DIY bike forward repair

In detail: DIY bike forward repair from a real master for the site my.housecope.com.

Perhaps fans of simple periodic bike rides 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.

The carriage is a unit located in the middle of the frame, placed in a special cavity - a glass. Where to look? It's simple: it is hidden where the cranks with pedals and stars are located. The main function of the bottom bracket is to connect the cranks to the frame of the bike 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 one 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 it to be operated for a long time even in extreme conditions, not to mention measured driving.

Video (click to play).

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, troubleshoot and reassemble the assembly.

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 assembly may begin to play (broken bearings and axle misalignment).

It is possible to 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.

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 with your own hands, 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, you should clean all the space around the carriage.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 there is only a right-hand thread on both sides, it will not be difficult 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.

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: the 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.

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. It's 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 assembly is carried out 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 retaining 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.

A mountain bike, and indeed almost any modern bicycle today is difficult to imagine without a shock absorption system designed to effectively and affordably increase the handling and ride comfort of this type of transport.

Most often, bicycles are equipped with a front suspension fork, thanks to which it is much easier for cyclists to overcome road bumps, even at high speeds, while the load on the palms and hands during the ride is minimal. By minimizing vibration, a well-matched and aligned fork can help extend the life of other bike components such as the frame and steering bearings.

The service life of the fork itself can be extended several times through proper care and regular maintenance.

Often, it is the prophylactic inspection of the fork that makes it possible to timely identify minor deviations from the norm in the operation of the device, and, accordingly, prevent a more serious breakdown. Generally, a visual inspection of the fork includes checking:

dropout states;

fork legs for dents, scuffs and other marks;

oil seals (anthers) for mechanical damage and oil leaks from under them;

pressure in air chambers;

the presence and condition of the lateral backlash of the legs in the "pants";

the condition of the fastening bolts under the “pants” of the fork and the adjustment knobs.

In addition to a routine inspection, the fork also requires regular maintenance, namely:

every 100-150 km of the distance traveled, it is necessary to clean and lubricate the feet on the oil seals;

every 500-1000 km - disassembly and full lubrication of oil seals;

every 4000-5000 km or at least once a year an oil change is made (applies to oil plugs)

In general, a bicycle fork should be lubricated at least once a season, however, if you are actively using your bike, this procedure is recommended to be carried out more often. If we consider a spring-elastomer fork as an example, the lubrication process will look like this:

Using a syringe, oil is poured under the boot.

For the lubricant to be evenly distributed, the fork must be designed.

Any residual oil must be removed with a soft cloth.

According to experts, it is better to use silicone and transparent greases as a lubricant.In addition to lubricating your bike fork, it also includes keeping the device clean. To exclude the possibility of dirt getting into the oil and malfunctioning of the bike, after each walk, you need to wipe the legs of the forks near the anthers.Also, the bike fork can be adjusted by sag or rebound (if available). However, as experts note, this procedure should be performed in stages: after changing each parameter, you should check the progress of the bike. Otherwise, the rider may miss out on the difference in travel, and the effect of fork adjustment will be blurred. It is worth noting that the masters advise starting the adjustment of this device from the neutral position, in which the rebound should be set halfway, and the compression arrows are unscrewed completely counterclockwise.Work on changing the oil, foot oil seals, sealing parts, as well as on eliminating a malfunction of one of the components is accompanied by a complete or partial disassembly of the bicycle fork.First you need to turn the bike with the wheels up, and after releasing the brake (in the case of a rim brake), remove the front wheel.After that, you can remove the stem with the stem and the head tube.Then we remove directly the plug itself. It is important to ensure that the balls are not lost from the bearings when removing the fork. Any sharp object can be used to remove the tapered support ring from the fork stem. After that, you can start repairing or servicing the plug.Next, consider the procedure for disassembling the fork (a spring-electric fork will act as an example):

The lower fixing bolts are unscrewed using the hexagons.

Unscrew the Preload spring force adjustment bolt (it is important to remember the bolt stroke).

An elastomer is obtained, which is entrusted with the function of limiting the travel of the spring (sometimes, if necessary, you can change the size of the elastomer by cutting).

The bolts are unscrewed and the "pants" are taken out. In this case, you need to monitor what flows out of there (dirt, water, oil).

Anthers are taken from the "pants" with a screwdriver, as well as bosses, which for this need to be rotated around their axis.

Further, all components are checked for cracks or other damage and washed with kerosene. Items requiring lubrication are treated with an appropriate material. It is worth noting that it is better to lubricate the spring with a thick grease, which will increase the efficiency of the bicycle fork.

