How the bike works
A two-wheeled bicycle is a convenient, practical and useful vehicle, which has firmly established itself both in the city and in the countryside. In addition to its direct use, velik is widely used in various sports. The overall design is identical when comparing a simple city bike, Road Bikes or XC. A simple bicycle design, however, is not limited to the description of “wheels, handlebars, saddle, pedals” and includes a number of subtleties. In this article, we will dwell on the components of the bike and the belt purpose of each of them.
Drivetrain and bicycle brakes
The drivetrain is something a bike won’t run without. A fairly complex unit, it includes most of the mechanisms:
- Leading Stars;
- Cranks and pedals;
- Rear stars;
- Speed switches and coins.
The carriage assembly is located in the lower frame glass, serves as a connecting unit for the connecting rod pair and chainrings. The carriage provides free rotation without turning due to fixed bearings and a through axis on them. It is divided into two types: with open bearings and cartridge, where the entire mechanism is hidden inside the case.
Connecting rods. parts for connecting the carriage to the pedals. They can have two mounting options: slotted and square. Two-piece, or twin, connecting rods come with a chainring (stars on high-speed models) attached to the right connecting rod.
Pedals. leg supports, through which efforts are transmitted to the cranks, carriage and chainrings. Depending on the scope of application, several types are distinguished:
- Classic, or platforms. put on entry-level bicycles, you can use any footwear, engaging on the pedals due to friction forces;
- Contact. with special inserts, intended only for cycling shoes, improved grip of surfaces;
- Extreme. for a sports bike, wide surface, thickness, fixing inserts;
- Pedals with straps;
- Mini pedals.
The speed bike rear transmission chainrings attach to the rear wheel hubs. There are 2-3 rear sprockets per one chainring. Small stars are responsible for high gears, and large stars for low gears.
The connecting link between the front and rear sprockets is a chain: the Gall block model is used on the bike. The chain transfer is carried out using switches, which are controlled by a shifter on the handlebars. Shifters are divided into two types. drum and lever. Driving cables connect them to the switches.
Brakes are the most important system, without which it is strictly forbidden to roll out the bike. Modern brake systems for bicycles of various classes:
- Rim. pliers, V-brake;
Rim brakes are clamping devices with pads that act on the rims of the wheels, slowing their rotation. Pliers have one fastening, due to the movement of the lever, the staples come closer together, and when they are loosened, they move back. Pliers are placed in place of the wing attachment. Used as additional brakes on singlespeeds and road bikes.
V-brake works on the same principle, but the calipers are fixed: to the fork for the front brake, to the stays for the rear brake. V-brakes have greater accuracy and braking power compared to the clamp-on.
The disc brake consists of a disc (brake surface) fixed to the hub, a caliper and a drive. a lever and a cable. The brake pads are fixed on the caliper, which are pressed against the disc when the handle is pressed. The disc precision is higher than that of the V-brake due to the larger braking surface, less pad travel and independence from rim geometry. By the type of drive, disc brakes are divided into mechanical and hydraulic.
Drum-hub brakes are outdated, but they continue to be actively installed on road models. The drum is hidden in the rear hub and is brought into contact with the pads by pressing the pedals back. To make the sleeve rotate, a special locking mechanism is built in. Braking efficiency is low in comparison with rim and disc counterparts, but for single-speed road workers there is NO better option.
Control system and depreciation
The main element of the bicycle device is the steering assembly. It includes several components:
- Steering column;
- Steering part.
The bike fork serves as a connecting point for the handlebar and front wheel. It is installed in the front glass of the frame with a rod. The steering wheel is inserted directly into the fork, and the wheel is fixed on the ears of the legs. dropouts.
In order for the fork to rotate freely when turning, a steering column is installed inside the glass. It consists of upper and lower cups, bearings and retaining rings. Cups can be pressed or screwed onto the internal thread of the glass (on expensive professional models). Bearings are divided into closed industrial and bulk ball bearings. The rings are put on the fork rod, which is fixed in the steering column.
The handlebar of a bicycle consists of a horizontal curved tube and a vertical rod. The rudders are divided into:
- Straight (for MTB and hybrids)
- Curved up (road)
- Downward curved;
- Sheep (for road bikes).
The vertical steering rod has a wedge at the end, which fixes the pipe in the fork when tightening the nut.
