Types and design of bicycle hubs
Before doing anything with the bushing, you first need to understand its design. How to change the hub on a bicycle will become clear when you understand its design. All bushings have 4 main components:
- Housing. The spokes are attached to the body and connect it to the rim. The body has cups on the sides, into which the bearings are inserted, it is hollow inside. An axis passes through the body.
- Bearings. There are two types: bulk. balls fill the cups of the body; industrial bearings. the balls are housed in a closed structure and are a one-piece bearing. Sometimes there are balls of a non-closed type that are simply fastened by a metal shape. Bearings allow the housing to rotate around an axis.
- Axis. The connecting link of the bicycle and the wheels, bearings with the body revolve around it. The axis itself remains stationary. The fastening system can be nut or eccentric. An eccentric is used on vertical dropouts to facilitate wheel removal, sometimes nuts are used on cheaper models with such dropouts. Nuts are needed on horizontal dropouts where there is no chain tensioner and single speed transmission to make it easier to center the wheel and tighten the chain. The eccentric axis is hollow with a hole inside, through which the eccentric is attached.
- Retaining nuts, eccentrics, locknuts and guides. The guide is screwed onto the axle thread first so that the bearings remain in their position. The locknuts fix the position of the rail on the body. The nuts are screwed onto the axle from the outside of the dropouts to secure the wheel position. Eccentrics perform the same function.
This design completely describes the front hub, but the rear hub is also part of the transmission. Rear sprockets are attached to it. Replacing the rear hub of a bicycle does not require replacing the chainrings if they are in good working order. Rear hubs differ in the type of sprocket attachment:
The sleeves also have a different number of holes for the spokes, different flange heights, different widths or O.L.D (Over-Locknut Dimension. measurement of a locknut. Length is measured with fully tightened locknuts on the hub (not on dropouts) from one locknut to another). You need to choose the right hub for your dropout width, chainline and the number of spokes on the rim.
In order for the bushing to last for a long time, it must be regularly serviced. Maintenance consists in cleaning the bearings and housing cups from old grease that has already collected enough dirt. Black grease indicates dirt. This grease must be changed to prevent dirt from destroying cups and bearings.
When you have completely disassembled the bushing, wipe off the old grease with a rag or paper from the bearings and bushing housing cups. Apply new grease to cups and bearings. Next, assemble the structure.
Disassembly and replacement of parts of the front hub of the bicycle
To carry out the parsing procedure, you need several wrenches. Wrenches 13, 14, 15, 16 and 17mm may be needed. The most commonly used wrenches are 14 and 15 mm. Sometimes a thin pair of wrenches are required to remove the small locknut and not damage the structure.
Remove the retaining nuts from the dropouts. Most often a 14 mm wrench is needed.
Remove the wheel from the bike. If you have a rim brake, you need to remove the pads so that the wheel can be removed.
Unscrew the locknuts. Here you need 2 keys, lock nuts can be for different key sizes and for different widths. It is necessary to hold one key on the thread of the guide, and unscrew the lock nut with the other.
Remove the guide and pull out the axle. At this point, the guides can be removed by hand.
Advice: if you cannot remove something, then do not rush to do it with great force, so as not to break the tool or sleeve. Perhaps some detail matched the other. With this problem, you can use the anti-procotic chemistry WD-40.
Pull out the bearings carefully. If you have them of a bulk type, then prepare the place of work so that they are not lost. The balls are not connected to anything in any way, so they can easily fall out and get lost. If you have industrial bearings, you will have to gently pry a thin plastic part with something to get to the balls.
Tip: Separate the balls from the right cup and the left cup, most likely they are already slightly deformed. In order not to propagate the deformation to another cup, it is best to always insert the bearings in their previous place.
Replace the bearings. Spread the balls evenly around the edges of the cup if you have a mound. Industrial just enough to slide into place.
Insert the axle, tighten the guides and locknuts. Make sure that the axle protrudes from the cups without distortions in length on one side. Slide the guides and locknuts onto it. If you have loose bearings, then a dilemma may arise: tighten tightly and eliminate the play, or leave play, but allow the bearings to rotate freely. If the backlash cannot be eliminated without strong twisting, then it is best to leave a small space, but not bring the hub to a state of complete deformation while driving.
Replace the wheel and tighten the nuts. Make sure that the wheel is level, without distortions.
