearings
Periodic cleaning, lubrication and replacement of worn parts will help prevent sudden movement problems on your bike. Signs of a faulty carriage condition:
- “Clamps” in the pedals. difficult rotation or cranking;
- connecting rods dangle;
To remove the connecting rods and carriage cups, you will need special tools. pullers and an internal hex wrench. The dismantling process is as follows: 1. Turn over and fix the bike.
Unscrew the retaining nuts with a hollow wrench. You can also use a hammer with a chisel, however, the nuts must be knocked out carefully so as not to damage the connecting rods.
Using a puller, twist them off the axis. It takes a lot of effort here.
Pull the cups out of the glass with a carriage puller. The first is to unscrew the cup from the side opposite to the stars. Then remove the axle.
Remove bearings, inspect and replace damaged parts.
Clean in kerosene, refit and lubricate. When installing, carefully monitor the position: on the one hand, the bearing is placed with balls outward, on the other. inward.
After replacement, cleaning and lubrication, reassemble the carriage in reverse order. After tightening the connecting rods, check their rotation: the lack of effort and cranking indicates that you need to tighten the cups, and vice versa. In these cases, you will have to repeat the disassembly and adjustment.
Prom bearings are installed immediately, no adjustment required.
Disassembly and replacement of bearings on the front fork
The wear of the hinge assembly of the fork manifests itself in backlash, heavy steering and extraneous sounds from the speaker. It is not recommended to postpone the problem indefinitely, because the serviceability of the steering, along with the brakes, is a guarantee of safety.
How do I change the bearing for the fork? At first glance, getting close to him is not easy. The assembly is securely pressed and hidden in the head tube. However, in practice, everything looks simple:
- Turn the bike over and unscrew the front wheel.
- Put the bike in the normal position and pull out the stem with the stem (you need a wrench or hex for the inner nut).
- Unscrew the lock nut with an adjustable wrench and pull out the lock washer.
- Unscrew the cup.
- After dismantling the housing, carefully remove the bearing itself. The parts on the forks of most bicycles are not equipped with separators, so we make sure that the balls do not scatter.
- Inspect all components carefully. Be sure to replace rusty, knocked-out balls with new ones.
- Clean the glass, bearing and cup from dirt, and then lubricate thoroughly.
The installation of the fork is carried out in the opposite order: after pressing in the bearing, the glass is twisted, then the washer and the lock nut are thrown. Checking the tightness of the glass: when the bike is tilted, the front wheel should deviate from the straight position by 15. 20 degrees. If it practically does not move, it is necessary to loosen the hinge. A large deflection of the wheel indicates a weak tightening, and the glass needs to be tightened.
Replacing wheel hub bearings
The hub is not just a wheel pivot. Without the built-in articulation mechanism, forces would be transmitted unevenly to it, and the bike would not be able to move. The same symptoms appear when the bearings are worn out.
Disassembling the hub is as easy as disassembling a fork. For the rear wheel, the procedure will be slightly more complicated than for the front wheel, since you will first need to remove the cassette with sprockets. On a single-speed bike, the retaining ring and the sprocket itself are dismantled.
In general, the disassembly is as follows: 1. Remove the wheels from the dropouts.
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Dismantle the sprockets with a cassette puller and a locking whip. On single speed open the stopper with a screwdriver or a special spreader.
Unscrew the fastening nuts with a 15 wrench. For the rear wheel hub, unscrew the nut on the side opposite to the stars.
Pull out washers and bearing units. Bulk ones are being moved, industrial ones are being replaced by new ones.
Clean parts and replace damaged components.
Pull out the axles, wipe the inner cavities of the bushings.
Reassemble in reverse order. It is important to place the bearings correctly and press the cones in the same way as before disassembly. In no case should it be skewed, the details should exactly fall into their rightful places. It is not advisable to swap them during a bulkhead. This threatens with backlash and deterioration of the wheel travel.
New bearings are selected in advance according to the old ones. they must be the same as they were before the repair. Lubrication is the key to rebuilding and replacing (in the case of “bulk”). When installing the “flush”, the assembly itself does not need to be lubricated, only the inner cavities of the bushing and the axis. After installation, we check the performance of the wheels: smooth running without play and clamps indicates that the parts are installed correctly.
Varieties and replacement of bicycle bearings
Bearings are special parts for maintaining the performance and fixing rotating assemblies. Their scope applies to everything where there is rotation and mating. The bike did not stand aside, because, in fact, it is a full-fledged transport with all its features.
