Removing the carriage of cartridge and collapsible types
Before removing the carriage from the frame, both connecting rods must be removed from the carriage axis. The bottom bracket should then be cleaned of any dirt, as the frame bottom bracket is one of the dirtiest areas on a bike and is usually difficult to clean until the cranks are removed. Especially carefully it is necessary to scrape the dirt out of the cup slots. if there is a lot of dirt, then it is impossible to insert a stripper into the cup.
Removing the carriage may require considerable force. Therefore, the bike must be securely positioned. If it is more convenient for you, you can turn it upside down.
We begin to remove the carriage from the left side, that is, where there are no stars.
Some carriages have a lock nut on the left side. It must be turned off special. with a key (if it is not there, then it is possible with an ordinary family member). This nut has a right hand thread. Unscrewing may require considerable force. It is necessary to unscrew carefully, not allowing the key to break off. you can damage the nut.
If your carriage does not have such a nut, then go to step 2.
Now we take the key for the carriage (slotted or special, depending on the design of your carriage. The photos show the slotted one.) Insert it into the slots, and turn the left adapter cup out of the frame with an adjustable wrench with a longer handle. It has a right-hand thread. Unscrewing may require considerable force.
We take out the left cup (together with the bearing, if the carriage is collapsible)
Move to the right side of the bike (where the sprockets are). Again we take the carriage puller and the long-handled key, insert it into the grooves, and turn the right cup out of the frame. It has a left-hand thread. Unscrewing may require considerable force.
We take out the cartridge or the right cup with the axis.
The carriage is removed. Now you need to pull out the bearings from the collapsible carriage (if they are not pressed into the cup), remove the old grease with a rag, and rinse all the parts in some solvent (usually kerosene).
Installation of the cartridge-type carriage is performed in the reverse order of removal.
We start by applying a little grease to the carriage and adapter cup threads, so that later it will be easier to turn it out.
We start on the right side. Using the carriage wrench and adjustable wrench, screw the carriage into the frame until it stops. The moment should be 50-70 Nm.
The carriage on the right side has a left-hand thread.
We pass to the left side. Use the same key to screw in the left adapter cup. The cup on the left side has a right-hand thread. The moment should be the same. 50-70 Nm.
Now you need to install the connecting rods and the system.
Depending on the carriage glass of the frame, carriages are divided into the following types (the most common):
- English thread (BSA, 1.37 in x 24 TPI) is the most common standard. Options depending on the length of the glass:
- 68 mm. most common,
- 73mm. used on a range of mountain bike models,
- 83 mm. for extreme disciplines,
- 100mm. fat bikes.
- With Italian thread (BSC, 36 mm x 24 TPI), tube length 70 mm. used in old road bikes. Still (2013) in use by Campagnolo.
- With French / Swiss thread M35 × 1. used in Soviet bicycles.
Cycle days Not a day without a bike!
They are part of an integrated system. They are two cups with bearings pressed into them, screwed into the bottom bracket of the frame. In this case, the bearings, as a rule, are located outside the carriage sleeve, and the axle is pressed into one of the connecting rods and has a greater thickness, which achieves a high rigidity of the assembly. The cups are interconnected by a plastic or aluminum spacer that provides bearing preload and protection from dirt.
Road and mountain carriages, as a rule, are incompatible with each other, even from the same manufacturer.
- Shimano Compatible:
- Shimano Hollowtech II
- RaceFace X-Type
- Chris king
- FSA Mega Exo
The homemade carriage on the bicycle I assembled consisted of an axle and two 203x bearings driven tightly into the frame. Those were the times 🙂 Now the carriage has become much more complicated. Let’s try to deal with this tricky thing.
The bottom bracket is a bicycle assembly that connects the system to the frame and rotates freely using bearings (usually cartridge bearings). The carriage is screwed or pressed into the carriage glass of the frame. Separately, eccentric carriages can be distinguished. they can be displaced in the carriage glass of the frame in order to tension the chain on a singlespeed or on a bicycle with a planetary hub. Requires a special frame.
They include an axle onto which the connecting rods are pressed, and a set of bearings located inside the bottom bracket of the frame. They are divided into two categories:
- Cartridge. axle and bearings form a single non-separable unit.
- Dismountable. can be disassembled for cleaning, lubrication and replacement of worn parts (used in old bicycles).
- Wedge-fit connecting rods (Soviet bicycles).
- Under the square (square taper). the standard “floats” somewhat from different manufacturers.