How to disassemble and replace a part for a rear hub on a bicycle
The rear hubs are part of the drivetrain, so they have an additional mechanism that depends on the type of bike drivetrain:
Before asking the question: how to change the hub on the rear wheel of a bicycle, you need to identify the cause of the breakdown. To do this, first disassemble it according to the instructions in accordance with the type in the bushings
Rear ratchet hub. The principle of operation is the same as with the front one, but after dismantling the wheel from the bike (after Step 2.), you need to remove the ratchet with a special puller and a wrench and continue with Step 3.
Rear hub for cassette. After dismantling the wheel (Step 2), remove the cassette with a special puller and a whip. Dismantling the drum consists in removing the locknut and the guide, after which you need to carefully remove the drum from the axis.
The fixed and single speed hubs are disassembled in the same way as the front ones, you don’t even need to remove the sprocket. If you have a BMX, then you have to remove the driver, it is removed according to the principle of a drum for a cassette. Sometimes there are single-speed bushings with a foot brake, for example, on a bicycle Ukraine, there you also need to pull out the brake mechanism.
The planetary hubs are very difficult to service due to their complex design, they usually do not require maintenance at all due to the closed mechanism. There is no single principle of maintenance of all planetary systems; each model should have its own instruction. The process is something like this: after unscrewing all the nuts, you need to remove the housing cover and remove the core. If you managed to do this, then you need to disassemble all moving mechanisms for service. It is important to remember how everything was originally, if you are doing it for the first time, so that you can collect it.
Bicycle hub replacement
The hub is an essential part of the bike design. Both bushings support the entire weight of the rider and the bike itself. All loads during landing and impacts in case of unevenness are also taken over by the hub. Therefore, breakdowns due to which the hub is replaced on a bicycle are very common.
In this article, you will learn how to change the hub on the rear and front wheel of a bicycle, we will understand the types of bicycle hubs and talk a little about their maintenance.
Do not rush to change the entire bushing at once, first identify the breakdown. Sometimes you can get by with replacing just one part: a bearing, axle, drum, or even one nut. The cost of one part will be much lower than the whole bushing. Disassemble the bushing, identify the breakage and replace the defective part.
If the body is deformed so much that further operation of the bushing is impossible, then you will have to change it completely. In such a situation, you will have to re-spoke the wheel, i.e. remove all the knitting needles from the hub and rim and put everything back on, if you don’t mind the knitting needles, you can simply cut them off with wire cutters.
If you are faced with a squeak, but there is no time for serious and thorough repairs, you can use partial lubrication.
1-Piece Crank Replacement, BBT Bearing Repack on Cruiser Bike
It will not eliminate the problem completely, but will only allow you to postpone its solution for a certain time.
Like pain pills, it will relieve pain, and when you have the opportunity, you will undergo a full course of treatment.
Any liquid lubricating oil will work for you. This method does not require unscrewing the pedal from the crank arm. Lay the bike on its side with the end of the pedal facing up. Remove the plug covering the hole where the bushing is located. A knife or screwdriver is suitable for this. Then slowly pour 2-3 ml of oil inside the structure. In this case, you need to slowly rotate the pedal so that the lubricating fluid penetrates into the mechanism. Then replace the plug and quickly rotate the pedal again. Finally, lift the machine onto the wheels and rotate the part several times again.
This will help to get rid of unpleasant sensations during driving and difficulties in rotation for a certain period of time. However, pretty soon the oil will leak out, and the above symptoms will manifest themselves. Therefore, for a high-quality treatment of bicycle pedals, a complete disassembly of the mechanism will be required.
Step-by-step instructions on how to remove a pedal from a bike without a puller
After finishing the preparatory work, we proceed to dismantling:
- First of all, slide the system towards the steering wheel, this position is considered to be working.
- Gently unscrew the pedals from the crank with an adjustable wrench. Which way to unscrew the pedals on the bike? Right. counterclockwise, left. in the direction.
- Remove the end cap to expose the locknut. Use a small flat head screwdriver for this action.
- Smoothly unscrew the nut, holding the axle with the second key.
- Also, a washer remains at the end, which must be removed.
- At this point, unscrew the cone.
- It remains to remove the platform from the axle, try to control the position of the bearings in order to exclude their sudden fall.
Difficulties during dismantling arise due to external factors or under heavy loads. There are two options for solving these problems:
- treat the elements with kerosene or solvent. After soaking in such liquids, dirt that hinders rotation can be easily removed;
- you can heat the axle and connecting rod, there will be a slight deformation of the metal, and the axle can be easily removed along the thread.
