How To Disassemble The Rear Bottom Bracket On A Speed Bike

How to disassemble and assemble a carriage on a bicycle, replacing bearings.

Those who have dealt with used spare parts probably would NOT want to repeat this again. To prevent such unpleasant situations, you just need to process the attachment point before installation.

When replacing connecting rods Apply a small amount of grease to the bottom bracket shaft where it contacts other parts, regardless of type. It is NOT worth putting in too much lubricant, because at the moment of pressing, its excess will be squeezed out of the joint and will remain to collect dirt around it. Before installation, it is also worth lubricating the threads and even some latches.

Radical approach

If the parts are NOT sticky, the previous methods will help you remove the bike crank without a puller. As you can see, the options are quite elegant and, if done correctly, will NOT harm either the bike or you. But it also happens that parts stick very strongly. Especially often at the contact points aluminum / steel or steel / steel.

In this case, a grinder or a drill will help. It is difficult to name a specific method of cutting, since the design of frames and systems can be very diverse. On some bicycles, you can simply cut off the bottom bracket, on some you can try to drill the largest possible hole in the place of the thread, which, under the influence of vibrations, will help to destroy the connection or break the metal.

A bonded joint can be destroyed by temperature extremes. Heat the connecting rod head, for example with a burner, and then cool it down as hard as possible. Due to the physical properties of metal, there is a chance to remove the bicycle cranks without a puller as soon as the structure cools down.

You can experiment by combining the above methods, or try your own unique.

Puller Features

Before you know how to remove the carriage from a mountain bike, you need to learn about the puller tool. It must be selected taking into account the appearance and structure of the carriage itself. Often the carriage manufacturer must match the puller manufacturer. Today, there are universal types of puller in the world, but, unfortunately, they may not fit this or that mechanism. This mechanism is excellent for removing so-called carriage cups. This is precisely the main feature of the mechanism. Therefore, when using such a device, you should be extremely careful and attentive.

And how to remove the carriage from a bicycle without a puller?

How to disassemble and remove the bicycle carriage yourself

Perhaps lovers 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 even 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.

How to remove connecting rods from a bike without a puller

Active cycling requires certain skills to quickly repair vehicles. Before setting off on a long trip, it is best to foresee possible breakdowns and malfunctions of equipment, take with you the necessary tools and a set of spare parts, for example, cameras. It often happens that the right thing was not at hand, but even then there is a way out of the situation. For example, if you need to adjust the carriage of a bicycle, then you need to remove and disassemble the connecting rod, and there is a tool. This problem has a solution and is worth getting acquainted with the design and purpose of this part in more detail.

Convenient instructions for removing this carriage

A lot of people are wondering how to remove the bottom bracket from a bicycle without a puller. The question is quite interesting, but first let’s look at the instructions for the standard process. It is important to remember that the design of this product contains small bearings, which often crumble. Therefore, you need to understand that it is necessary to carry out the removal and repair with accuracy and care.

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. It is not worth listening too much, especially if you are driving on a busy road. However, if the state of the carriage is not good, it will “scream” 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 backlash (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.

If there’s nowhere to rush

Let’s say you bought new cranks and want to replace them, but the old ones can still last a few days. In this case, you can try the following method:

  • Unscrew the carriage fixing bolts.
  • Spray any penetrating grease into the contact area.
  • Go cycling, not screwing in bolts.
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There is a chance that frequent vibrations will cause the connecting rods to come off the shaft. Be careful, if they fly off during the jump, it will be extremely unpleasant.

The Hollowtech II standard is the least problematic. In order to remove the connecting rods, you only need a 5 mm hexagon, a special wrench for this standard, which is easily replaced with a 10-11 mm hexagon, and a little effort if the system is stuck to the bearings. Even a child can cope with this.

Device and purpose of the part

The connecting rod for bicycle equipment is a metal lever, which has a large and small head on the rod. This element is of several types:

  • One-component. They represent a single structure. left, right connecting rod, here. The advantages of this type are great strength, easy maintenance, but they have a significant weight;
  • Two-component. Here the driving sprocket, the right connecting rod and here are connected, and the left one is connected separately with a nut;
  • Three-part. This most famous and popular system is, here, the left and right connecting rod together with a star.

The load on the connecting rod is very high, and therefore they are most often made from solid steel, but there are also options from aluminum alloys, for example, in sports type bicycles or imported models. Inexpensive two-wheeled vehicles have a front sprocket, combined with a connecting rod and non-separable. In this case, when replacing the sprockets, both connecting rods must be replaced. New ones are selected depending on the type of existing carriage.