- With spline fit of connecting rods:
- Shimano Octalink v.1
- Shimano Octalink v.2
- Truvativ Powerspline
- Truvativ Howitzer
- Truvativ HammerSchmidt
All of these standards are generally incompatible with each other.
The carriage is installed in the reverse order of removal.
When assembling the carriage, the most difficult thing is not to confuse the ends of the carriage axis. its right and left sides are different. Usually on the axle or on a plastic casing (this casing is not provided on some carriages) letters are applied corresponding to the sides of the axle.
The cups cannot be confused. they have different threads (the left cup has the right one and vice versa)
We put a plastic cover on the axle. We put the bearings in the cups. If the bearings have cages, then we lay them out with a cage (balls. inside the cups). Lubricate the bearings with a thick grease With the same grease we grease the threads of both cups.
We start assembling from the right side. We insert the axle into the right cup, and screw this cup into the frame until it stops. This requires a slotted wrench for the carriage. The right cup has a left hand thread.
Now screw the left cup in the same way on the other side. It has a right-hand thread. Let’s move on to adjust the carriage. (you can go directly to step 1)
In this article, we will analyze what kind of bearings are used in a bicycle, and how they differ from each other.
In fact, a bearing is a product that is part of a support or stop that supports a shaft, axle or other movable structure with a given stiffness. It also gives an easy rotation of the bicycle mechanisms, ensures the operation of its main units, a clear fixation of individual parts.
According to the principle of operation, all bearings used in a bicycle can be divided into three types:
- Rolling bearings
- Plain bearings
- Ceramic bearings
Rolling bearings consist of two rings, rolling bodies (of various shapes) and a cage separating the rolling bodies from each other, holding them at an equal distance and directing their movement. Bicycle rolling bearings are divided into two types:
bulk (“cone-cup”) and industrial (non-separable (“cartridge”)).
Each type has its pros and cons.
The advantage of bulk bearings is their simplicity and the ability to adjust them. Unfortunately, the latter quality is also a big drawback, since the possibility of adjustment obliges you to perform it regularly. Adjustment is carried out with a flare nut. With its help, the clamping force is selected. Bulk (“cone-cup”) is a set of balls that roll on a cup, removable or pressed into the body of a part.
You need to be careful, because if the force is too low, the bearing will have a play, and if the force is strong, the wheel does not spin well (this can lead to rapid wear of the bushing and poor roll-up).
Industrial bearings (non-separable (“cartridge”)) are a non-separable unit with two rings, between which balls roll. Such bearings are pressed into the seat and can be replaced if necessary. In industrial bearings, adjustments are generally not required.
The disadvantage of industrial bearings is the higher price (compared to bulk bearings). If dirt gets into the bearing, it will not be possible to fully rinse it. Most likely, a replacement will be needed. In this regard, bulk bearings have a complete advantage. even in the field, they are easy to wash and lubricate.
Both types of industrial bearings can use a cage that creates a spacing between the balls and keeps them from falling out.
A plain bearing is a support or guide of a mechanism in which friction occurs when the mating surfaces slide. The design of such a bearing is a pair of rubbing materials with a low coefficient of friction.
Over time, a material that wears out softer and a backlash occurs, then the part needs to be replaced (most often its design provides for replacement). These bearings are used in the construction of inexpensive pedals as well as rear derailleur rollers.
Plain bearings require regular overhaul and replacement of worn elements; they are widely used in assemblies that do not experience heavy loads and impacts and in assemblies where there is no requirement for backlash.
The most common type of such bearings is mixed or hybrid, in which only balls (or other body of revolution) are made of ceramics, and both rolling rings are made of steel. This is the most common option in the cycling industry. Cage in hybrid ceramic bearings made of low friction synthetic materials.
There are also bulk ceramic (ceramic balls are used) and sleeve bearings (for rear derailleur rollers).
Such bearings have a number of advantages:
They can work at high temperatures, which, of course, increases the speed of work. Ceramics are not subject to corrosion, as well as aggressive acidic and alkaline environments. It does not magnetise, does not transmit electricity, it has higher elasticity and hardness. All characteristics of ceramics are superior to steel. However, if you look at it, then in fact the gain is only in weight.
Other advantages of ceramics over steel, such as resistance to aggressive environments or high operating temperatures on a bicycle, are not needed. Corrosion resistance is a big plus. But, to a greater extent, this applies to bearings made entirely of ceramics, mixed ones are still susceptible to corrosion. The cleaning intervals for both steel and ceramic bearings are the same.