In general, the process of removing the pedals is quite simple, it is much more important to prepare the necessary tools and materials, as well as follow the instructions. It is recommended to return the parts to their place first by hand, and only at the end to tighten with special wrenches.
Guys, welcome! In this article, we’ll talk about pedals. I want to say right away that there is a pedal on the left side and on the right side, and they differ in the direction of the thread.
It is quite easy to identify them: you sit on the bike and know that there will be a left pedal under your left foot, and a right pedal under your right foot. Due to the fact that they have a different thread direction. they unwind in different ways, and twist in different ways.
Example: The right pedal is unscrewed counterclockwise and the left pedal is unscrewed clockwise. The right pedal is twisted clockwise, the left pedal is twisted counterclockwise. It is important to remember!
When you twist the pedals, thereby installing them in the connecting rods, you need to lubricate the thread itself with grease, otherwise there may be a problem when unscrewing this pedal in the future. If this happens, I advise you to use the WD 40, it should help.!
Cottered Crank Removal. Old Raleigh. BikemanforU Tutorial
But there are times when the pedal does not want to unscrew, then you have to use an angle grinder. In this case, the cranks will become unusable, but you can reach the pedal. You can use other methods that come to your mind, the main thing is not to despair, but also not to allow stupidity.
Remove the rear sprocket
On the rear sprocket, the thread direction is normal.
Place the key-whip on the sprocket as shown in the figure with the part of the chain that does not hang down.
Wrap the key chain around the rear sprocket, pull the chain in the opposite direction of the wrapped chain.
Rotate the key counterclockwise vigorously to remove the sprocket. If it is difficult to do it yourself, then ask someone to help you. It is necessary to ensure that the chain stays on the sprocket.
Now about the lubricant!
Various bearing substances can be used as a lubricant. Litol-24 is perfect. Its advantage is that this type of grease does not lose its properties even in winter.
Apply grease to the place where the balls of the second bearing were located. The amount of material will be sufficient, which will help to glue the balls motionlessly.
Then carefully install the balls themselves and insert the axle without moving the spherical structural elements.
How To Remove a Bicycle Crankset Easily. Road Fixie MTB Bike Crank
After that, turn the bike pedal over, making sure that the axle does not fall out, and lubricate the ball cup for the first bearing. After installing them, tighten the cone, put the washer and locknut in place.
As you can see, the procedure for disassembling and lubricating the pedals is not difficult. It is important to be careful and follow instructions.
Then you will provide yourself with a comfortable ride and extend the life of the bicycle pedal hub.
For more information on disassembling bike pedal grease, see the video below:
Useful to pay attention
Cleaning / lubricating the chain and sprockets Checking / adjusting the gear shift system Disassembling / lubricating / pulling the wheel axles Disassembling / lubricating / pulling the pedal bearings Disassembling / lubricating / pulling the pedal bearings Disassembling / lubricating the steering column bearings Dismantling / lubricating the rear gearshift system (derailer / repair) ratchetsCheck chain wearChain replacementChange the pedalsSpeed and straightened “eights”. The only thing that I have not tried to do on my own, so I refer you to realbikers.ru (at the same time read other information there. a very useful site!)
- Checking / adjusting the gearshift system
- Adjusting the brakes
- Chain wear monitoring
- Lubrication / broaching of wheel axles
When the plug “dies” (or gets tired of it), replace it with something more decent.
When the pedal unit bearings “die”, replace them with a cassette.
Important! Do not lubricate without cleaning the chain and sprockets! All uncleaned dirt will fall on contacting and rubbing surfaces. Always clean before lubricating!
- Remove dirt from the chain and wipe it with a cloth slightly moistened with gasoline. Clean the inside of the links using a brush. Wipe with a cloth again.
- Clean the driven sprockets from dirt. If there is no experience, then I advise you to first rearrange the rear wheel in place of the front wheel on the front fork. Roll a cloth slightly moistened with gasoline with a loose bundle. Hold this tissue tourniquet by the ends with both hands, place the middle of the tourniquet in the gap between the two asterisks. Now it is enough to pull the tourniquet in one direction or the other. Because “ratchet” will allow the sprockets to rotate in one direction only, then very soon the gap between the sprockets and the surfaces of the sprockets will be completely cleaned of dirt. So “clean” the gaps between all the sprockets. All this can be done without removing the rear wheel.
- Clean the leading sprockets from dirt. “Clean” the sprockets in the same way as they did for the followers. Only there is no “ratchet” and you need to think a little with your head.