The stem is a part that determines the distance of the rudder from the frame and is attached to the adjusting tube. Rigid and adjustable stems are installed on different models. Simple road bikes are NOT equipped with a stem. The distance of the steering wheel affects the fit: the further it is, the more the cyclist takes a horizontal position.
Saddle Fixed in the center tube of the frame by a seat post. Height adjustment will allow you to choose the optimal fit. Saddle widths differ depending on the type of bike: on road models they are wider than on MTB and road models. Saddles can vary in shape and length. They are spring-loaded from below or equipped with dampers.
Cushioning. Ability to dampen vibrations and cushion shock loads. Traditionally, the suspension system is located in the front fork, and these bikes are called hardtails.
The damping consists of a spring and a damper. Depending on the components used, forks are divided into several types (spring / damper):
- Spring loaded (without damper)
- Spring oil;
Adjustment of fork parameters: stroke length (Preload), rebound speed (Rebound) and lock. Forks without shock absorption are called rigid and are used on the road and road models.
In addition to standard cushioning, mountain bikes are fitted with a rear shock absorber to smooth out frame vibrations. Bicycles with two shocks are called bikes.
What the wheels are made of
Bicycle wheels are strong and lightweight structures that provide movement and, through rotation, keep the frame upright. Traditionally, the bike is rear-wheel drive, that is, the rear wheel is pushing, and the front wheel is driven and is responsible for steering.
The picture shows what a classic bicycle wheel is made of. The device is simple and has hardly changed since its inception.
Bushing. central part, consists of axle, bearings and washers. The main purpose is to set and hold torque. Transmission sprockets are attached to the rear bushings. The internal structure is more complicated than in the front ones, since the bushing is involved directly in the spinning of the wheel. On the road models, the brakes are also integrated in the rear hubs. Planetary rear hubs have hidden gearshift mechanism.
The rim is a circular ring that is attached to the hub through the spokes. The geometry of the rim, combined with the spoke tension, determines the wheel’s resistance to damage and dynamic stress. Bicycle wheel rims are made of aluminum, the spokes are made of light alloys with chrome plating. Traditionally, the knobs-regulators of the spoke tension are located in the rims, but there are also “flip-flops”, which are adjusted to the hub.
Tires consist of a tube and a tire. The chamber is a polo rubber product that is pumped with air to the required pressure. It is connected to the “outside world” by a nipple, through which air is pumped into the tire. It’s also a good idea to learn what velonippels are and how they differ. A rubber flipper is applied to the inside of the rim to protect the camera from the spokes.
The tire is the outer part of the tire and consists of beads, sidewalls and the contact part. the tread. Depending on the purpose of the bike, different types of tires are installed:
- Slick, semi-slick. for road bikes, for smooth roads;
- Road. tires with a medium tread pattern;
- Aggressive. tires with a pronounced pattern for mountain bikes;
- Hybrid: can be used both on flat surfaces and off-road (but inferior in cross-country ability to aggressive ones).
The visibility of the wheel in the dark in the rays of light is given by a reflector. an orange insert on the spokes. In connection with the requirements for traffic safety, the wheels of all bicycles are equipped with reflectors.
What holds the bike
The structure of a bicycle is similar to that of a car: there is a supporting structure on which all working units are attached. For a passenger car, this is a body, and for a bicycle, a frame. The type of frame largely determines the purpose, and its quality is responsible for the life of the bike.
The bike frame is represented by a diamond-shaped frame, welded from the elements:
- Main front tubes. top and bottom (closed), curved front tube (open)
- Seat tube;
- Top feathers;
The front tubes are “stitched” together into the head tube, the down tube and seatstays from the seatpost into the bottom bracket, and the feathers between themselves into the rear wheel dropouts. Front tubes and stays are welded to the top of the seat tube on both sides.
In relation to the seat tube, the front and rear are represented by two unequal triangles, the dimensions and geometry of which depend on the type and purpose of the bike. For the modern assortment, there are a large number of frame options, but they are all divided into classes:
- Urban. tough, durable and heavy;
- Mountain. resistant to stress, mobile, durable;
- Highway. lungs;
- Sports. resistant to high loads, durable, shock-resistant;
- Stunt. used for BMX bikes.
Bicycles are divided into full-size and foldable. The first ones do not have a complex mechanism, and they must be disassembled for transportation in the subway, public transport and the trunk of a car. Foldable have at least one joint along which the frame is folded. They are more convenient to transport and store, but are inferior to full-size ones in terms of running performance.