When buying bearings, remember that there are no good bikes without good bearings.
Lack of lubrication, incorrectly selected or installed bearing can not only cause damage to the bike, but also lead to an accident and become a serious threat to its owner.
Front fork damping system
It is the presence of a shock absorber that allows the biker not to pay attention to obstacles and makes the bike passable. A good shock absorber resists the reaction of the support to the front wheel in a timely manner, so the fork must be kept in good condition
How to lubricate shock absorbers
Normally, it is necessary to lubricate the “legs” of the plug after 150-200 kilometers, after 700 kilometers (on average) the oil seals are disassembled and lubricated, and annually or after running 3-4 thousand kilometers. the oil in the shock absorber is completely replaced.
It is better to show all the care of the fork in the video than to describe it in detail in text. For example, here you can see all the preventive maintenance operations for the front fork and shock absorbers:
Replacing wheel hub bearings
The hub is not just a wheel pivot. Without the built-in articulation mechanism, forces would be transmitted unevenly to it, and the bike would not be able to move. The same symptoms appear when the bearings are worn out.
Disassembling the hub is as easy as disassembling a fork. For the rear wheel, the procedure will be slightly more complicated than for the front wheel, since you will first need to remove the cassette with sprockets. On a single-speed bike, the retaining ring and the sprocket itself are dismantled.
In general, the disassembly is as follows: 1. Remove the wheels from the dropouts.
Dismantle the sprockets with a cassette puller and a locking whip. On single speed open the stopper with a screwdriver or a special spreader.
Unscrew the fastening nuts with a 15 wrench. For the rear wheel hub, unscrew the nut on the side opposite to the stars.
Pull out washers and bearing units. Bulk ones are being moved, industrial ones are being replaced by new ones.
Clean parts and replace damaged components.
Pull out the axles, wipe the inner cavities of the bushings.
It is important to place the bearings correctly and press the cones in the same way as before disassembly. In no case should it be skewed, the details should fit exactly into their rightful places
It is not advisable to swap them during a bulkhead. This threatens with backlash and deterioration of the wheel travel.
New bearings are selected in advance according to the old ones. they must be the same as they were before the repair. Lubrication is the key to rebuilding and replacing (in the case of “bulk”). When installing the “flush”, the assembly itself does not need to be lubricated, only the inner cavities of the bushing and the axis. After installation, we check the performance of the wheels: smooth running without play and clamps indicates that the parts are installed correctly.
Maintenance and replacement of carriage bearings
Periodic cleaning, lubrication and replacement of worn parts will help prevent sudden movement problems on your bike. Signs of a faulty carriage condition:
- “Clamps” in the pedals. difficult rotation or cranking;
- connecting rods dangle;
To remove the connecting rods and carriage cups, you will need special tools. pullers and an internal hex wrench. The dismantling process is as follows: 1. Turn over and fix the bike.
Unscrew the retaining nuts with a hollow wrench. You can also use a hammer with a chisel, however, the nuts must be knocked out carefully so as not to damage the connecting rods.
Using a puller, twist them off the axis. It takes a lot of effort here.
Pull the cups out of the glass with a carriage puller. The first is to unscrew the cup from the side opposite to the stars. Then remove the axle.
Remove bearings, inspect and replace damaged parts.
How To Disassemble A Bike
Clean in kerosene, refit and lubricate. When installing, carefully monitor the position: on the one hand, the bearing is placed with balls outward, on the other. inward.
After replacement, cleaning and lubrication, reassemble the carriage in reverse order. After tightening the connecting rods, check their rotation: the lack of effort and cranking indicates that you need to tighten the cups, and vice versa. In these cases, you will have to repeat the disassembly and adjustment.
InStep Pronto child carrying trailer review
Prom bearings are installed immediately, no adjustment required.
“Don’t eat yellow snow”. the mountaineer’s rule
Immediately upon disassembly, we make a defect. Fold the balls in groups of the left-right side. Cones too. It is highly advisable to pour the balls from the same side from which you took them. And tighten with the same cones. Because they have already got used to each other.