- Refer to the picture. Set the reverse gear selector so that the chain is on the smallest sprocket (corresponds to the 7th speed). By turning the screw as shown in the picture, adjust the position of the idler roller so that its centerline is aligned with the outer line of the small asterisks.
Complete instructions for installing and adjusting the rear derailleur
See figure. Set the forward shift switch so that the chain is on the smallest sprocket (corresponds to 1st gear on the forward shift knob). Set the reverse gear switch so that the chain is on the largest sprocket (corresponds to 1 speed on the reverse gear knob).Turn the screw as shown in the figure to ensure that the distance between the derailleur bar and the chain is no more than 0.5 mm, but also that the bar does not touch the chain.
Complete instructions for installing and adjusting the front derailleur
The hub has something like this. The picture shows the front Shimano HB-M475 hub. The KT hub mounted on the Mountaineer differs from the picture in the absence of all seals (positions 6, 4 and 8 in the figure). The rear hub is threaded for screwing on the ratchet and sprockets (freewheel).
- Loosen eccentric clamp (item 1). Remove the wheel from the bike. You may have to not only loosen the clamp, but also slightly twist the nut of the rough, so to speak, clamp adjustment.
- Unscrew and completely remove the eccentric axle (position 1).
- Loosen the lock nut 3. To do this, hold the cone 5 with one wrench, unscrew the nut itself with the second 3. Here you can find that the slots on the cone (“15” key) are not wide enough and the standard open-end wrench simply does not fit.
Attention! Don’t even try to lubricate the ratchet mechanism by pouring liquid machine oil into the ratchet slots without disassembling it! First, the oil will wash away all the dirt that has accumulated in the crevices right into the mechanism. After this disassembly of the ratchet cannot be avoided. Second, liquid oil is not a suitable lubricant for the ratchet.
Attention! There are very small metal balls in the ratchet mechanism. Don’t lose them! Work indoors and lay down newspapers!
Attention! Before you start disassembling the ratchet, decide if there is any play in it that is worth fixing. If there is a backlash, then you will need to remove the adjusting rings and, possibly, return them back. If there is no backlash, then do not “worry”.
- Remove the wheel from the bike and remove the axle from the hub.
- Unscrew the ratchet from the hub. Method 1. Use a special key. The thread is “normal”, “right”. The ratchet self-tightens on the hub when riding. And self-tightening oh-oh-oh-very well. It is necessary to unscrew it with oh-oh-oh-very great effort. The main thing is to believe that it should be unscrewed and remember that the thread is “right”!
- Unscrew the ratchet from the hub. Method 2: use a puller. Clamp the puller in a vice. The vise should be large and bolted to a good workbench. Spin the wheel rim.
- Unscrew the ratchet from the hub. Method 3: use a puller. Hold the wheel by the rim and turn the puller with an adjustable wrench. The larger the key, the easier it will be for you. It just won’t be strong anyway, because this method is the most inconvenient.
Attention! There are very small metal balls in the steering column bearings. Don’t lose them! Work indoors and lay down newspapers!
- Unscrew the cap covering the top end of the steering tube. On my bike, this cover is secured with a 5 “hex head screw.
- Loosen the screws securing the stem to the head tube. On my bike, this cover is secured with a 6 “Allen head screw. The screws are tight! A hexagon that fits into a screwdriver is not suitable.
- Take the stem off the pipe.
- Remove all O-rings covering the upper bearing. Remember in what order and how these rings mate with each other.!
- Remove the head tube from the frame tube. Catch the balls!
- Rinse all surfaces and balls with gasoline. Remove all dirt and old grease.
- Apply grease to the raceways of the balls.
- Assemble the steering column in reverse order.
- First, tighten the cap screw that covers the top end of the pipe. The cover will tighten the stem, o-rings and bearings. Don’t pinch the bearings. The steering wheel should rotate without backlash, but easily.
- Tighten the screws securing the stem to the head tube. You noticed that they were tightly tightened, it was difficult to unscrew them. Obviously, they must be tightened too hard.
You will need:
Attention! Don’t even try to lubricate the pedal bearings by pouring liquid machine oil into the pedal slots without disassembling it! First, the oil will wash away any dirt accumulated in the crevices directly into the bearing. After this, disassembly of the pedal cannot be avoided. Second, liquid oil is not the right pedal lubricant.
- On the axis of the pedal at the lever itself there are 15 “turnkey slots. Grab these splines with a barbed wire and twist. On the right pedal “right” thread, and on the left. “left”!