The material of the supporting frame has a great influence on the operation of the bicycle. Modern bicycles are available on steel, aluminum and carbon frames.
Steel is used on city bikes. The material has high strength and shock resistance, and its disadvantages are its heaviness and low flexibility, which is why the frame does not smooth out shocks well. All this does NOT have the best effect on the dynamics of the bike.
Aluminum is lightweight, durable and flexible. Compared to steel counterparts, frames from it have better maneuverability and passive damping. Lightness and strength improve dynamics and do not create significant resistance to movement. Of course, their cost will be higher.
The most expensive frames are carbon fiber. carbon fiber. This material is used on high-end road, mountain and sport bikes. Among the advantages in comparison with metal competitors are durability, strength, shock resistance and lightness. Plus, carbon-based bikes have better maneuverability compared to aluminum.
A bicycle is a fairly extensive mechanism, and consists of a large number of nodes. During operation, an important indicator is the good condition of each of them. Now that we know how a bicycle works, we can diagnose, repair and service parts.
Hub service, general bike wheel arrangement
Wheel repair machine
One of the most important parts of a bicycle is the wheels, as the smoothness and speed of the ride depends on them. They come in the following sizes (bicycle rim diameters). 20 (children), 24 (teenage bicycles for boys and girls and for extreme disciplines), 26 (mountain, city and recreational), 27 (Road), 28 (hybrid and road) and 29 inch bicycles (new standard mountain bikes).
- Read also how to choose your bike tires.
- You can also find out more information about the bike rim here.
Bicycle wheel device, its main components
- Rims. The most common material for rims is aluminum, as they have good strength. By the type of profile, the rims can be divided into:
Bicycle front wheel hub.
Hubs are the most important part of a wheel, since the quality of its rotation depends on the hub. Consists of an axis, balls, drum. The bushings are clamped in the frame drop points using an eccentric (a special clamp that can be easily removed without tools) or two nuts at the ends of the axle (you can remove it with a wrench). Different hubs for disc and rim brakes.
Bicycle spokes for wheel assembly.
Various types of nipples.
Protective rim tape.
The strength of a wheel depends on the following factors:
- Uniform needle tension;
- The quality of the rim;
- Wheel assembly quality;
- Stability of the wheel at impacts (profile)
- The number of spokes, as well as the material from which they are made.
Bicycle wheel repair is most often needed in two cases, and not Considering a punctured wheel:
- Wheel alignment (eights, eggs)
- Bulkhead and bushing relubrication.
When assembling the wheel, you will need the following tools:
- Wheel machine. a special machine that will help you assemble the wheel with precision;
Spoke wrench for wheel straightening.
When assembling the wheel, it is important to select the correct spoke length. In order to accurately select the needles of the desired length, you can use a special calculator, you just need to make a few measurements. An example of a calculator for calculating the length of the knitting needles:
Based on the calculations, you can start assembling the wheels.
- Learn to straighten the eights of a bicycle wheel with your own hands more here.
Correction of the “eight” on the rim
If a figure eight appears on the rim, then it is easy to fix it with a spoke key. An eight on the rim may mean some of the spokes are loose and need to be re-tightened periodically. In order to tighten the weakened knitting needles, we pull the knitting needles clockwise, to loosen the knitting needles. counterclockwise. Recall that the spoke wrench only rotates the nipple, the spoke remains stationary. We find the place on the rim where the rim wags, you can do this using chalk and rotating the tire. After finding the place of deformation of the rim, we tighten one side, weaken the other, while the tightening is proportional to the weakening.
Bushing lubrication (maintenance)
As you know, bushings are available on bulk bearings and on industrial bearings.
The hub should be serviced as soon as you notice extraneous sounds, tire rotation tightening, etc.
- Maintenance of the sleeve on loose bearings. It is recommended to change the lubricant every 1000-2000 km of run. In order to lubricate the wheel hub, it is necessary to remove the wheel from the bike drop points, it is not necessary to remove the camera and tires, they will not interfere. If you carry out maintenance repair of the rear wheel hub of a bicycle, you will additionally need a whip to remove the cassette and a cassette remover.
Bicycle Rear Wheel Hub Removal Tool.
- What to do if the bike squeaks when riding. Discover.
- Find out in this article //velosipedinfo.ru/kak-pravilno-nakachat-koleso-na-velosipede what pressure should be in bicycle tires.
See also how complete maintenance of the rear wheel of a bicycle is done. Disassembly, assembly of all its parts, with their mandatory subsequent lubrication.