If you saw yellow balls from one of the sides (or maybe from all sides), then do not reassure yourself that they are gold, bronze, or, at least, cadmium plated. This says only one thing. On this side, water got under the boot and they got rusty. and this is the main reason to go over the bearings (50:30 is a wild jamb of cheap rear wheel hubs). And if they are rusted, then, most likely, they hooked and knocked the cone. Like mine:
Corrosion has corroded the flare nut on the rear hub bearing, which is why it crunches
New cones are on sale, are inexpensive. If possible, it is better to replace. Otherwise, the balls will be covered, and then the sleeve.
How to disassemble the carriage on a kid’s bike
In pursuit of the lowest cost of production and the highest revenue, many manufacturers neglect some operations. For example, by eliminating overtightening of bushings, carriages, chains (when the wheel, when spinning, makes one revolution, and a lot of effort is needed to rotate the pedals). And if on bicycles for adults, the hub settings are still acceptable, then on children’s bicycles everything is very sad.
If everything on the bike spins easily, then you are very lucky, but we will consider the worst case, when nothing really spins at all.
Taper wrenches 13/14 and 15/16 mm (there are taper wrenches having all these sizes in one).
Wrenches 10, 14, 15, 17 mm (depending on the size of the lock nut. it can be different).
Adjustable wrench up to 32mm range (different sizes of steering nuts on different bikes).
This is how the wheel of a new bicycle spins in our case.
The cone of the front wheel in most cases has a wrench size of 13/14 mm, so take it and a 17 mm wrench (on children’s bicycles, the lock nut can be 15 mm).
While holding the cone, grab the locknut on the other side of the wheel with a wrench, loosen the cone slightly
Re-grasp the loosened locknut with a wrench and tighten it while still holding the bushing taper. If the wheel is still spinning hard, repeat the procedure.
!Important. You need to choose the moment when the wheel spins easily, overtightening is eliminated, but no backlash has formed either.
If there is any play, take another 17mm wrench and tighten the locknuts on both sides with a little effort.
!Don’t overdo it! If you overtighten the locknuts with the cones, there is a risk of extruding the hub cups or leaving noticeable marks on them that prevent rotation.
After revision, the wheel spins longer and easier
The procedure is the same as for the front wheel with minor adjustments.
A flare wrench in most cases is 15/16 mm in size (in some cases it is 17 and 19 mm).
When eliminating overload on the rear hub with a foot brake, loosen the cone only on the right side (where the star is installed).
When eliminating overtightening on the rear hub of a high-speed bike, it will be more convenient to loosen the cone on the left side, because you do not have to remove the sprocket block (if there is a disc brake, especially the CenterLock standard, this recommendation does not apply).
Most bogies on children’s bicycles are collapsible, with 2 cups (one with a retaining ring), a square shaft or wedges, 2 bearings.
Bottom brackets can also be BMX bike designs with large bearings. If you have one, then simply loosen the lock nut 36 on the left side and adjust the tightening torque. Left-hand thread!
Cartridge carriages are a rarity, but if your child’s bike is on a cartridge, you don’t need to fine-tune the carriage.
Using a chisel and a hammer, we unscrew the retaining ring (the thread is right, so we spin it to the left)
Leaning against the groove of the cup with a chisel, we slightly unwind the cup with weak hammer blows. After turning the pedals and making sure that the carriage shaft rotates easily, without the feeling of “staggered” rotation, tighten the lock nut
!Don’t overdo it. If there is a gap, tighten the cup. Otherwise, the bearing will break much faster, and can also leave a depletion on the shaft and carriage cups.
With the chain, the problem is as follows: the rear wheel is simply bolted to the frame with the maximum chain tension, because of this, enormous resistance is formed when pedaling.
Kid’s Bike Repair & Restoration
In the video, the chain is overtightened, it should not be so
Loosen the 17mm nuts securing the wheel to the frame
Unscrew the bolt and nut that secure the brake arm to the frame
Align the wheel so that the chain is not overtightened.
Tighten the nuts on both sides alternately and evenly.
As a result, after tightening the nuts, when you press on the chain, it should give in by about 1 cm
!The stars can be far from ideal, having a significant oval, due to which in one place the chain is overtightened, in another weakened, in the third it is normally tensioned. Choose a moment so that the chain is not overtightened, but also does not fall off the stars when pedaling.
We are talking about the threaded headset, which are most often found on children’s bicycles.
Remove the handlebar by loosening the 12/13 mm bolt (maybe a hex head).
Unscrew the lock nut with an adjustable wrench (can be from 28 to 32 mm in size).
Either with the key, or with your hand, select a moment when the steering wheel rotates freely and has no backlash.
