When to remove the rear wheel
It is unlikely that the idea of unscrewing the chassis from the bicycle frame would just come to mind, unless, of course, a person specializes in bicycle dismantling. But this is a completely different case. Dismantling the rear wheel will be required if the following problems are observed:
- noticeable damage to the rim;
- complete wear when a wheel needs to be replaced;
- a flat tire or a burst tire;
- bulkhead bushing.
This includes the planned replacement of the rear sprocket system and chain.
Before removing the bike, turn it over and place it on the saddle and handlebars. It is better to remove awnings in the form of a mirror, a bell and a lantern in advance so as not to damage them under the weight of the frame. V-brakes are first released and disassembled, otherwise they will not allow the wheel to be pulled out freely. With disc models, everything is easier. you can immediately remove the wheel.
I must say that the removal process itself consists only in unscrewing the eccentric or unscrewing the fastening nuts from the axis of the bushing, who has something. If the mount is an eccentric, simply unscrew the handles and twist the wheel. The nut fastening is loosened with one or two wrenches.
Usually one wrench of the appropriate size is enough, with which the nuts are removed one by one. If the hub axle turns, then the nuts are unscrewed simultaneously in different directions. It is recommended to use open-end wrenches or box wrenches. The adjustable version is undesirable, as its thick horns “eat up” the corners of the nut due to loose fit and sliding.
When to Service the Rear Hub
To ensure that bike parts are always in perfect technical condition, they must be regularly serviced. If we consider the rear hub of a bicycle, then for it you will need:
- periodically tighten the body;
- regularly change the bearing balls;
- at the next disassembly, lubricate all internal parts of the case;
- adjust the brake hub from time to time.
Dismantling the rear wheel itself is as easy as shelling pears, but the process of removing and disassembling / assembling the rear bicycle hub is much more difficult. And nevertheless, without such regular maintenance of the part in question, it may soon need to be overhauled or replaced.
Signs that indicate an urgent need for service on the rear bicycle hub:
- when driving, there is a strong wheel play;
- the crunch of bearings is clearly audible (this means that they are simply worn out);
- on the go, the bike body rattles and staggers;
- rolling dynamics is bad.
It is worth knowing some of the features of eliminating a particular symptom:
- If the rear hub casing is spinning, its looseness, then this can be eliminated by tightening the fastening nuts.
- If the movement of the rear wheel is difficult, then it may be necessary to loosen the retaining nut a little. most likely, too much force was applied when tightening it.
- If extraneous sounds appear when the bike is moving and the roll-forward deteriorates, you will need to replace the bearings or completely lubricate the rear hub housing.
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 placement 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.
- 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.
What Is Inside A Bike Freewheel/How Does It Work?
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 properly disassemble, clean and lubricate the rear hub
Immediately remember one truth: any service is recommended to be carried out with a snagged sleeve. Otherwise, the chances of assembling the wheel correctly and quickly are unlikely to work. this can only be done by a person who is already experienced in servicing bicycles.
Step-by-step instructions for maintaining the rear bicycle hub:
- Remove the cassette from the axle using a whip and a puller.
- Opening the retaining ring.
- We remove all bearings and washers.
Note:the sleeve can be on industrial bearings and bulk bearings, but in any case, it is very important to remember their original location in the sleeve. This rule must be observed when removing the washers.
- We carry out a careful inspection of the bearings. if they are damaged, then this means the need to replace them with new parts.
- We take out the axle. it does not understand.
- We clean the body of the rear hub of the bicycle from dirt. All internal cavities must be wiped with a dry cloth.
- When installing back, each part is thoroughly lubricated, special attention should be paid to the bearings during this process.
- The last step is to install the stopper and tighten the fastening nut. It is not necessary to apply great efforts to tighten, as this can result in a problem of free wheel rotation.
Of course, everything looks quite easy and simple, but there are a lot of nuances in servicing the rear hub of a bicycle. they must be known and taken into account in the process of work:
- Firstly, the direct disassembly of the bushing should be started only after the cassette has been removed. over, the sleeve is disassembled from the opposite side and, as a rule, it is on the left. The locknut, if any, is unscrewed with a 15 mm wrench, then the stopper is removed (again, if any).