Some helpful tips before starting:
This job will definitely require a properly sized taper wrench and lubricant, but it will also be convenient to use a magnet, an adjustable wrench and a wasp clamp.
How tight should you tighten? It is important to note that tightening the bushing bearings harder than necessary will in no way prevent them from further loosening, but will actually increase the wear of all parts. On a bushing with loose bearings, which was tightly tightened and driven on it, both the cup and the cone will most likely be damaged, and it may have to be replaced entirely. The same will happen when driving with a weak bearing tension. So how do you know when the tension is correct??
Ideally, the quick release bushing should have little knock or play when not locked into the frame or fork. This is due to the fact that Hollow will bend by a small amount when the quick-release clamp is fixed and removes this play. If there is any play in the eccentric bushings when removed from the bike, then they are most likely too tight. This does not apply to solid axles, which are secured with nuts. All of this does not work at all with bent pins or damaged cups and cones. These parts need to be replaced in order to properly adjust the bushing.
Bulkhead and bushing repair
The cup-cone bushing uses loose bearings and can be easily adjusted to their tension, unlike most industrial bearing bushings, which are NOT adjustable in any way. In them “a cup” serves as an outer ring for the bearing balls, and it is pressed into the bushing, it cannot be replaced, but “cone” serves as an inner ring and is screwed onto the axle.
Bearing balls are usually 1/4 “in the rear hub and 3/16” in the front, and they rotate between the cup and the cone. The tension of the bearings is adjusted by twisting the cone on here, then the cone is fixed in its position with a locknut (the washer between the cone and the locknut makes it easier to tighten them together). Front cup and taper bushings are usually symmetrical, although the bushing is often slightly offset to compensate for rotor mountings. On the rear bushings, a free-wheeling drum is installed (ratchet mechanism, which allows you to coast) and a cone with a locknut on the side of the sprockets can be inside the ratchet mechanism, invisible from the outside.
Bushing components cup and taper (from left to right): locknut, washer and taper.
- Cone wrenches (commonly used on 13, 15, 17 and 19mm)
- Adjustable wrench (optional)
- Wasp clip (you also need pressure to use it)
- Magnet (not necessarily)
- Clean rag
Remove the wheel from the bike and pull out the eccentric clip, be careful NOT to lose the centering springs on each side. On most bushings with loose bearings, rubber boots are installed, which must be removed to get to the cone and its edges to install the key. If you are working with a rear hub, you also need to remove the cassette. Recalculate the number of open threads at the end of the axis before proceeding to the next step. If the end of the axle has threads as shown in the photo, you can use a vernier caliper to measure.
Always disassemble the rear hub from the rotor side and the front hub from the non-rotor side. Now you need to loosen and unscrew the cones on one side of the sleeve. To do this, hold a cone of a suitable size with a wrench and unscrew the locknut counterclockwise with a second cone wrench or an adjustable wrench. You can also use a wasp clamp to hold it in a vice when loosening the locknut.
Place the wheel on a table to prevent parts from falling out on the floor, unscrew and remove the locknut, thin washer and cone from the axle. Put them in safe revenge in the order you took them off.
Remove here, slowly pulling it out from the opposite side, be careful not to lose the bearing balls when you pull it out here. Always pay attention to which side of the sleeve you are pulling out so that there is no confusion when assembling.
At this point, you must remove the cone, washer (one or more) and locknut, as well as this one. Some bushings use thick washers between the taper and locknut, while other bushings have several thin washers. Washers Not only allow the taper and locknut to be pulled together without risk of loosening the tension, but are also critical to positioning parts at the correct distance. Always Assemble the sleeve from the thread with the same washers in the same order as you removed them. Clean here and other parts with a suitable cleaning agent.
Now is the time to make sure that the cone and locknut remaining on the axle are tight enough. Hold the taper firmly with the taper wrench and check how tight the locknut is tightened with a second taper wrench or adjustable wrench.
Count the number of balls on each side before pulling them out. The front hub usually has ten 3/16 ” balls on each side, the rear hub has nine 1/4 ” balls on each side, although this is not always the case.
The magnet will make it very easy to remove the balls, but it is not necessary to use it. If you don’t have a magnet, you can simply pull the balls out with the tip of a screwdriver, or they often fall out on their own. Double check the hole in the middle of the bushing to make sure there are NO balls left inside. On many bushings with loose bearing, a metal cap is installed that protects from dust, which is pressed into the bushing (a silver ring surrounding the bearings in the photo) and It is not designed to be pulled out. Although you can remove it with a screwdriver, you will most likely damage it. Better leave it where it is.