Pedals are a lottery game, and cheap kids’ bikes can have terrible plain bearings. Accordingly, they hardly spin. There is only one way out. to throw them away and buy new ones.
If the pedals have rolling bearings, but they still spin badly, then our article “How to eliminate pedal play” will help you. From it you will understand how to disassemble the pedal and what needs to be done not only to eliminate backlash, but also overtightening.
In addition to eliminating overtightening on children’s bicycles, it is very important to change the lubricant in the rear hub. Structurally, the rear hub with a foot brake is so far from ideal in terms of ease of rotation, and if the manufacturer pulled it over, and even regretted good lubrication for it (which almost always happens), then no pleasure from riding will be obtained.
Therefore, we made an article, after reading which, in the presence of two keys, a screwdriver and lubricant, you can sort out the bushing, change the lubricant and give your child great joy from the ease of riding a bike.
The fact that the carriage has become “buggy” can be found only when you rotate the pedals. Visually, knot problems are difficult to identify, so it is best to prick up your ears and move your attention to the area of the bottom of the frame. You should not listen too much, especially if you are driving on a busy road. However, if the state of the carriage is not good, it will “scream” about itself without delay.
A faulty bottom bracket will prevent you from cycling quickly. Blocked dirt, worn bearings and lack of lubrication will continually impede movement. All this is accompanied by an unpleasant creak and a characteristic knock from below. Also, the unit may start to play (broken bearings and axle misalignment).
You can finally check whether it is really worth disassembling the carriage using the “standing ride” method. To do this, you need to accelerate a little, get up from the seat and twist the pedals. When the carriage mechanism is jammed, the sounds and deterioration of the pedal travel will only increase.
Bicycle bottom bracket: what is it and why?
The carriage is a unit located in the middle of the frame, placed in a special cavity. a glass. Where to looking for? It’s simple: it is hidden where the cranks with pedals and stars are located. The main functions of the carriage are to connect the cranks to the bike frame and provide torque when pedaling.
A quite reasonable question may arise: what, without this device, you can not do at all? There is no bicycle without a carriage. If such a person is still caught, it means that he is not in use now.
Depending on the bike model, carriages differ in size and maintainability. The most common are 68mm knots, but other diameters can also be found. Carriage shaft length range: 110mm, 113mm and 122.5mm.
- cartridge (disposable);
- collapsible to be repaired.
The first type includes carriages that are installed in the frame and cannot be disassembled. Obviously, the service life of such a mechanism is equal to the time of complete wear of the bearings or axle. Full sealing of the unit allows you to operate it for a long time even in extreme conditions, not to mention measured driving.
Collapsible mechanisms will require periodic inspection and maintenance from the owner. The latter consists in replacing worn bearings and lubricating the entire assembly. We will just talk about them further: how to remove the carriage, eliminate the malfunction and reassemble the assembly.
Removing the carriage: doing it right!
It makes perfect sense to first remove the assembly from the bike frame to fix the problem. To be precise, take it out of the glass. Just about how to do it yourself, and the conversation will go.
So, before proceeding with the removal procedure, you will need a set of tools:
- Connecting rod squeeze.
- Wrench. If the size of the nut is unknown, then an adjustable wrench will go.
- Flat screwdriver.
- Small hammer.
- Carriage puller for removing from the glass.
Before proceeding with disassembly, all space around the carriage should be cleaned. A damp cloth removes all dirt and dust from the frame, bottom bracket area and connecting rods. This will be enough so that excess dirt does not get inside during parsing. But it will be better if you wash the whole bike. Cleanliness is the best repair assistant. Proven!
Plugs are removed from the connecting rods. Basically, these are plastic covers that can be easily pry off with a screwdriver and can also be easily inserted back. Next, you need to unscrew the nuts securing the connecting rods to the carriage. A squeeze will help in this matter: we put it on a nut, then we take the key and unscrew it. Depending on the type of thread, the direction of loosening and tightening the nuts may vary. There is an option where the thread is right on the left side (counterclockwise. loosening), and on the right side. left (counterclockwise. tightening). Maybe only right-hand thread on both sides, it will be easy to figure it out.
The next step is to remove the connecting rods. The squeeze is inserted at the other end and twisted into the connecting rod. The squeeze bolt is forcibly screwed into the connecting rod, as a result of which it gradually comes off the axis. It is recommended to start removal from the side where there are no transmission stars.