You will need:
The picture is taken from this document.
- Take off the rear wheel.
- Unscrew screws 8 and 9. Remember how the chain ran, how the sprocket rollers and washers were located. Please note that the screws are of different length.
- Remove bushings 10 and 11 from the sprocket rollers.
- Flush all parts with gasoline. Remove all dirt and old grease.
- Apply grease to rubbing surfaces.
- Collect everything in reverse order.
You will need:
- Using a knife or awl, carefully remove the plastic crank nut plugs on the pedals
- Using the “head” “15”, unscrew the connecting rod nuts
- Use the connecting rod puller, “squeeze” the connecting rods. First, unscrew the inner bolt of the puller so that it does not interfere with the screwing of the puller into the connecting rod. Screw the puller into the connecting rod. Now start screwing the puller bolt into the puller. The bolt will “squeeze” the axle out of the connecting rod. The error may lie in the fact that you do not screw the puller deep enough into the connecting rod (for example, if you do not remove the bolt from the puller enough). Then you will “rip” the internal thread of the connecting rod. I have no idea how after that you will take off the connecting rod.
- Twist the curly locknut with a special wrench.
- Use a 24 “wrench to unscrew the” main “nut. Perhaps, in your bike, this nut does not have a 24” wrench, but has some other devices for its rotation. Try just using a chisel, or something metallic, and a hammer. This nut is tightened with a little effort and to twist it, a lot of effort, also, does not have to be applied.
- Take out the axle. Catch the balls!
- Wash all parts with gasoline, wipe with a rag
- Lubricate the raceways of the balls with grease.
- Assemble the bearings, insert the axle, tighten the “main” nuts
- Tighten the bearings with the “main” nuts so that they rotate without play, but easily
- Screw on the counter nuts, tighten them
- Apply a very thin layer of grease to all four surfaces of the axle “square” on which the connecting rod is “pulled”
- Put on the cranks, tighten the nuts. “Stretch” the nuts with great effort. the connecting rods should “tighten” tightly on the “squares”
- Replace the plugs
Put in 3rd gear, that is, put the chain on the largest “star”. Take the chain with your fingers at the very front of the “star” and pull, firmly, but without fanaticism. If you managed to pull the chain away from the “star” by 2 mm, then it’s time to think about replacing the chain. If the chain can be pulled back a distance equal to half the height of the tooth and more, then you really run the risk that the chain can “scroll” on the “asterisks” when shifting gears. Please note that the wear of the leading “star” also leads to a similar “backlash”. And then replacing the chain will not save you. “Killed” “stars” and a new chain will “kill”.
- Take off the old chain. Place the “squeeze” on the chain (or vice versa: place the chain in the “squeeze”) so that the “squeeze sting” “looks” exactly at the axis of the chain link that you are going to “squeeze”. Twist the “squeeze” knob, the screw will be screwed in and the “sting” will squeeze the axle out of the link.
- Determine the length of the chain you need and put the chain over the large sprocket in the front and the large sprocket in the back. Loop around without passing through the rear derailer and tensioner. Add two more links. This will be the required chain length.
- “Cut off” the excess part of the chain. “Squeeze” the link axle in the right place.
- Slide the chain into place and clip it. The new chain has a loose link shaft at one end. Align the ends of the chain and “squeeze” this axis, using the same “squeeze”
You will need:
Brake shoe mounting parts diagram.
- Loosen the shoe screws.
- Pull the pads to the rim. To do this, squeeze the horns of the V-break or press the brake lever. The pads should be 1mm. from the edge of the rim and be parallel to the surface of the rim, that is, touch the rim with the entire surface.
- Tighten the shoe screws.
- There is a cable adjustment screw on the brake handle. Use it and make it so that the sum of the gaps between the pads and the rim is about 2mm. See the picture:
- Using the pad pressure adjustment screws, set equal clearances between the pads and the rim.
The pictures are taken from this instruction for installing and adjusting the brakes.
It is widely believed that in order for the brakes not to squeak, the pads should not be installed plane-parallel to the rim, but so that they “converge” by 0.5mm. It seemed to me that if you install exactly plane-parallel, using the method described above, then the squeak decreases. But the creak of the front brakes, I still could not completely eliminate.
Removing the saddle
Unscrew the bolt at the top of the seat tube. where the seat post fits into the frame.
Move the saddle with the pin out of the frame with a left-right movement.