How to choose a bushing:
The first step is to decide where and how often you will cycle. It is important to pay attention to the weight of the giver, its resistance to stress and vibration, moisture and dust resistance. For example, a road bike hub should never be used when riding aggressively over rough terrain.
In the event that you do not plan to engage in serious cycling, but just want to ride around the city and in uncomplicated conditions, then you can rely solely on your financial capabilities. Because the higher the level of the bushing. the stronger and better it is, naturally.
You also need to know how many spoke holes are on the flanges. The most common choices are 36 and 32, but things can be different with some bikes, such as road bikes. And if the bushing has the wrong number of holes. it will not work to combine it with the rim.
Which bearing to choose, industrial or bulk, you decide on your own based on the driving conditions, we wrote about this above.
You also need to pay attention to the method of mounting the rear sprockets and their type, which can be slotted or threaded. Slots of cassettes from different manufacturers can be different in height and width, so it is sometimes impossible to combine them. If by any chance your hub has a wider drum than necessary, you can place spacers in the free space, so-called. “spacers”.
Among other things, pay attention to the type of brake rotor mounting. The most common of all are the threaded centerlock and with six bolts.
If financial capabilities allow and under certain driving conditions, planetary hubs are very good. They have no equal in terms of convenience and durability, but they are more expensive, of course.
How bicycle hubs work:
The most important thing in the life of bicycle bushings are rolling bearings. these are ball parts used to transfer torque from the axle to the body of the part and, as a result, rotate the wheels. Today there are three of the most common types of rolling bearings used in the bicycle industry: ball, industrial or closed, and cage.
The front hub device looks like this:
It should be noted that bushings of all types and varieties of bicycle horses are similar in structure. Naturally, the differences may lie in the material used in their production, the degree of protection, weight, safety factor, running resource and durability.
If we compare the front and rear hubs, then they are simpler in design, because less dynamic load falls on them, as well as on the entire front of the bike. The complexity of the rear mechanism comes down to the fact that there is the possibility of free wheeling, this does not apply to fix-bikes. This confirms the fact that the front bushings are less whimsical in the repair and periodic maintenance.
Now let’s take a closer look at different types of bushings and their special device. If we talk about the type of production, then they can be stamped, cast or point. Most modern bicycles are equipped with stamped and dotted ones. Dots are highlighted with a trace in the form of a spiral on the surface from the outside. As for cast, they are put on models for beginners, teenagers and models for children, because they are less durable and weigh more.
The following materials are used for the production of the bushing bodies: titanium and aluminum. for point and cast, steel. for stamped. In addition, there are bushings with bodies made of carbon. so the bike becomes much lighter, because the weight of the carbon hub (which, at the same time, is not inferior in strength to others) is 49 grams, while the aluminum ones weigh 245 grams.
The axles of the bushings are made mainly from aluminum and steel, sometimes also from titanium. Their diameter is possible different.
Let’s select the most common axis sizes:
The most common option in use.
Found on trail and cross country bikes, is hollow itself, has an eccentric clip.
Found on models for extreme sports, also hollow. Can be bolted. better withstand heavy loads. As for the eccentric clamp. put it on and off faster.
Found in almost all new models, very widely used size.
Used on models manufactured for extreme sports.
Choosing a Hub
The diameter of the axle of any bushing determines such characteristics of the connection as rigidity and strength: the larger it is. the more options can be provided. This affects the total weight at the same time. In addition, removing a wheel with such an axle requires a lot of time and effort.
The rear hubs are often asymmetrical to accommodate cassettes. For this reason, the right flange is closer to the middle and its spokes are shorter on the right side by a few millimeters. This fact must be taken into account when lacing the wheel.
Now let’s dwell on bearings. important part of the bushings. Now more often you can find bushings with bulk bearings, and with cage bearings. less often. Their distribution is due to their high running life and ease of production, and as they wear out, they are easy to adjust and sort out. A well-known manufacturer in the cycling industry like Shimano exclusively uses bicycle hubs that have loose bearings.