- Secondly, you need to be extremely careful when removing the washers and rings. they will need to be laid out on a pre-prepared sheet of paper in the exact order, if this moment is overlooked, the assembly of the rear bicycle hub after cleaning and lubricating it can turn into a real torment.
- Thirdly, after twisting the housing of the rear hub, its axis will begin to give in. just at this moment the bearings will appear. And again, you need to be extremely careful when removing the bearings. the parts are small and easy to lose. We remove each bearing with a knitting needle or tweezers, carefully wipe it with a rag soaked in kerosene or gasoline, and put it aside. Just in the process of wiping, the bearings must be carefully inspected for damage, and if there are any, then the part must be replaced.
Note: in the articles and instructions for servicing the rear hub of a bicycle, you can find a recommendation to use acetone to wipe bearings. this is permissible, but it should be borne in mind that the aroma from such a product will not be the most pleasant, and acetone can corrode the skin on the fingers. And one more thing. many “kulibins” in order not to lose small bearings use a magnet. in no case should this be done! The fact is that the bearing is magnetized and during the operation of the bicycle, iron dust is attracted to these small parts. the fact that the hub will soon become unusable can be predicted with confidence.
It is highly undesirable to confuse the left and right parts when disassembling / assembling the rear hub of a bicycle. this can lead to wheel play. If at least one ball is lost, then you will have to carry out a full replacement of the bearings. Sometimes, when opening the bushing near the axle, you can observe iron “dust”. this means that the bearings are completely worn out, they must be completely replaced.
Before you start disassembling and assembling the rear wheel of a high-speed bike, you need to find a comfortable place to stock up on gloves so as not to get your hands dirty. If there is no relevant experience, you should strictly follow the sequence of actions, take into account all the subtleties. A great help in this matter. training videos.
How to disassemble the rear wheel on a speed bike
We work with the inner space of the bushing
After the axle has been removed, you need to carefully inspect 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 (if heavily soiled) you can use gasoline. So, we wipe the left cone and examine the right one for fastening strength. Only after the axle walls are completely dry (if gasoline was used for processing), can new grease be applied 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. Bearings are often used for bearings. this lubricant will be the most suitable. Too thick a layer of grease should not be applied. during the operation of the bike, it will be squeezed out and actively absorb dirt, which leads to rapid wear of the part.
How to loop through the rear and front hubs on a speed bike
Bulkhead bushing, whether it be rear or front, is an event that can be either forced, due to water entering the bushing, or routine. Its purpose is for the most part preventive. to change the lubricant and, if necessary, replace some components. If we are talking about a conical bicycle classic, then it can be a worn ball or a cone. However, on high-speed bicycles, there is another type of support that also needs maintenance.
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:
Obviously, in order to repair a wheel, it must be removed from the bike. For this, it is better to put the latter on the handlebar and saddle, after removing the attachments. There are two ways to fix the wheel to the frame:
- an eccentric through the hollow axis;
- nuts or lambs.
In the first case, you just need to turn the eccentric lever 180 degrees and then unscrew the nut on the opposite side of the axle. In the case of an eccentric attachment, the axle of the rear
wheel of a bicycle on one side does not extend beyond the thickness of the fork in which it is installed. Experienced users must take this point into account when repairing. In the second case, the rear wheel hub axle is always longer than the distance between the fork stays by at least 15–20 mm. Thus, the axle extension beyond the outer side of the fork should be no less than 5-6 mm on each side. It is important to observe these ratios when re-assembling the rear wheel hub. After the fasteners are removed or loosened, the chain must be dropped from the drive sprocket and the wheel can be removed. If the bike is equipped not with disc brakes, but with rim brakes, then most likely you will need to dissolve them by throwing off the brake cable from the traction.
Cleaning and lubrication
It is necessary to clean the balls and cups in contact with them, cone-nuts, axle. In a sleeve with good dust protection, the lubricant is usually clean, so cleaning can be carried out without chemicals. with an ordinary clean rag. If dirt is present, use one of the degresers we have recommended for cleaning the chain in the material, how to clean old bicycle chain grease at home.
