How to properly assemble the rear bottom bracket on a bicycle

Integrated carriages

properly, assemble, rear, bottom

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
  • Hope
  • RaceFace X-Type
  • Token
  • Chris king
  • FSA Mega Exo
  • Compatible with SRAM, Truvativ, Bontrager:
  • GXP (GigaX Pipe)
  • Hope (via proprietary adapter)
  • Chris King (via proprietary adapter)
  • Campagnolo ultra-torque.
  • Adjusting the split carriage bearings

    After assembly, the carriage must be adjusted, but often it is necessary to adjust without disassembly. For example, sometimes after a long drive on uneven roads, a play appears in the carriage, which should be eliminated by adjusting. Backlash in the bottom bracket can, at best, lead to poor shifting accuracy and, at worst, damage to bearings and cups. On a long trip, you can try to adjust the carriage without disassembling.

    Before starting the adjustment, it is necessary to remove only one left connecting rod, remove the lock nut (with a special wrench) and slightly loosen the left cup (with a slotted wrench). The nut and the left cup have a right hand thread. 1. We turn the left cup almost to the stop so that the carriage axis rotates easily, without jamming, and at the same time has no backlash. Then we loosen it with a slotted wrench by about a quarter of a turn. Screw on the lock nut while holding the cup with a slotted wrench. We tighten the nut special. key all the way.

    Now you need to turn the axis of the carriage by hand, and shake it from side to side. If everything is done correctly, then the carriage should rotate freely, without jamming, and not have a noticeable backlash. If it sticks or there is a backlash, then unscrew the lock nut, and repeat step 1, loosening or tightening the cup with a spline wrench.

    When the carriage rotates without jamming and backlash, you can put the connecting rods.

    Sometimes the carriage cannot be adjusted. That is, when you try to make it rotate freely, then there is a backlash. And vice versa, if you eliminate the backlash, then the axis rotates tightly, with jamming. This suggests that it is time to change either the bearings or the carriage itself.

    Eccentric carriage

    Allows the use of a drive without external gear shifting (singlespeed, planetary hub) in combination with conventional vertical frame dropouts. These dropouts provide a faster and more comfortable wheel positioning compared to horizontal ones. The eccentric carriage is rotated in its seat, allowing the chain to be tensioned, then fixed with bolts and / or union nut. On serial bicycles, such carriages are rare, one of the most common examples is the Strida. Also usually installed on tandems as a front carriage, which makes it possible to tighten the timing chain.

    Varieties:

    • 54mm standard. for example, Bushnell Eccentric Bottom Bracket. Has a BSA thread for a standard BB, requires a special frame with a 54 mm seat.
    • Standard 46mm. Fits into a standard Press Fit 30 frame. Integrated system (24mm axle) fits directly into the carriage.
    • BSA Standard. Fits into a standard BSA threaded frame. The integrated system (with a 24 mm axis) fits directly into the carriage. Provides chain length adjustment only within 1/2 link, requires use in conjunction with a half-link chain.

    On http://www.bike-repair.ru it is told in great detail about the repair of carriages and how and how they can be removed. Let’s figure it out with this issue too.

    Press-fit

    Recently, integrated systems such as BB30 / Press-fit are gaining popularity. The design feature is that the bearings are pressed directly into the frame (plastic cups can be used), an aluminum axle with a diameter of 30 mm is threaded through them (instead of a steel one with a diameter of 24 mm). This promises a further increase in the rigidity of the knot with some weight reduction. On the other hand, bearing replacement tools are significantly more expensive than conventional carriage pullers.

    Classic Press fit for BB30 30mm axle systems:

    How to Build a Bike. Part 2 of 12: Bottom Bracket, Crankset & Pedals

    • BB30: cup inner diameter 42mm, cup width 68mm for highway or 73mm for MTB, bearings without cups.
    • Press fit 30 (PF30): cup inner diameter 46 mm, cup width 68 mm for highway or 73 mm for MTB, bearings with cups.
    • Press-fit carriages for standard systems with 24mm steel axle:
    • BB90 / 95: cup inner diameter 37 mm, cup width 90.5 or 95.5 mm, bearings without cups.
    • BB86 / 92: cup inner diameter 41 mm, cup width 86.5 or 91.5 mm, bearings with cups.
    • Unique standards requiring their own 30 mm axis system:
    • BBright Direct Fit: cup inner diameter 42 mm, cup width 79 mm, bearings without cups.
    • BBright Press Fit: Cup Inner Diameter 46mm, Cup Width 79mm, Bearings With Cups.
    • 386 EVO: bowl inner diameter 46 mm, bowl width 86.5 mm, bearings with cups.

