How To Find Out The Size Of The Bottom Bracket On A Bicycle

How to fix a carriage on a bicycle. Removing the carriage from the bike

Next, consider the process of removing the carriages using the example of a Shimano open bottom bracket.

When removing the carriage, you need to be careful, since it can be from bulk bearings, which, when removed, can fly apart in different directions.

To remove the connecting rods from the carriage axis, you need a tool such as a connecting rod squeeze. This tool has two functions: its right side is intended directly for squeezing the connecting rod from the carriage axis, and the connecting rod fixing bolt is removed by means of the left side.

First you need to use a pedal wrench, Unscrew the connecting rod bolts located at the end of the carriage shaft. Plastic plugs (if any) can be easily removed from the bolts with a regular flat-blade screwdriver.

After removing the fixing bolts, proceed to the connecting rods. We take the squeeze of the connecting rods and screw the puller with the threaded part into the connecting rod until it stops. It is very important NOT to overdo it with pressure so as not to break the thread. Having successfully removed the connecting rods from the carriage axis, do not forget to wipe the seats.

Then, using a special puller, we remove the carriage itself. In our case, we are using a Shimano bottom bracket puller. A suitable puller is provided for each individual carriage model. So, for Hollowtech II, Howitzer, GXP carriages, a puller for integrated carriage cups is used, and for Shimano, SRAM and Truvativ carriages, a so-called ISIS standard carriage puller can be used. It should be noted that the set of pullers often includes handles, which eliminates the need to additionally use an adjustable wrench.

It is important to know that the carriage is removed only from the side where there are no stars on the connecting rod, that is, on the left.

So, we insert the puller into the carriage slots on the left side and steep it with a handle or an adjustable wrench counterclockwise. In the process, you need to make sure that there are no distortions of the puller. Otherwise, he or the bowl itself may be damaged.

After the carriage bowl is unscrewed, you need to do the same on the right side. Only in this case you need to turn the handle clockwise! As a result of such simple actions, the carriage will be removed and ready for service or replacement.

Want to see how to remove cranks and bottom bracket? See an overview:

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 the malfunction visually. As a rule, defects lead to the appearance of noise, which 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, a strong backlash appears. This indicates broken bearings and axle misalignment.

Non-separable carriage service

If problems arise with a coach of this type, it is replaced. When choosing a new carriage, it is important to know the length and width of the shaft, as well as the type of connection with the connecting rods.

Carriage Lubrication and Assembly

Lubrication of the mechanism can significantly extend the service life.

You can carry out a similar procedure as follows:

  • The glass wall is processed with a screwdriver.
  • The applied product is applied in an even layer. There is simply a huge amount of lubricants on sale, in most cases, grease or engine oil is used.
  • The next step is to apply grease to the bearing. This unit cannot serve for a long period without lubrication, since rotation becomes a prerequisite for heating and increased wear.
  • Next, the carriage shaft is carefully lubricated. It is a load-bearing element on which there is a high load at the time of operation.

After all the elements have been carefully missed, you need to start assembling.

Recommendations for the work are as follows:

  • The bearing is inserted backwards.
  • The cup is lubricated from the inside.
  • Twisting is carried out until the backlash is completely eliminated. In this case, the rotation of the shaft should be with an interference.
  • Next, the connecting rods are collected. At this stage, you need to be careful, since otherwise the reliability of the fastening decreases.
  • Plugs are being inserted.
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You can assemble it yourself, but you should be careful, since even a slight error leads to a decrease in strength.

Open carriage service:

  • The condition of the bearings in the carriage cup is checked: both the bearings and their seats are wiped with a clean rag from the remnants of old grease.
  • The carriage thread is washed with kerosene, gasoline or WD-40 and wiped off with a dry cloth.
  • The seats are lubricated with a small amount of grease.
  • Bearings are put in, and some more grease is added. If necessary, old bearings must be replaced.

Required tools

You can parse the carriage yourself, but this requires a certain set of tools.

It looks like this:

  • Special squeeze for connecting rod.
  • Keys set.
  • Flat head screwdriver.
  • Light hammer.
  • Special puller for the carriage, which is suitable for removing the glass.

Bicycle carriage maintenance

The bottom bracket is a bicycle bearing assembly that connects the crankset to the frame. Thanks to the bearings inside the carriage, the system can rotate freely. Through the carriage, the torque from the pedals is transmitted to the bicycle wheel.

The carriage is located in the carriage glass of the frame, where it is either screwed in or pressed in. Because the bottom bracket is located at the very bottom of the bike (between the down tube and at the intersection of the bike chainstays), the bottom bracket itself is highly susceptible to dirt. Such a negative external influence over time affects its work: there are “crunching”, clicking, backlash, jamming. To prevent these negative consequences and exclude the possibility of carriage failure, it is necessary to regularly maintain it.