Removing the cassette and bulkhead bushing
A hub is one part of a bicycle wheel that requires periodic maintenance. On average, you need to look into it once every 2000 km of run, in terms of time it is 2-3 months of active driving. If the wheel is already creaking and there is a decrease in the efficiency of rotation, in other words, the great rides worse, then it’s time to remove it and inspect the hub.
The main problems with the bushing are backlash and insufficient lubrication of the bearings. Due to a violation of the fit or increased friction, the parts begin to wear out rapidly. If the wheel has not been serviced for a long time, the bearings may crumble altogether. To gain access to the bearings of the hub, you will need to temporarily get rid of the rear sprockets.
The rear speed device is removed using a puller and a so-called whip. Removing the cassette is a short-lived affair, but it will take a lot of effort to unscrew it from the wheel. In stages it looks like this:
- The stripper is inserted into the cassette nut.
- The whip holds the large star of the system so that it does not turn.
- With a wrench, the puller rotates, unscrewing the slotted nut.
- We remove the small stars that are installed on top, carefully fold them to the side along with the washers, and then remove the cassette itself.
How Do Bicycle Gears Actually WORK?
Before disassembling the hub, you should slightly loosen the spoke tension. This can be done using a round key with knock-out holes for different diameters of the knitting needles. You need to loosen a little, a quarter of a revolution is enough. If the sleeve needs to be replaced, then the spokes must be unscrewed enough to easily pull it out of the engagement.
A complete bushing replacement is required if both the axle and the bearings become unusable. However, often when the bushing is jammed, the axle is in normal condition, it is enough to change the bearings. Often, both will still serve faithfully if they are well lubricated. Proper lubrication will prevent parts from wear under dynamic loads.
The bulkhead of the axle part of the wheel is associated with cleaning the axle and bearing balls from dirt. The removed parts must be temporarily placed in a solvent, then allowed to dry, lubricated and reinstalled. Bearings in a skewed position must be adjusted by returning them to a straight position. However, during the backlash, the parts are already faulty, so replacement is the best option.
Replacing the camera
To remove the tube from the tire, you must completely deflate it. It is necessary to pry the latter with spoons for disassembling, inserting them at a distance of about 15 cm from one another. After that, you need to start to spread the spoons little by little, until the entire side of the tire is removed from the rim. It remains to remove the nipple and remove the camera.
Installing a new camera is carried out in the reverse order:
- You need to insert the nipple into the rim and tuck the entire tube into the tire around the circumference, avoiding twisting and wrinkling.
- Before beading the tire onto the rim, you can slightly inflate the tube so that it takes its shape and takes its place in the tire.
- After prying the tire, it is necessary to fill it with spoons into the rim, first in the area of the nipple and then along the circumference.
After making sure that the tire has taken its place on the rim, you can inflate the tube to working pressure. After that, it remains to deal with the installation of the rear wheel of the bike, and the repair can be considered complete.
The wheel consists of a hub, spokes, rim, tube and tire. Sometimes the tube and the tire are one piece, that is, a tubeless tire.
The hub is connected to the wheel rim using spokes, the number of which ranges from 12 to 48. Prestigious models of bicycles with a frame made of composite materials are often equipped with wheels, the spokes of which are made of carbon.
The size of a bicycle wheel is traditionally determined by the outer diameter of the tire in inches. from 14 to 29 (1 inch = 2.54 cm). Mountain bike is usually equipped with 26 “wheels, and hybrid or touring. 28”.
The rear wheels of sports bicycles do not contain spokes, so they consist of a solid disc. This design increases the rigidity of the wheel and reduces the resistance of the oncoming air at high speeds. The only drawback is the increased windage, which adds trouble for riders in a crosswind.
The simplest rims are single-walled. The rim profile resembles the letter “U”. After adding an additional bridge to the profile, a reinforced type of rim is obtained. double-walled. Such a rim is stronger, it is less afraid of obstacles and holes on the roads. The most powerful type of rim is three-walled, when another bridge is inserted inside.
In the manufacture of bicycle wheel rims, steel or aluminum alloys are used in most cases. Steel rims are cheaper, but heavier and more susceptible to corrosion. In recent years, more and more lightweight composite materials are used: carbon and plastic.