Lubrication. Your friend. Place a thick strip of grease on the inside of the cup, it should completely cover the entire perimeter. This will also help to hold the bearing balls as you reassemble the bushing. Gently insert balls on both sides of the sleeve, there should be exactly as many balls as you pulled out when you took it apart.
When the balls are in place, you need to insert here. Before doing this, apply grease to the surface of the cones where the balls will roll. Pay attention to which side you will insert it, you need to insert it from the side from where you pulled it out. Insert into the front hub from the side of the rotor, and into the rear from the side of the freewheel drum. Be careful not to drop the balls out of the cups.
Screw on the cone, after having lubricated its surface in contact with the balls with a layer of grease, then install the required washer and locknut. Twist the cone clockwise until it touches the balls and then unscrew it a quarter turn.
Hold it in place with the taper wrench and tighten the lock nut against it with the second wrench. The bushing will most likely need to be adjusted further, but it is important to remember that while the wheel is not Fixed with a clamp, the bushing with an eccentric clamp should not be up to the end of the bearing clamping, there should be a slight play, and after installing and fixing the clamp there should be no backlash. This is due to the fact that the Hollow here with an eccentric clamp is slightly compressed when it is fixed with a clamp.
Twist the eccentric bushings here with your fingers. It should rotate freely, smoothly, evenly, but with little play. Place it on the frame or fork and try to noticeably play by holding the top of the wheel and swing it along the axle. If there is no play and the wheel spins smoothly and evenly, you are done. If not, continue with Next steps.
Remove the rubber boot from the bushing and eccentric clamp spring (so that the QR clamp nut only comes into contact with the outer bushing locknut) and secure the wheel to the outside of the rear triangle of the bike, the side you are adjusting should be closer to you. With this attachment, the eccentric clamping force should be approximately the same as when the wheel is mounted on the bike during a ride.
Place one hand on the cone and locknut on your side and the other on the rim. Gently rock the rim back and forth axially and try to feel the play in the bushings with your other hand. If you feel any tapping, you will need to slightly preload the bushing bearings.
With one hand, gently hold the cone in place, and with the other, release the locknut, return it counterclockwise. When the locknut is loose, turn the wrench on the taper clockwise approximately ten degrees. Hold the cone in place with a wrench and tighten the lock nut. Check for any play as described in step 15 and if there is still play, repeat the process until it disappears. Save time and make adjustments in small steps, you will most likely need to do this several times before the adjustment is perfect.
For the final check, slightly open the eccentric handle of the clamp (so that it is at an angle of 45 degrees, but at the same time keeps the wheel in the dropout) and check the hub play, keeping one hand on the axle. There should be some play, but it should disappear when the clamp is tightened.
Recalculate the number of threads on the protruding part of the axle on each side to make sure they are the same as before disassembling the sleeve and that the number is the same on both sides. Wipe off any excess grease.
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:
- “Clips” in the pedals. difficult rotation or cranking;
- The connecting rods are loose;
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 secure the bike.
2. Unscrew the locking 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.
3. Using a puller, twist them off the axis. It will take considerable effort here.
4. Pull the cups out of the glass using a carriage puller. The first is to unscrew the cup from the side opposite to the stars. Then extract here.
5. Remove the bearings, inspect and replace damaged parts.
6. Clean in kerosene, refit and lubricate. When installing, carefully monitor the position: on one side, the bearing is put 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 means 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, adjustment is NOT required.
Varieties and replacement of bicycle bearings
- Types of bicycle bearings
- Maintenance and replacement of carriage bearings
- Disassembly and replacement of bearings on the front fork
- Replacing wheel hub 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 bushings, steering column and more complex devices. ratchet, switches, rear shock absorbers.
Types of bicycle bearings
By the type of construction, parts are divided into two types: rolling and sliding.
Rolling bearings are two mating parts with grooves, into which rolling bodies are inserted. balls. Their even distribution helps to minimize friction in the assembly and, accordingly, 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 slip is not allowed. steering column, bushings, carriage. Can be installed in complex mechanisms. shock absorber hinges and switch rollers.
Plain bearings are ballless parts. They are two elements, which rotate tangentially to each other. Materials for manufacturing. bronze, steel alloys, metal plastics and everything that has a low coefficient of friction.