As we can see, a bushing with cup-cone type bearings consists of: body, axle, cups, balls, anthers, flare nuts, washers, anthers, locknuts (and a drum if we consider the rear bushing).

The design of this type of bush is very similar to the previous one, except for the use of industrial bearings instead of loose balls. Because of this, it lacks components such as balls and flare nuts, and the bearing is a one-piece design. The advantages include the ease of assembly and disassembly, as well as the uselessness of adjusting the tightening of the cones. This type of hub can also be used on almost all types of bicycles.

This type of hub is mainly used on single-speed city bikes. Its main feature is the brake, which is installed inside its body and is activated by the movement of the pedals backward. Due to this, it is slightly larger and heavier than its competitors. Below we will give a picture with the design of this sleeve.

Bicycle planetary hubs are very similar to a small gearbox from a car and have a complex design and dense arrangement of parts. Inside this structure, there are many gears, with the help of which gears are shifted. Difficult to repair and maintain. Can often be used on city folding bicycles.

Bushings with a dynamo inside the body are, roughly speaking, a small generator from which you can power various electrical appliances on a bicycle. For example, it can be lighting lanterns. Basically, the dynamo is located inside the front hub of a city or road bike.

Before proceeding to disassembly, let's decide when to service the bicycle hubs. First of all, it should be noted that the service is periodic and forced.

It implies preventive measures for cleaning and lubricating all the hub assemblies of the bicycle in order to avoid their failure, thereby reducing the cost of purchasing new parts and problems with repairs. Many bicycle masters recommend replacing the bushing bearing grease every 5000 km, but as practice shows, a lot depends on the road surface on which you ride and the quality of the bushing itself (the anther design itself). Therefore, the need for maintenance may arise earlier.

If, while riding or checking the rotation of a bicycle wheel, you find backlash, extraneous noise and crackling inside the hub, or there is a difficult rotation of the wheel, then this may indicate several possible reasons:

Incorrect tightening of the tapers (in the case of a taper-cup bearing).
Lack of grease or heavy contamination.
Failure of cups, balls or bushing cone (in the case of a cone-cup bearing).
Failure of industrial bearings (in the case of a slip on a slip).

In this case, the wheel should be repaired and serviced as soon as possible.And what needs to be done for this we will consider below.

We will disassemble and replace the grease using the example of a sleeve with cone-cup bearings.

ATTENTION: When disassembling, clearly note the sequence for removing the bushing components and how they are installed. Also, parts on the left side cannot be installed on the right side and vice versa. The latter is because the balls, cups and cones rub against each other and will not fit well if you move them to the other side.

First, let's disassemble / assemble the front hub of the bike.

Remove the wheel from the bike, remove the eccentric from the hub axle and unscrew the disc brake rotor (if it is naturally present). This is to prevent grease from getting on the brake rotor and to simplify the disassembly procedure.
Remove the anthers on the right and left sides. To do this, carefully pry them with a minus screwdriver.

Next, we'll take a look at how to disassemble and lubricate a bicycle rear hub. In principle, there is not much difference from the method for disassembling the front one (so you can read it first, there are moments that we did not repeat in the description for the back one), except for a few minor differences.

We remove the wheel, eccentric and dismantle the disc brake rotor (if any).
Remove the boot on the left side of the rear bushing with a screwdriver. There is no outer boot on the right side (where the cassette is).

If for any reason you need to remove the cassette, then this can be done literally immediately using a special tool.

Any heavy type of automotive bearing grease can be used to lubricate the bearings in the front and rear bushings of a bicycle. For example, Litol-24 or TsIFTIM-201,158 is a good fit. Of course, no one forbids you to buy specialized bicycle bearing greases, for example, from Shimano, which do an excellent job with their tasks. But to be honest, I did not notice much difference (except for the price).

But what you can not lubricate the bearings of the bushings on a bike: WD-40, motor oils for cars, oils for sewing machines, for lubricating bicycle chains and other liquid lubricants.

When working out its resource or premature breakdown of such parts as: axle, cone, bearing balls, and cups, they are replaced with new ones. And if there are no special problems with the first ones on this list, then with the cups it is not so simple. There are several problems. Firstly, buying new ones specifically for a specific sleeve is unlikely to work (unless you find the same used one). Therefore, you will either need to dance with a tambourine and order a cup from a turner, or look for a donor, knock them out and insert into the victim. Which does not always work out. There is another option. Knock out the cups from the bicycle wheel hub and put the industrial bearings in their place. But here, too, you need to clearly select everything in size and not everything can go as you would like. So if the cups break, you will most likely need to buy a new sleeve.