    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.

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    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.

    Fault definition

    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.

    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.

    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.

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    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.

    How to troubleshoot

    The machine will last longer if it is properly cared for. The carriage is replaced for various reasons:

    • seasonal maintenance consisting of cleaning, lubrication, bulkhead;
    • elimination of backlash;
    • tight turning of the axis;
    • jamming of the mechanism;
    • the appearance of extraneous sounds in the pedals when the device is operating.

    The first warning signs of damage to the rear carriage are characteristic sounds. A squeak occurs when there is insufficient lubrication, a crunch occurs when dirt gets into the bearings. In the presence of such features, the mechanism is analyzed.

    It is impossible to visually determine the malfunction; problems appear only while driving. Even minor breakdowns do not allow full acceleration, cause difficulties when turning the pedals. Repair of the bicycle carriage will be required if there are backlashes, which indicate bearing wear, axle misalignment.

    In some cases, the “standing ride” method is used to diagnose problems. To do this, you need to gain high speed, then stand up, leaning on the pedals. If there is a loud cracking noise, noise, the bicycle carriage will have to be replaced or repaired.

    How to properly remove the carriage from the bike and put it back

    Active riding on two-wheeled vehicles requires initial skills for quick repairs. When packing for a long trip, you need to think over possible breakdowns, take with you the necessary set of tools. Many athletes are interested in how to remove the carriage from a bicycle with their own hands to adjust, restore the element. Thanks to the detailed description, you can figure out how to maintain the mechanism, eliminate breakdowns, and carry out assembly.

    How to identify a faulty carriage?

    It is possible to determine that the carriage is faulty only when pedaling.

    Among the features, we note:

    • It is almost impossible to determine a malfunction visually. As a rule, defects lead to the appearance of noise that is heard when driving.
    • Even a minor defect will not allow moving at high speed. In this case, even dirt or lack of lubrication leads to difficulty in movement.
    • In some cases, there is a strong backlash. This indicates broken bearings and axle misalignment.

    Procedure

    Such a set is not always found in a cyclist’s set, so you will have to purchase some tools separately.

    The procedure is as follows:

    • Free up space around the carriage before replacing the carriage.
    • Remove dirt with a soft cloth. This is done so that dirt does not get inside the structure during parsing.
    • The plug is removed from the connecting rod. In most cases, a plastic cover is used as a plug, which is enough to touch with a screwdriver.
    • The next step is to unscrew the nut, which secures the connecting rod to the carriage.
    • Next, a special squeeze is applied, for which it is put on the fastening element.
    • The next step is to remove the connecting rod. For this, a special release tool is also used. As a result of applying force, the knot gradually leaves its place.
    • It should be borne in mind that the carriage is fixed by a special cup and rings. With light movements and blows, the rings rotate in the seat. Similar actions are taken to remove the cup.
    • The carriage bearing can be removed with a regular screwdriver, for which light blows are carried out.
    • A special removable tool is used to pull out the carriage shaft. It is almost impossible to dismantle with a conventional tool.

    Assembling and installing a bicycle carriage

    An important point when assembling the carriage is that the cups are correctly positioned. It is worth remembering that the left cup has a right-hand thread, and the right one has a left-hand thread.

    GXP Bottom Bracket Install. Do You Need To Use Spacers?

    It is worth starting to assemble the carriage from the right side: the carriage axle is installed in the right cup and twisted by the carriage puller until it stops. Then the same is done with the left cup. After that, it is recommended to check the carriage: you need to twist its axis in different directions and make sure there is no backlash (the carriage should turn easily and silently).

    At the end of the process, the connecting rods are installed in their places and fixed with screws.

    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.

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    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.

    Part assignment

    The carriage of a bicycle is a shaft that fits into the cavity of the frame. a glass. The connecting rods are attached to this element, and the pedals are fixed on them. The part is located at the bottom of the structure. The mechanism consists of a body, a cup, a bottom bracket and an axis rotating on bearings.

    Ball bearing carriage lubrication

    It should be noted that carriages of this type are short-lived, so maintenance and adjustment of bearings should be carried out quite often.