Compared to a rolling bearing, they are less resistant to abrasion, since the two parts interact directly with each other. Wear provokes the appearance of a gap, 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. open type parts. They are represented by a cup in which balls are distributed along the grooves, 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:
- Easy to remove and install;
- Can be adjusted in the field;
- Let’s change the components separately.
Disadvantages include frequent adjustment and the need to clean up trapped dust and dirt.
Prom bearings do NOT require adjustment, lubrication or cleaning. The location of the balls, the amount of lubricant in the closed housing remain unchanged. Water and abrasive gets inside the cartridge.
However, if the bearing is worn out, it will need to be replaced entirely. Far from civilization, this is problematic. The price of “speeches” 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 in comparison with their metal counterparts. In addition, they are better able to withstand temperature changes. Parts of this type are installed on high-end bicycles.
Replacing wheel hub bearings
The hub is not just the rotation of the wheel. Without the built-in hinge 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.
Disassembling the hub is as easy as disassembling a fork. For the rear wheel, the procedure will be a little more complicated than for the front, since you will first need to remove the cassette from the sprocket. On a single-speed bike, the retaining ring and the sprocket itself are dismantled.
In general, the disassembly looks like this:
1. Remove wheels from dropouts.
2. Dismantle the sprockets using a cassette puller and a locking whip. On the singlespeed, open the stopper with a screwdriver or special spreaders.
3. Using a 15 wrench Unscrew the fastening nuts. For the rear wheel hub, unscrew the nut on the side opposite to the stars.
4. Remove washers and bearing assemblies. Bulk ones are being moved, industrial ones are being replaced by new ones.
5. Clean parts and replace damaged components.
6. Pull out the wasps, 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 misalignment of distortions, the details should exactly fall into their rightful places. It is NOT advisable to swap them during bulkheads. This threatens backlash and deterioration of 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 “speeches” the assembly itself is not necessary to lubricate, only the inner cavities of the bushing, and so After installation, we check the performance of the wheels: smooth running without play and clamps indicates that the parts are installed correctly.
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 to change the bearing of 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:
- Flip the bike over and Unscrew the front wheel.
- Place the bike in its 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 cages, so be careful not to scatter balls.
- 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 club and the lock nut are thrown. Checking the tightness of the glass: when tilting the bike, the front wheel should deviate from the straight position by 15. 20 degrees. If it practically does NOT move, loosen the hinge. A large deflection of the wheel indicates a weak tightening, and the glass needs to be tightened.
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 driving performance and travel safety.
How many balls are in the front hub of the bike
Details of bicycle bushings of the “cone-cup” type. From left to right: lock nut, thin washer and taper.
Helpful hints to help you in your work:. How To Tighten The Bearing?
Note that overtightening the bushing will not prevent the bushing from spinning, but will accelerate wear on the bearing components. Riding with an overtightened bushing will likely damage both the cone and the cup, so in the end the bushing will have to be replaced completely. A similar result will be brought about by driving with an unnecessarily weakened bushing.
Ideally, hollow axle bushings and eccentrics should have a little slack, since K. When attaching to the bike and snapping the clamp, the wheels bend slightly, which compensates for its backlash. If there are no backlashes in the bushings removed from the bicycle, this means that it is overtightened. This does not apply to monolithic axles on which the wheels are clamped with nuts. In this case, if the cup with a cone is bent or damaged, the sleeve can only be thrown away. If necessary, replace the damaged parts and proceed to bushing adjustment.
What you need:
- Taper wrenches (most common sizes: 13, 15, 17 and 19 mm).
- Adjustable wrench (optional).
- Clamp (pressure) for clamping the wheel axle (optional).
- Magnet (optional).
- Clean rag, cotton swabs.
Everything is ready? Then let’s get started.
Remove the wheel from the bike and pull out the eccentric clamping mechanism (don’t lose the two centering springs). In most bushings with loose bearings, rubber or plastic caps are used, which must first be removed to gain access to the splines of the cone. If you are working with a rear hub, you will also need to remove the cassette. Count the number of open threads at the ends of the wheel axle before continuing. If here is without thread, as in the photo, Measure the distance from the end of the axis to the nut with a ruler or vernier caliper.
Always start disassembling the rear hub on the opposite side of the bike (i.e. the left side of the bike) and disassembling the front hub on the opposite side of the brake disc (right).