Bushings with industrial radial bearings are less common. Compared to standard ball bearing systems, they do not need to be disassembled and are very easy to install. Such bearings can greatly increase the running life of the part, have better dust and moisture protection due to higher efficiency and lower rolling resistance. However, this greatly affects the weight of the part, since the weight of closed systems is greater, as is the hub body for them. This type is found in those bicycles to a greater extent that are used in extreme sports.
Varieties of rear bushings and their differences
As mentioned above. the rear wheels are more complex axial than the front ones. In addition, the hubs have special inserts for the ratchet, cassette and brake discs. On those bike models that have planetary gear shifting, the rear hubs are gear systems that can be compared in complexity to a car gearbox. On today’s city bikes and USSR bikes (classic), the bushings in the back still have brakes.
The rear hub looks like this:
a hollow bolt securing the bushing drum to the body;
Types of rear bicycle sleeves by structure:
the classic version with a ratchet or cassette mount. Many models also have a brake disc mount, i.e. rotor;
fixed gear, no free play;
The planetary hub is a part that can generate a lot of interest among cyclists. Its body contains the entire multistage transmission, so it does not need frequent adjustments and adjustments, it has an excellent running life and 100% protection against bad weather conditions. A very important point: when there is a planetary hub. gears can be changed even while standing still, but along with these advantages, it is worth noting the larger size and weight of this part.
Worm-type bushings are used on bicycles at one speed. The main difference is that braking occurs when the pedals are retracted. Frequent maintenance is not required for these bushings. they have a sealed housing with an abundance of lubricant, so they are also quite durable.
Fans of fixed bikes are madly in love with bushings with no free play, which provide continuous pedaling while in motion.
Two-star or flip-flop hubs are such a system that allows the wheel to rotate as much as 180 degrees. At both ends there are star mounts, where 2 stars with different diameters can be placed. The required sprocket size is based on the anticipated possible driving conditions. In addition, such bushings can simultaneously have both fixed and freewheeling options. “bicycle horse” can act as both single-speed and fixed gear.
Another exotic variety. shock absorber bushing. It weighs a lot, its design is complex and it is simply impractical to use it everywhere, since it has a very mediocre performance of its direct depreciation functions. Such depreciation is carried out here as follows: the bushing moves along the guide bracket on the axis, in the free space at it. an elastic element that absorbs vibrations, being both a spring and a damper. There are no strong shock-absorbing abilities, therefore such bushings are little known.
There are differences between the bushings and the type of rear sprocket attachment. There are threaded and spline types. The first of bicycle production is gradually leaving, since there are many disadvantages of the threaded connection of the sleeve: during installation it is easy to break the thread, low rigidity and strength, uneven wear of the mechanism and the stars themselves, a lot of energy losses in the unit. The installation of such rear sprockets is carried out due to the cheapness and ease of production.
As for the spline connection, there are many advantages: less weight, greater rigidity due to the greater distance between the bearings, less energy loss. more wheel rolling, good fastening reliability, with proper use, it is almost impossible to tear off the cassette from the slots, you can change not the entire cassette, but its individual stars if necessary.
Bicycle hubs: varieties, selection and care
What is the most important part of a bike? It’s a wheel, of course. It doesn’t matter what type of bike we are talking about, in what price range it is. none of them without wheels is simply impossible to imagine. And what is directly responsible for the rotation of the wheels? Quite right, these are the bushings. The better they will be. the better the bike will be “rolling”, which in turn affects its efficiency. Also, the bushings are responsible for the correct and even distribution of radial and circular loads, even rotation of the wheel, sometimes. stopping the bike or switching speeds. Since this element is obviously important. let’s talk about it in more detail.
The correct operation of the bushing requires periodic maintenance. It is important to carry out such manipulations as:
replacement of cage bearings or bearing balls;
on the brake sleeve you need to adjust the pads;
lubrication from the inside of all parts, and every 500 km. complete grease change.