Bicycle carriage repair

Bike bottom bracket problems are familiar to every cyclist. It happens that it loosens up or emits characteristic annoying clicks. This does not always mean that the part needs to be completely replaced. It is enough to competently repair the carriage on a bicycle, and not postponing this matter for later.

Bicycle carriage repair

Bike bottom bracket problems are familiar to every cyclist. It happens that it loosens or emits characteristic annoying clicks. This does not always mean that the part needs to be completely replaced. It is enough to competently repair the carriage on a bicycle, and not postponing this matter for later.

Installing a collapsible bicycle carriage

This type of carriage has a standard device that is well known to all owners of domestic bicycle bikes, which is why it is quite simple to install and configure it.

  • Before starting the installation, rinse the newly purchased carriage and other parts thoroughly in kerosene (it is better not to use gasoline: it is harmful to plastic, oil seals in the cups may suffer). We check if there are small debris and scratches in the frame unit to which the carriage will be attached. If something gets into the bearings from there, the bike will “creak”.
  • We carefully study the ends of the carriage axis (the main thing is not to confuse them!). There must be a special mark on the axle or covers (they are NOT everywhere). There is a special thread in the bowls, thanks to which it is impossible to confuse them.
  • Here you need to place a plastic casing. We put the bearings in the bowls so that the balls are on the inside of the bowls. Cover the bearings and threads on the cups with grease.
  • We begin to collect the case. Sturdy here in that cup, which is on the right side and screw it all the way into the frame mount, using a slotted wrench. Left hand thread on the cup.
  • In the same way we screw in the left cup from the opposite side.

After the installation of the carriage is finished, proceed to the adjustment.

We remove and repair

The carriage can be integrated or non-integrated. The latter, according to the type of device, are divided into cartridge (here, cups, connecting rods. a single system) and collapsible (parts can be unscrewed so that they can be repaired and cleaned). Usually, the carriages of a walking bike or an average mountain bike are arranged in a standard way, so they can be repaired according to the worked out scheme.

To make it more convenient, the bike is better turned upside down and placed on the handlebars.

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After you have made sure that the bike is level and firm, you can start repairing:

  • Carefully remove from the axis first the left, then the right connecting rod.
  • Thoroughly rinse the carriage assembly, Remove old dirt accumulated behind the connecting rods. Very carefully clean the slots in each cup. if they are clogged, it will NOT be possible to install the puller.
  • We proceed to removing the carriage itself. We start on the left (where there are no stars). If your bike has a lock nut, carefully unscrew it with a wrench (you can. family members). Nuts of this type usually have a right-hand thread, so you have to make some effort, but try to tighten the nut carefully so as not to rip the key.
  • After that we take a slotted key or a special key for the carriage. As soon as it enters the grooves, we immediately unscrew the cup with an adjustable wrench with a long handle. If you have a collapsible carriage, the cup must be removed together with the bearing.
  • On the right side (where the asterisks are), doing the same with the same long key. The thread on the cup, respectively, is no longer right, but left, so force is required.
  • Next, you need to remove the right cup with the axis or the cartridge (depending on the type of carriage).
  • If you have a collapsible design, removed from the carriage Removing the bearings. The places where the old grease remains are thoroughly cleaned. Wash all parts in kerosene or any other solvent.

After the carriage is cleaned and the parts are dry, we install in the reverse order.

Adjusting the bearings

Loose bearings are often the cause of extraneous noise, backlash and unpleasant rattling in the rear wheel carriage. This can damage them, deform the cups or impair the clarity of gear changes. If you experience any suspicious symptoms, you need to consider how to tighten the bottom bracket on your bike. In this case, it is better not to postpone the adjustment. If you have the skills, it will be possible to pull up the carriage even during the trip, bypassing the disassembly stage.

How To Find Out The Size Of The Bottom Bracket On A Bicycle
  • Starting work, remove the left connecting rod from the rear carriage and unscrew the lock nut with a special key. Then, using a slotted wrench, slightly loosen the left cup.
  • We twist the left cup almost all the way. It is worth wrapping it loosely or too tightly, as it will start to play or jam. To avoid the latter, slightly (about ¼ turn) loosens the cup with a long key.
  • After that, screw the lock nut from above and tighten it all the way with the same wrench, which was used to unscrew.
  • Checking how the carriages work. To do this, with a steep hand, then. Swing back and forth on the sides. Even a small lift or a barely perceptible jam is a good reason to repeat the adjustment from the beginning.

If you cannot find a balance between play and seizure even after several attempts, you will have to replace either the entire carriage, or worn out or insufficient quality bearings.