I would like to note that when replacing balls, you should change everything at once, and not several pieces.

In case of failure of industrial bearings, they also change without problems for new ones.

As for the rest, clean and lubricate the bushings in time, check them for backlash (if necessary, tighten as described above) and the bike bushings will serve you for a very long time.

After reading this article, you learned how to properly disassemble and repair the rear and front bushing of a bicycle with your own hands using the example of pictures and videos. What can be summed up? First of all, maintenance should be carried out periodically and in a timely manner: clean and lubricate, check for backlash and serviceability. In addition, we learned how to lubricate the bushing, and what not, and also learned its structure. Thank you for your attention and good luck with the repair!The bottom bracket is a bicycle assembly that connects the cranks to the frame and allows free rotation.The mechanism is screwed or pressed into the carriage bowl, due to its low position, it is prone to dirt that interferes with normal rotation.Continuous maintenance of the carriage is essential to prevent damage.Carriages are open and closed:Closed - cartridges or capsule designs, with an internal shaft and bearings.The closed model cannot be disassembled and cannot be serviced (with the exception of a few); in case of any breakdown, the part is replaced.The advantage of the model is its low pollution level.The open carriage features screw-in cups with bearings in the carriage tube of the frame and a rotating shaft.This type of mechanism requires accurate frame parameters, in case of inaccuracies, distortions occur and the degree of protection against external influences decreases.The model can be disassembled and cleaned, proper maintenance of the bicycle carriage will prolong the operation of the mechanism for a long time.The disadvantage of open parts is that they require constant maintenance and periodically warp the carriage shaft.It is possible to determine the malfunction of the carriage by too obvious sliding or jamming, squeaks, heavy driving.Knocking and seizing signals indicate damage to the bearing balls or cage. Squeaks can indicate a loose connecting rod wedge. If, while driving, the pedal slips in the upper position, this also indicates a weak wedge tension.A defective part will not allow fast driving, worn bearings, dirt and lack of lubrication will constantly impede movement.The bike assembly begins to loosen gradually due to broken bearing balls and shaft misalignment. To fix it, you need to clean or replace the bracket.Careful maintenance of the bike bottom bracket is imperative before any long ride.A slotted wrench is required to operate the capsule carriage. In working with collapsible mechanisms, you will need a set of tools for different modifications of the part.Carriage Removal Tools:

Squeezing the connecting rods - a functional key for squeezing the connecting rod from the carriage axle and removing the fixing bolt (the right section is for squeezing the connecting rod, the bolt is removed with the left);

Slotted wrenches;

Puller for the mechanism;

Wrench with horns;

Screwdriver.

The tools will also come in handy on long-distance cycling trips.Removal of parts starts from the left-hand area. There is a specific puller for each type of connecting rod. Some modifications are suitable for the puller for the integrated carriage bowl, others can be unscrewed with a standard wrench.Puller kits often include handles for work instead of an adjustable wrench.

At the beginning, fix the bike in a stable position, it is better to turn it over to the seat.

Pull off the pedal arm caps on the pedals with a screwdriver.

Insert the puller into the cavity and unscrew the fixing bolt.

If it does not respond well, you can lubricate the area with any lubricant. With imbus mounts, the appropriate key is selected.Install the puller with the other end into the connecting rod cavity and screw the parts into the thread until it stops.Tighten the tool bolt with a wrench until the connecting rod is pushed out from the shaft side.Free axle, clean with kerosene or WD-40 attachment points.Unscrew the lock washer with a wrench.With a slotted wrench or a puller, the left adapter cup is unscrewed against the clock, in the course - the right one:

The puller is inserted from the left side into the slotted hole of the mechanism and unscrewed with a handle or an adjustable wrench against the clock (to the left);

Do not skew during operation, otherwise the carriage bowl will be damaged;

After unscrewing the bowl, perform the same manipulations on the right side from the other side;

The carriages are removed only on the left side; when removing, take into account that the bearings can fall out of the cavity with an open carriage.

After removing the mechanism, the condition of the bearings in the bowl is diagnosed, all attachment points are wiped with gasoline from dirt:

Damaged parts are replaced with new ones.

The threaded part of the carriage is cleaned with gasoline or WD-40 and wiped with a dry cloth.

The attachment points are smeared with a lubricant.

The bearings are inserted into place and covered with a new layer of grease.