If such necessary measures are not taken. repair or even replacement of the bushing may be required. Symptoms confirming the need for replacement or repair are considered to be: loosening and rumbling of the bushing, wheel play when driving, the presence of extraneous sounds during rotation, crunching of worn bearings, friction in bearings and poor roll-forward.
A loose, rattling or loose bushing can be corrected by pulling up using special keys. But here it is important not to overtighten, otherwise the wheel will begin to rotate poorly, which will lead to damage to the bearings.
Bad rolling and extraneous sounds can be corrected by good lubrication or by replacing the bearings.
I would also like to advise you not to engage in self-repair without the necessary knowledge, experience and tools. Professional bicycle service workers can do everything efficiently and quickly, identifying the exact cause.
We will be happy to answer the remaining questions and help with the choice!
First of all, the hubs are divided into front and rear. The front in its device is somewhat simpler, because it is responsible only for the fastening of the wheel and its rotation. The rear hub, in addition to these functions, also carries a ratchet or cassette. details here.
Ratchet and Cassette. A set of sprockets needed to shift gears. In the first case, they represent between themselves a monolithic non-separable structure, as a rule, of 5-7 stars. In the second case, individual stars can be replaced if necessary. For example, when a more running sprocket wears itself out. Cassettes usually consist of 8-12 stars. The cassette is the preferred purchase option. A cassette hub will always be more reliable than a ratchet and withstand more rider weight.
Separately, we note the planetary rear hubs. Their insides contain a gearshift mechanism (3-5). You can even switch while standing still.
In bushings with loose bearings, it is possible to adjust them by tightening / loosening the outer cups. They also better withstand angular loads that occur when the wheel tilts when cornering.
However, bulk bearings require frequent inspection and maintenance. If sand or other abrasive gets inside, then it begins to intensively wear out the balls and cups. And if the balls themselves and the outer cups can be replaced, then the inner bearing cups, which are machined inside the bushing, cannot be replaced. In case of severe damage, it is necessary to change the bushing or try to polish the cups, but this does not always help, and not every master knows how to do this.
- And one more detail: some manufacturers use a design with separators, while some just pour balls between the cups.
Bulk bearings. Requires frequent inspection and maintenance
Types of bearings in the sleeve and which is better
In modern bushings, 2 types of bearings are used: bulk and cartridge (popularly called prom, flushing, bushing on slips).
Bicycle hubs: what a beginner needs to know for DIY repair
In order not to collect bearings throughout the apartment, so that you do not have extra spokes, read what you need to know about bicycle hubs.
The hub is the central part of the wheel, resting on the fixed axle, which in turn is attached to the dropouts of the fork and bike frame. A high-quality hub is designed to provide minimal friction during wheel rotation, thus improving the roll of the bike. In addition, the better the hub, the longer its life and the fewer problems that arise after using the bike in wet weather and swamp. Bicycle hubs have a number of distinctive characteristics, in the twists and turns of which we will deal with.
There are different bushing axle standards. They differ in diameter: the larger it is, the more reliable the bushing, but at the same time it will also weigh more. For a regular mountain and cross-country bike, a diameter of 9-10 mm is characteristic, a more extreme. 14-15 mm.
The hub axles differ in length. The front ones are usually 108-110 mm, and the rear ones are longer. 135-146 mm.
In addition to fixing the wheels, the bushings are also responsible for the brakes. Thus, the hubs are divided into those that work only with V-brakes, and which are also designed for disc brakes. It should be understood that any bushing will fit the V-brake. There are also bushings for drum brakes, but these are rare nowadays and are found only on rare city bikes.
Number of spokes
The two most common standards are 32-spoke and 36-spoke hubs. Of course, the fewer the spokes, the lighter the wheel, but less durable, and vice versa. It is important that both the hub and the wheel rim are sized for the same number of spokes.