What to do if you need to remove the carriage on a bicycle: detailed instructions

If cycling is performed quite rarely, then a person may never be faced with the need to carry out the procedure described in the article. But the regular use of two-wheeled vehicles will sooner or later require appropriate maintenance. Below we will figure out how to remove the carriage from the bike, carry out its further analysis, cleaning and lubrication.

What is a carriage

Bicycle pedals are attached to the cranks, otherwise they are screwed into the carriage. The latter is a shaft placed in a special cavity of the frame. a glass. As you might guess, the element is located at the bottom of the bike. The main purpose of the carriage is to connect the connecting rods and their circular motion during pedaling.

Different carriages are installed on different bike models. They differ in the following parameters:

  • The size. The most widespread are 68 mm knots. However, in a professional environment, you can find shaft lengths of 110 mm, 113 mm and 122.5 mm.
  • Maintainability. Cartridge cartridges are not subject to maintenance; if a squeak or backlash occurs, they are replaced with new ones. Dismountable serviceable: cleaning followed by application of fresh lubricant.
  • Materials. Inexpensive carriages may have a plastic cup on one side that can easily break when disassembled. Below we will indicate the method that will allow avoiding damage to the component during the removal of the part. Also, oil seals play an important role, which protect the bearings from moisture ingress: the better they are, the longer it will NOT require repair.
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Troubleshooting

The features described below will also be relevant for the rear carriage of the bicycle, or rather the hub. The first signal of a problem will be a characteristic sound. A squeak appears when there is insufficient lubrication, and a crunch occurs when dirt gets into the bearings.

The final check is carried out while standing. It is necessary to pick up speed and step on the pedals, if the problem is present, then its symptoms will intensify.

Removing the carriage from a bike

Immediately warn, without a puller, the procedure is almost impossible to perform. If you try to remove without a special tool, there is a high probability of breakage of the carriage cup.

Required tools:

  • Extraction of the connecting rod (if the connecting rod is removed without it, you will need a 14 mm head or an 8 mm hex key);
  • Small adjustable wrench or open-end wrench set;
  • Flat screwdriver;
  • Medium hammer;
  • Carriage puller for unscrewing the glass (depends on the carriage model, manufacturer).

Before starting the procedure, it is recommended to wipe the bike from dirt, so it does not get into the threaded connections. At the end of the preparatory stage, you can proceed to the direct removal of the carriage. Step-by-step instruction:

  • Remove the connecting rod from the sprocket side:
  • Remove the bolted plastic plugs.
  • Unscrew the fixing bolt using a squeegee or a 14 mm head. An 8 mm hexagon is also used depending on the model.
  • Apply squeezes to remove the connecting rod. It is screwed into the internal thread, then the nut is clamped, which moves the pusher.
  • At this stage, the cup and the carriage itself will become visible. They start from the right side, since in some cases a plastic cup is installed on the left side, which easily breaks when twisted. Such a nuisance will require a complete replacement of the carriage on the bicycle. The left connecting rod You can leave it alone. it will be removed by itself at the end of the process.
  • Take a carriage remover and fit it to the cup slots. If the grip is poor, it is recommended to use an M8 bolt as follows:
    • Put some freely moving nuts and a washer on the bolt.
    • Place the puller and fix it in the slots by screwing the bolt into the carriage.
    • When the puller is attached, you can begin to unscrew the cup and the entire carriage. On the right side, this is done clockwise. As soon as the thread gives in to movement, the bolt is unscrewed.
    • The carriage is removed from the landing glass, at the same time the left connecting rod is also dismantled.
    • Further, if necessary, the glass is unscrewed from the left side. A puller is also used for this. There shouldn’t be any difficulties here.
    • Carriage service

      Further disassembly, cleaning and lubrication of the moving parts of the carriage is carried out in the following sequence:

      • The left cup of the score was removed at the time of unscrewing the carriage. The right one remained pressed onto the bushing. To dismantle it, you need to screw the connecting rod bolt into here, then grab the glass with one hand, and with the other, using a hammer, make several blows to the bolt head.
      • Now access to the boot covering the bearings has been gained. They are picked out with an ordinary flat-edged screwdriver. After you managed to remove the boot from the bike carriage, the bearings will become visible. If not, then the access is blocked by the separator. This part is installed when the bearing balls are NOT fastened together. It can also be removed with any sharp object.
    • Next, the old grease is removed with toilet paper, a rag and a brush. It is important to clean all removed parts.
    • New grease is applied to the bearing balls and evenly distributed (e.g. Teflon or Lithol).
    • The separator and the boot are installed in the reverse order.
    • The procedure is repeated for the second party.
    • Apply some grease to the right cup. To press it onto the bushing, screw the connecting rod bolt to the opposite side of the axle, then grab the cup and lightly hit the bolt head with a hammer several times.
    • This completes the carriage service. It remains to install it in the bike frame in reverse order.