First you need to unscrew the taper from one end of the sleeve. Hold the cone with a flare wrench and unscrew the locknut counterclockwise using a flare or adjustable wrench. If you have a special (pressure) clamp, use it to fix the axle.
Lay the wheel with the weakened side of the hub up so that the parts do not fall out, then completely unscrew the locknut, Take out the thin washer and the cone. Put them somewhere where they will NOT get lost.
Grasp the opposite side here and pull it out of the hub body, being careful NOT to lose the balls. Always pay attention to which side of the sleeve you are pulling out from here to avoid assembly problems.
So, you have already removed the cone, washer, locknut and took it out here. Clean the removed parts well from old grease and dirt. It should be said that in some bushings there is one thick washer between the cone and the locknut, in others there are several thin washers. Washers Not only prevent the locknut and taper from loosening, but also provide adequate clearance between the bushing parts. Assembling the bushing, always use the same washers, placing them in the same order as they were in disassembly.
Now you can check if the bushing is tightened correctly from the opposite side. While holding the cone with a flare wrench, check how well the locknut is tightened by turning it clockwise with a second wrench.
Count the number of balls on each side of the bushing before removing them. The front bushings usually (but not always) use 10 balls, the rear bushings use 9.
The balls can be pulled out of the bushing cup using a magnet or a magnetized screwdriver. If you do not have a magnet, simply pry out the balls with a thin screwdriver. Check the hub cups again to make sure you DO NOT forget the balls inside. Many cone-cup bushings are fitted with metal anthers (the silver ring surrounding the balls in the photo above). Anthers are usually pressed into the sleeve, so it is best to leave them alone.
Your task now is to remove any old grease, dirt and small metal particles that may be on the inner surfaces of the bushing. To do this, use a cloth wrapped around your finger or cotton swabs. Now it’s time to carefully check the friction surfaces of the cup and cone. They must be smooth and free from pitting or uneven wear. If you notice damage to the cone, you need to replace it with a similar new one (there are many different sizes, so choose carefully). Unfortunately, nothing can be done with a damaged cup. it is firmly pressed into the sleeve body. Sure, a thick layer of grease will help for a while, but a badly worn cup is a sure sign that the end of the bushing is near.
I do not regret lubrication. Cover the concave surface of the cup with a thick layer of grease. The grease will also help hold the balls in place during reassembly. Carefully place the balls in the cups on both sides (don’t you forget how many there should be?).
Once you have inserted the balls into the cups, start setting the axis. Before assembly, apply grease to the friction surfaces of the cone. Insert from the same side as filmed: for the rear hubs, this is the side of the bike opposite the cassette, for the front hubs, vice versa.
Put the cone in place, put the washer and locknut on the axle. Turn the cone clockwise until it contacts the balls, then release it a quarter turn.
Hold the cone with a flare wrench and tighten the locknut. The hub will most likely require further adjustment, but remember what was said earlier: eccentric hubs removed from the bike should be slightly loose. After installing and fixing the wheel on the bike, the play will disappear.
Turn the eccentric bushings with your fingers. it should rotate smoothly, but have barely perceptible play. Place the wheel on the bike and shake it slightly: if the wheel rotates freely and you DO NOT feel any backlash, everything is fine, your work is over. If not, see Next Steps.
Remove the rubber bushing boots and eccentric wheel clamp springs (the clamp nut should only contact the outer surface of the bushing locknut). Fasten the wheel to the outside of the frame (see photo), insert one end of the hub axle into the corresponding slot in the dropout. Clamp the eccentric with the force with which you usually clamp it when driving.
Grasp the cone and locknut with one hand and wiggle the wheel slightly with the other. If you feel a knock in the cone, this means that you need a little preload bearing.
Hold the cone with one wrench and with the second. Loosen the locknut by turning it counterclockwise. Once you release the nut, slightly (10 degrees) Turn the wrench holding the cone clockwise. Hold the cone in this position while tightening the locknut. Check the bushing again for any looseness (Step 15). if you feel a knock, repeat the adjustment until it disappears.
One final check: Release the eccentric wheel clamp lever a little (about 45 degrees. it should still hold the wheel on the dropouts) and check the hub by slightly wobbling the wheel. there should be barely noticeable play. When tightening the eccentric, the backlash should disappear.
Make sure that the wheels are evenly visible on both sides of the hub: the number of visible threads on both ends of the axle should be the same. Also compare the number of turns before and after disassembly. it should also be the same. Wipe off excess grease. All.