The hub and rim of the wheel must be designed for the same number of spokes
Rear hubs are sized according to the diameter and length of the rear axle (measured in millimeters). This measurement varies by frame design, so be sure to find out what size rear hub your bike requires. Mountain bike sizes available: 165×12, 157×12, 150×12, 142×12, 135×10 and 135x5mm
How to choose a mountain bike rear hub
Mountain bike rear hubs are the only part where constant noise isn’t a problem. What you hear is the sound of the ratchet pawls clicking on the bushing engagement points. Modern mountain bikes use rear hubs equipped with a freewheel that has a cassette mounted on it. The wheel itself rotates on bearings in the bushing around the axis. Rear hubs are available in a variety of sizes, designs and colors to excel in any mountain bike application.
There are three types of mountain bike rear hubs. single-speed, overtaking and with internal gearing. Single speed rear hubs are designed to accommodate only one gear. This can be done using a driver or a modified freewheel. Standard mountain bike hubs have a freewheel design that has a ratchet attached to the drive side of the hub to which the cassette is attached. Internal gear rear hubs, although rare, are also an option. This design does not require a switch, instead it uses a system of springs and gears located inside the hub to provide variable resistance.
Confused With Sizes & Standards? | Mountain Bike Wheels Explained
The rear hubs and freewheel housings are made of aluminum because they are lightweight and stiff. Some hubs use a carbon fiber mid section to save weight. Axles are available in steel, aluminum or titanium. Bearings are available in steel or ceramic.
Before making a purchase, make sure you know what axle size your frame is and if you require an internal gear model. Once this is determined, there are several criteria that can help you select the best model for you: intended use, bearing type, and rotor compatibility.
The overall design of a hub depends on the type of skiing for which it is intended. Downhill and Freeride Centers are designed to counter the abusive nature of their disciplines. All-terrain hubs have gotten rid of unnecessary material and weight due to more docile application. All-mountain rear bushings sit somewhere in the middle, balancing strength and lightness in their designs, and using a variety of bearing qualities and types. Some manufacturers opt for loose-sealed bearings, others prefer sealed designs.
Finally, there are two types of disc brake rotor standards, Centerlock and International Standard (six bolts), each requiring a special hub design. Be sure to select the model that is compatible with your brake rotor.
Buy and choose bike hubs
The hub is the central part of the wheel that allows it to rotate on bearings around a fixed axle that attaches to the frame or fork dropouts. A good model should provide as little friction as possible in the bearings while the wheel is spinning, thus improving the roll-forward is great. A high-quality model has a longer service life, fewer problems arise with it after driving in bad road and weather conditions, that is, it has greater protection against environmental influences.
Various modifications differ in several parameters, according to which they are actually selected. We will deal with these parameters in this article. We will also give recommendations where it is better to buy bicycle parts.
The different models are primarily divided into front and rear. The front one has a simpler device, because it is only responsible for fastening and rotating the wheel. The rear, in addition to fixing and rotating the rear wheel, serves as a support for the cassette or ratchet.
Both a cassette and a ratchet are a set of rear sprockets that the chain jumps over when shifting gears. The ratchet is characterized by a non-separable monolithic construction, usually consisting of 5-7 stars. The cassette is a more reliable design in which the stars can change in case of wear. Most often, only one, the most popular star changes. The cassette stars are usually larger than the ratchet. from 8 to 11. Cassette-type hub, always better and more reliable than a ratchet, it lasts longer and withstands a greater weight of the cyclist, although it costs more, and the cassette itself is more expensive than a ratchet.
Despite the cost, in most cases we recommend choosing bikes with a cassette rather than a ratchet, it is much more reliable. The latter option can be recommended only in the case of a very limited budget, and only for those who ride once a week in a walking style.
Ratchets are the lowest class of Shimano Tourney drivetrains, and any cassette. this is already a higher class, even the Altus is much better than the Tourney, not to mention the middle and high class. Therefore, replacing the ratchet with an upgrade cassette is great. it’s a good idea, but you will also have to change the hub.