Varieties of rear bicycle hubs, how they differ from each other
The hub is located in the center of the wheel and rotates on bearings. Collapsible balls or factory-made universal sealed bearings are used as bearings. The bearing carries all the pressure of the bike while riding, so its quality must be high.
The hub is spoked to the wheel rim. Outdated Torpedo bushings contain a brake drum inside the structure, with the help of which the cyclist brakes by reverse pedaling.
The modern rear bicycle hub features a ratchet mechanism and a cassette star cassette slips over the drum. On the ratchet hub, the bearings are closer to the center, so the load is not evenly distributed. Hubs of this type are installed on teenage or budget adult bikes.
Cassette hub is another popular type of rear hub. It has slots on which a cassette with stars is fitted and is fixed with a cassette nut. These bushings are more reliable, the bearings are farther from the center of the hub, so the bike can support up to 120 kg.
The third type of rear hubs is a hub with a planetary gearshift system. It combines the functions of the hub and the gearshift mechanism of the bicycle.
The entire mechanism is located inside the hub and is protected from dust and moisture. The chain on a bicycle with such a hub lasts longer, since it does not change its position. The planetary hub has a high degree of reliability.
SRAM’s 3-speed planetary hub is very simple in design. But it is better not to disassemble the 5 and 7-speed ones. Planetary gears are installed in a special position. this requires a special tool.
Bicycle wheel spoke
A very vulnerable element. In addition to the weight of the cyclist, it is subject to impacts on uneven roads. The nipple is used to fix the spoke in the rim. The most common knitting needles are made from steel or aluminum.
The steel spokes must be chrome plated. Stainless steel spokes have proven themselves well. They are durable and resistant to corrosion.
The spoke consists of four parts:
The nipple must be of the same material as the spoke. Otherwise, due to electrochemical corrosion, it is difficult to tighten and replace the spoke. The spokes are tightened only with a spoke wrench, in no case with pliers or other tools at hand.
- Rolled knitting needle. budget option.
- The pulled spoke is lighter in weight but more expensive.
- Flat spoke. the most expensive, significantly superior to other types both in weight and in resistance to oncoming air flow.
Spoke is the order in which the hub, spokes, and rim are fastened together. There are two main types of wheel lacing: “radial” and “cross”.
In the “Radial” view, the spoke does not intersect with the others. When assembling “crosswise”, a knitting needle is crossed with the rest of the knitting needles several times, depending on the selected spoke method. On widespread 26-inch wheels, three-cross lacing is more commonly used.
Bicycle rear wheel device
Broken rear hub
The most common rear wheel hub failure is a loose cone or overtightening. Loosening of the taper leads to an increase in the wheel axle play. If the situation is the opposite, when the cone is overtightened, then the ease of movement of the bike disappears. In the worst case, a characteristic crunching sound can be heard in the bearings. Both situations are emergency, so you need to immediately start repairing the rear hub.
Eccentric locking rear hub.
Rear hub axle.
This requires removing the rear wheel. On some models with an eccentric lock, no wrenches are required to remove the wheel. On children’s or budget models, the wheel is fixed with two nuts, so wrenches are required.
To tighten the cone, or to eliminate the backlash, you will need: a 17 mm key and a 15 mm key. First, loosen the locknut, then tighten or, conversely, loosen the flare nut until the desired result is obtained. As a result, we achieve the elimination of backlash and then tighten the lock nut.
Poor quality parts will cause the hub axle to bend or break. Only a replacement with a different axle, of a higher quality, will be the best way out of this situation.
Bushing lubrication (maintenance)
A tightly running wheel means the hub bearings require maintenance. To reach the bearings on the bushing, you must first remove the sprockets. This can only be done with a special puller. It is allowed to lubricate the bearings with liquid grease, filling it with a medical syringe.
Teflon-based grease has proven itself well. it is a widely used grease that is effective, versatile, and not the most expensive. However, this grease evaporates easily, so green grease can be mixed with Teflon grease to increase the viscosity.
A crunchy sound of a spinning wheel after assembly means that sand has entered the bearing, or defects have appeared on the rubbing surfaces. Disassemble and lubricate again or replace defective parts.