If the capsule carriage is damaged, it must be replaced with a new one. When choosing a model, it is necessary to clarify the parameters of the shaft and the type of connection with the connecting rod levers.The installation of the carriage mechanism occurs inversely to the removal process.During work, it is important not to confuse the axle sections: letters corresponding to the sides are knocked out at the ends or on the plastic casing. The carriage bowls differ from each other in a threaded direction, from left to right and vice versa.The carriage and bowl threads are lubricated with a thin layer of lubricant to ensure sliding during subsequent unscrewing.A plastic casing is attached to the axle, bearings are placed in the bowls: if there are spacers, then the parts are stacked with spacers outward and balls inward.The assembly of the mechanism begins on the right: the axle rod is inserted into the right bowl with a left turn of the thread and screwed into the frame to the end, the left bowl is screwed in the same way with the right turn of the thread.To begin with, remove the left connecting rod arm and lock washer. The left cup is unscrewed with a slotted wrench so that the carriage axis rod rotates freely without backlash and jamming:

The bowl is loosened with a slotted nut wrench by a quarter turn;

While holding the bowl, the lock washer is screwed in until it stops;

Rotation is regulated: the bowl is loosened or tightened;

When the carriage mechanism turns without interference, the connecting rods can be installed.

If, after all the work performed, the carriage jams, replace the bearings or the entire carriage.For more information on carriage maintenance, see the video:

Everyone knows that such bicycles are cheap and, if earlier it was the coolest bike, now they are called "Auchan bikes". Why "Auchan bike"? Because in the Auchan supermarket, they began to sell two-hangers of terrible quality, which soon simply fell on the go. But that's not the point.

There are many types of dual-suspension bike frames - there are even replicas of branded bike frame geometries. And so, the other day, we had the opportunity to cure one two-suspension.

The problem is widespread, which is why it makes sense to talk about it.

Azimut came to us with a single-link suspension (single-pivot). A feature of this type is that when damping, the wheel moves in a circle relative to the main hinge. There are many options for hinge placement. In this frame, the hinge is located behind the carriage.

Advantages of a single-link suspension: simplicity of design, rigidity, can be serviced at home.

Disadvantages: swinging of the pedals, since the carriage is on a triangle that constantly floats, suspension blocking during braking, constant change in chain tension due to suspension travel.

Personal opinion: The usual type of suspension for people who do not need the properties of a super bike. Riding comfortably around the city and in the holes is quite enough. But, ashan, he is ashan.

Owner's opinion: I like the bike for its cheapness, simplicity and the fact that it has a rear shock absorber. It's easy and convenient for me to travel, I don't need anything else to travel on personal matters.

What happened to the suspension and which joint were we fixing?

The problem came out after a few hundred kilometers (which is not strange for Azimuth bicycles) - there was a lateral backlash in the rear triangle, extraneous creaks, knocks, etc.

What have we done to fix the situation?

To begin with, we went through all the small hinges, lubricated them with silicone grease and put them back together. The backlash has decreased by an order of magnitude, but not all. The next step is to disassemble the main hinge, which is located near the carriage.

First, we needed a set of hexagons and a connecting rod puller.

To begin with, the connecting rod clamping bolt was unscrewed with a 14-gauge head with thin walls. Then they inserted the connecting rod puller and unscrewed (squeezed) the connecting rod from the axle. Despite the fact that the bike is relatively new, it was not easy to remove the connecting rods, because at the factory no one thought to give lubricant to the connection between the square of the axle and the connecting rod. Well, okay.

Be sure to unscrew the shock absorber, or at least weaken it. Next, you need to figure out where to support the frame when we unscrew the hinge so that it does not fall.

The next step is to remove the plugs on the hinge, select the necessary hexagons, and begin to unscrew with one hexagon, and with the second hold the sleeve from scrolling. Since the hinge was also not oiled, we had to work hard to unscrew it. We advise you to do this work with a partner.

They promoted and got this:

Look at the photo, there is a clear measure of bushing wear in the joint. Since they were not ready for this, they just greased it thoroughly and clamped the hinge into place. The result is a second week of moderate driving, and the hinge does not squeak and is tightly clamped.

Of course, factory parts do not shine with quality and it is quite logical to replace the hinge bush with a better one. Moreover, this size of the hinge is also used in the frames of famous brands.

What kind of lubricant should I use? We decided to try a silicone-based liquid lubricant, and it has paid off, so far. Time will tell. Why shouldn't you give grease?

Because the gap between the bushing and the frame is small, the thick grease will come out and collect dust on itself. Yes, and we, of course, lubricated the square for the connecting rod so that next time you could disassemble it without any problems.

Video (click to play).

Basically, these bikes require good maintenance, constant replacement, etc. But they are ideal for those who just need a bicycle to get from point "A" to point "B". You should not count on more from such a bike.

Rate the article:

Grade 3.2 who voted: 84