Separately, we note the rear planetary models, such as Shimano Nexus, Alfine or Sram i-Motion. Inside such a mechanism are gears that provide gear shifting. Since the shift mechanism is protected from external influences by the housing, it is not afraid of bad weather and the road, therefore it lasts longer and does not require maintenance. The advantages also include the ability to change gears while standing still, while in standard transmissions, gears can only be changed while driving. This is useful for city conditions when you need to stop frequently at traffic lights.
The choice of a specific model is also influenced by the type of brakes installed. Some only work with rim brakes of the V-brake type, others are designed for disc brakes, but they also work with rim brakes.
There are special rear modifications, with drum brakes built inside, which are triggered when pedaling backward. Nowadays, this is a rarity, they are found mainly in children’s bikes, sometimes in budget urban.
There are two ways to fix the wheel to the bike. The cheapest and easiest option, which today is used only in budget bikes, is the classic one, with two turnkey nuts. A more expensive and convenient option. fastening with an eccentric. In this case, the wheel is removed very quickly, you just need to squeeze the eccentric handle. A very handy thing that is very appropriate when repairing a wheel, as well as when storing and transporting a bike. All modern high-quality bikes are necessarily equipped with eccentric wheels.
Bushings are available in aluminum, steel and chrome-molybdenum steel. Aluminum is lighter, does not rust, but at the same time is more expensive than conventional steel, which is heavier and corrosive. Of the positive qualities of steel, we note its great strength.
High-quality steel alloyed with chrome and molybdenum, which has undergone heat treatment, is very durable, therefore it is appreciated among extreme cyclists who perform breathtaking jumps and tricks or drive off-road. Hubs with a chrome-molybdenum axle and a drum are a great option for a BMX or MTB bike, of course, they cost a lot. These high quality bushings are often housed in aluminum, which reduces their weight.
The diameter and length of the axles also differ from model to model. The larger the diameter, the higher the reliability, but at the same time the weight increases. For an ordinary mountain or hybrid bike of an initial. average amateur level, the diameter of the axles is 9-10 mm, for a high-class, more extreme bike, the diameter of the axles increases to 14-15 mm. Sometimes an axle with a diameter of 15 mm is put in front, and 12 mm in the back. In some models, the axle diameter can be changed using adapters.
The length of the front models is usually 108-110 mm, and the rear models are 135-146 mm.
Today there are 2 common standards for the number of spokes on a wheel. 32 and 36. It is important that the wheel rim and hub are dimensioned for the same number of spokes. The more spokes, the stronger the wheel, but also the heavier.
The frictional force during wheel rotation, the need for maintenance and the service life largely depend on the type and quality of the bearings used. Quality models are usually assembled on non-separable industrial bearings. budget models usually have open bulk bearings that need to be serviced and adjusted. But, there are also expensive bulk models.
Having bought a good expensive bushing once, you can forget about replacing this spare part for 10 thousand km. mileage.
There are a large number of good bushings on sale, for example, here are some of them.
Quality rear cassette hubs for mountain or hybrid bikes:
- AUTHOR ACO-H04D-R / 36, price about 5000 rubles. Designed for 36 spokes and 8-10 speed cassette.
- SHIMANO DEORE EFHM525AAZL, price about 2500 rubles. Designed for 36 spokes and 8-9 speed cassette.
- AUTHOR ACO-H04D-F / 36 Blk, cost about 3600 rubles. Designed for 36 spokes.
- SHIMANO ALIVIO AHBM475AL, price about 2000 rubles. Designed for 36 spokes.
An example of a rear model for MTB bikes: COLONY Clone Freecoaster Hub Male, price 12,200 rubles. Equipped with a street-tailored fricoster. The housing is milled, a high quality angular contact bearing (ACB) is installed inside the driver.
There are rear and front modifications suitable for mountain, hybrid, road, city, road, folding, teenage, kids and MTB bikes. Both higher quality cassette and more budget ratchet options are presented.