    How to Remove and Install Bottom Brackets. Threaded Shell (BSA, T47, Cartridge, etc.)

    Bicycle carriage repair (maintenance)

    You will need a tool to remove the carriage.

    A bicycle, like any other type of movement, requires maintenance, which can be performed both in specialized workshops and at home using a special tool. Today we will talk about the repair (maintenance) of the carriage, which includes disassembly, lubrication, installation and adjustment of the bike carriage.

    As discussed in the previous article, a bicycle bottom bracket is a bearing assembly that connects the crankset to the frame and provides a torque function to the crankset on a bicycle. The carriage is located in the bottom bracket of the frame, which is located between the down tube and at the intersection of the chain stays. Because the bottom bracket is located at the very bottom of the bike and when the bike is in use throughout all seasons of the year, it is often exposed to external influences such as saws, dirt, moisture, etc. Over time, in the area of ​​the bottom bracket “crunching” may occur, backlash, clicking and the carriage begins to go out of its usual work. the smoothness and accuracy of work decreases, sometimes even jamming may occur. All of this can be corrected with carriage maintenance.

    Closed-type carriages (cartridge) cannot be repaired, therefore, if problems arise with this type of carriage, it simply changes to a new one. But the carriages of an open type (collapsible) lend themselves to maintenance, since they are a shaft (axis) that rotates with the help of bearings that are installed in the carriage cups and screw directly into the carriage cup of the bicycle frame. Therefore, they can be easily removed, lubricated, replaced bearings and reassembled, or simply replace the old carriage with a new one.

    Removing the carriage from the bike and maintaining it

    In this article, we will cover the maintenance of Shimano open bottom bogies. The carriage can be with loose bearings, so be careful when removing, as the balls can scatter in different directions, as well as in the form of a non-separable cartridge.

    After removing the fixing bolts, using the squeezing of the connecting rods, we screw the puller with the threaded part into the connecting rod until it stops, but here you need to tighten it progressively and without much effort so as not to break the thread. We remove the connecting rod from the carriage axis and wipe the seats. After removing the connecting rods from the carriage shaft, you need to remove the carriage itself, for this you need a shimano carriage puller.

    If you have a different carriage type, you will need other carriage pullers. In addition to the puller for shiamno, there is also a puller for integrated carriage cups and is suitable for HOLLOWTECH II, GXP, Howitzer. Another ISIS Bottom Bracket Puller with 8 Splined Puller Mount and is suitable for Shimano, Truvativ and SRAM. All types of pullers can also be equipped with handles, and you do not need an adjustable wrench.

    When unscrewing the carriage, it must be remembered that the carriage must be removed from the left side, that is, from the side where there are no stars on the connecting rod. We take a puller, insert it into the carriage slots on the left side and turn it counterclockwise with an adjustable wrench. It is very important to avoid any distortions of the stripper when unscrewing the carriage cups, so as not to damage the cup itself and the stripper.

    After the carriage has been removed, it is necessary to check the carriage cup for dirt, sand and other things that could get there, both through the carriage and the seat tube of the bicycle.

    If you have an integrated carriage, then you can change the bearings by replacing the seals. To check the condition of the industrial bearings, remove the boot and see the old bearings. They can be removed with a special puller for internal bearings or disposed of with a hammer and chisel (not recommended). We clean and lubricate the seat, after which we put new industrial bearings.

    Before installing the carriage, wipe and lubricate all threaded connections.

    Carriage repairs may include:

    • scheduled carriage maintenance (lubrication and bulkhead);
    • elimination of backlash of the carriage;
    • tight rotation of the carriage axis;
    • extraneous sounds in the area of ​​the carriage assembly.

    Bicycle bottom bracket installation

    When assembling the carriage, the main thing is to place the cups correctly. Let me remind you that they have different threads, namely. the right cup has a left-hand thread, and the left one has a right-hand thread. Before installing the carriage, grease the carriage cup, bearings and cup threads with grease. The assembly of the carriage must be started from the right side. To begin with, we insert the carriage axis into the right cup and twist it with a carriage puller, and then the left one until it stops. After the carriage cups have been screwed in, it is necessary to check the carriage for any backlash (the carriage should rotate easily and silently). To do this, we twist the carriage axis in different directions. Be careful and make sure that the cup runs smoothly along the thread, as it is very easy to damage it. We put in place the connecting rods and fixing screws.