The bicycle carriage is held in place by means of special cups fixed with rings. A screwdriver is attached to the ring so that its end points to the left. By lightly tapping the hammer on the screwdriver, the ring smoothly turns to the left and jumps off. Similarly, by turning to the left, using the percussion method, the cup is also removed.
So, finally we got to the bottom bracket bearings. These small parts can be removed with the same screwdriver: pry, and they will pop out.
And, finally, a removable device pulls out the carriage shaft from the glass. a rotating part that plays a major role in the mobility of the bicycle cranks.
Troubleshooting: maintenance, cleaning, replacement
Dismantled the carriage, pulled it out of the frame and what do we see? The condition of the bottom bracket depends on how much dirt gets into it and how much the bearings are worn out. Sometimes the bearings simply shatter and require a complete replacement. This often happens if the carriage assembly has been in operation for more than three to five years.
First, all parts must be checked for defects. This primarily applies to bearings. Then we inspect the carriages, cups with latches. If any component has visible damage, then you need to change it to a new one. The rest of the parts are cleaned in a solvent. The most difficult thing will be to clean the bearings: dirt is very firmly adhered between the balls.
The space inside the carriage glass is cleaned with a rag. It is better to sprinkle fine dirt with a lubricating spray (WD-40, for example) and wipe the walls with a soft dry cloth.
How to disassemble and remove the bicycle carriage yourself
Perhaps lovers of simple periodic bike reels are not familiar with this term, but those who often use a bicycle as a vehicle, and even more so, professionals in the field of cycling, are aware of what a bottom bracket mechanism is.
Like any mechanism, this part over time is exposed to external influences, wears out or completely becomes unusable, which requires maintenance, full or partial replacement. In any case, you first need to remove the carriage, establish the suitability of the part, and then decide whether to repair it or replace it with a new one.
Carriage Lubrication and Assembly
Using a screwdriver, the walls of the glass are processed. Apply the product in an even thin layer. No need to put grease inside the mountain. This is useless. Then grease is applied to the bearing, which is inserted from the side of the stars. The flat bezel should face outward. Then you need to lubricate the carriage shaft and insert it so that the long end is on the transmission side. In general, the carriage is assembled in the reverse order.
The bearing on the other side is inserted in reverse, with a frame into the glass. The cups are lubricated from the inside, and then put on. It is necessary to tighten until the axial play is completely eliminated. In this case, the rotation of the shaft should be slightly constrained. As soon as the fastening rings are mounted, the cup will move slightly and the axle will rotate freely.
It remains to collect the connecting rods. The most important thing here is to put them on so that when pedaling, God forbid, they do not fall off. Procedure for Efficient Connecting Rod Assembly:
- The square is lubricated with a small amount of grease, this will help to push it deeper onto the axle.
- Processing a screw with a thread lock.
- Tighten the connecting rod nut with maximum effort until it stops. You can even lengthen the wrench. the thread will not break.
- Insert plugs.
A bicycle is an extremely unstable unit, therefore, during any repair work, it must be carefully fixed. The frame will not wiggle back and forth, which eliminates the risk of the bike falling to your feet or hands.
The carriage is assembled and ready for use. In general, the procedure is simple even for the first time, and in the future it will not be difficult to disassemble and install the mechanism at all.
Carriage assembly repair. A guide on how to repair or service your bike yourself at home.
To disassemble the carriage assembly, you must first remove the crankset with stars. On walking bikes and inexpensive mountain bikes, a conventional carriage assembly is installed:
We unscrew the lock nut on the left side (for the key, see fig.):
We turn off the carriage cup on the left side (key 16):
ATTENTION: On the left side there is a right-hand thread, respectively on the right side there is a left-hand thread.
If necessary, unscrew the cup on the right side (key 32):
Taking out the parts of the carriage assembly. it is recommended to flush and clean the carriage tube, especially the thread.
We wash all the parts (gasoline, kerosene), evaluate the integrity of the bearings, cups and carriage axle. Replace unsuitable parts if necessary.
Next, we do the reverse operations: screw in the cup, on the right side (left thread) until it stops.
We put grease (lithol). We put bearings on the axle and insert it (for the location of the bearings, see the figure above).
We screw in the cup on the left side (right thread), until the rotation of the axis stops, then we turn the cup until the axis starts to rotate without experiencing any, even small, efforts (there should be no backlash).
We check the rotation and absence of backlash of the carriage axis. Repeat steps 9-10 if necessary.