Bicycle bearings are installed in all parts of the bike that rotate, change position and are under load. They can be found in the drive mechanism. carriage, wheel hubs, steering column and more complex devices. ratchets, switches, rear shock absorbers.
Types of bicycle bearings
According to the type of construction, parts are divided into two types: rolling and sliding.
Rolling bearings are two mating parts with grooves, into which the rolling elements. balls. are inserted. Their even distribution helps to minimize friction in the assembly and, consequently, to extend the life of the entire bearing. The fixation of the position of the balls is provided by special partitions. separators. Simple parts without baffles will require more frequent adjustments.
They are used on a bicycle in moving units where high resistance to abrasion and pressure loads is required and slippage is not allowed. steering column, bushings, carriage. Can also be installed in complex mechanisms. shock absorber hinges and switch rollers.
Plain bearings are ballless parts. They are two elements that rotate tangentially relative to each other. Materials for manufacturing. bronze, steel alloys, metal plastics and everything that has a low coefficient of friction.
Compared to rolling bearings, they are less resistant to abrasion, since the two parts interact directly with each other. Wear causes a gap to appear, which causes backlash. Because of this, periodic replacement of the entire assembly or worn out components, as well as adjustment.
Rolling bearings on bicycles are divided into two types: cone-cup and industrial.
The first. bulk bearings. are open-type parts. They are represented by a cup in which balls are distributed along the groove, fixed with a cone nut. The body is pressed directly into the part itself. the steering column or the bottom bracket.
Prom bearings are closed parts, completely inserted into the movable unit. This is their fundamental difference from bulk. The system is protected from moisture and dirt penetration, resulting in a longer service life compared to cone-cup designs.
Advantages of loose-type rolling bearings:
- ease of removal and installation;
- can be adjusted in the field;
- it is permissible to change components separately.
Disadvantages include frequent adjustments and the need to clean up trapped dust and dirt.
Prom bearings do not require adjustment, lubrication or cleaning. The position of the balls, the amount of lubricant in the closed housing are kept constant. No water or abrasive gets inside the cartridge.
However, if the bearing is worn out, it will need to be replaced entirely. Far from civilization, it is problematic to do this. The price of “prom” is significantly higher compared to the cost of bulk.
Ceramic and ceramic-metal bearings should be noted separately. They are completely or partially made of ceramics, due to which their corrosion resistance is higher compared to their metal counterparts. In addition, they are better able to withstand temperature extremes. Parts of this type are installed on high-end bicycles.
So, the bicycle bearing, as we found out, is the most important part in every moving unit. Its good condition, timely maintenance and replacement will ensure good running characteristics and travel safety.
Bicycle hub device
The bicycle sleeve is the main part of a bicycle wheel. Its axle is clamped on the fork dropouts or frame. The spokes extend from it, connecting it to the wheel rim. Due to the bearings, the hub and the wheel rotate.
The device and dimensions of the rear bicycle hub
What detail is it impossible to imagine a bicycle without? It doesn’t matter if we are talking about a premium sports bike or the simplest budget bike, the answer is unambiguous, it’s a wheel. And without which the wheel will not spin? correct, without bushing. The better it is, the higher the speed of the bike, which directly affects its efficiency. Let’s take a closer look at how the bicycle sleeve is arranged.
Bicycle hub selection criteria
Today, the bicycle parts market offers us a huge selection of hubs. Let us dwell in more detail on each of the criteria for choosing a bushing.
Bushings are made from aluminum and steel. Aluminum are more expensive due to their light weight and corrosion resistance. Their reliability is also influenced by the manufacturing method: stamped and cast bushings with a flawlessly even surface are stronger than chiseled ones. At the same time, steel parts are more affordable, but prone to corrosion. In addition, they carry an impressive weight.
Shimano is rightfully considered the world leader in mid-range bicycle hubs. The main difference between the products of this company are thrust radial rolling bearings and the option of adjusting the bicycle sleeves during wear and maintainability, which is available thanks to them. The hallmark of Shimano bicycle hubs is the non-standard method of flangeless spokes. According to most cyclists, Deore LX has the best value for money in the range of this brand. A more budget option for those wishing to save money would be the Alivio. The rear hub on this model can be purchased for 15. e., and the front one. for 10 cu. e.
The bike hubs of the Taiwanese company Novatec also deserve attention of cyclists. As a newcomer to the bike parts market, this brand, meanwhile, is confidently gaining prestige due to its affordable price and decent product quality. This brand produces bicycle socks, various in terms of design and functionality. In the high-end segment, expensive sports bike hubs are made by companies such as Chris King, Hope, DT Swiss and Tune.