This part of the bicycle can also have various types of fastening, for example, square, slot. The first is used in professional sports models of equipment, and there is also the latest development. a rotary system.

Assembling and Installing the 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 cup has a left-hand thread.

It is worth starting to assemble the carriage from the right side: the carriage 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 it in different directions and make sure that 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.

Screwing the mechanism off the frame

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:

  • Connecting rod squeezing. a functional key for squeezing the connecting rod from the carriage axle and removing the fixing bolt (right section for squeezing the connecting rod, the bolt is removed with the left)
  • Slotted wrenches;
  • Puller for the mechanism;
  • Wrench with horns;
  • Screwdriver.

The tools also come in handy for long distance cycling.

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.

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 thread, and the left one has a right 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 carriages into the right cup and twist the carriage with a 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 spin easily and silently). For this, the carriages are steep 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.

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.

Preventing corrosion

Those who have dealt with used spare parts probably would NOT want to repeat this again. To prevent such unpleasant situations, you just need to process the attachment point before installation.

When replacing connecting rods Apply a small amount of grease to the bottom bracket shaft where it contacts other parts, regardless of type. It is NOT worth putting in too much lubricant, because at the moment of pressing, its excess will be squeezed out of the joint and will remain to collect dirt around it. Before installation, it is also worth lubricating the threads and even some latches.

A red stealth class fell into our hands with AKVO “ashanbike” diagnosed with carriage play. It was decided to disassemble the carriage in order to change the lubricant and subsequent adjustment. The whole process took several hours and was accompanied by the Adoption of such original technical solutions (as tools were used: an electric kettle, two wooden blocks, Mighty pressures, half a meter long armature and an ax, and I do not even mention in a standard tool such as wrenches and pullers) that in the middle of the process I ran for the camera and then documented everything.

The first step was to unscrew the nuts securing the connecting rods to the axle. Please note that the nuts, not the bolts. The first bummer befell us when the puller was screwed into the connecting rod. The puller is designed for here with holes for bolts, but on this miracle of Chinese horseradish construction, it ended with studs threaded for nuts, which prevented the puller from being screwed in.
(Despite the fact that Stealth is a Russian brand, the closer we got to know the device of this carriage, the less doubts remained about its origin not just from China, but from the most depressed and agrarian Chinese region).
Attempts to knock down the connecting rod with a hammer through a wooden spacer were NOT successful. But, fortunately, the connecting rods were aluminum, but steel, and the thought of the difference in the coefficients of thermal expansion of THESE two materials simply could not pass us by. After sprinkling the junction with boiling water from a kettle, the connecting rod was knocked down without much difficulty.
After removing the left connecting rod, access to the carriage cup was opened. It is not very visible in the picture, but the slots on the cup are so deep that they are divided in two by the hole under the here and it is impossible to grab them with an ordinary wrench. Fortunately, a rare adjustable wrench with flat jaws was found in the bins.

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General view of the battlefield

After unscrewing the cup, a rusty cage with balls was found inside. When trying to pick it out with a screwdriver, it crumbled, and the balls rolled across the floor. The balls that we caught up had a shape close to a cube or tetrahedron. It became clear that a simple replacement of the lubricant would NOT end.

Removing the right connecting rod seemed to be an easier task. the bike was hoisted on a stand of two logs, the seat was poured with boiling water

And then knock out with a long rod, because On the left side, nothing held her.

True, it was possible to knock out only after the second kettle of boiling water and the use of WD-40.

The second cup of the carriage was opened to our eyes.
It became clear that the Gloomy Chinese genius created this carriage with one purpose. to make fun of the topic of who will take it off, because its main function. it turns. at the time of the start of the repair, the carriage was practically NOT performed. On the right cup, the slots were the complete opposite of their neighbors on the left. barely noticeable, and created as if by a gentle touch of the file.

The use of a wonderful adjustable wrench did not bring such results as last time. his lips with broken edges jumped off tiny splines when trying to turn.
There were applications of the principle of Magomed and mountains. If you can’t spin the cup of the bike, let’s spin the bike around the cup. I managed to grab the cup in a vice, which gave significantly more compression force than the key. However, the cup still turned out of them. We change the starting point back. the bike is at the bottom, the pressure at the top. theirs and steep.

At the cost of an incredible tension in the centers of the brain responsible for the formulation of multi-storey speech structures, the cup was returned by a quarter of a turn. The problem was not centuries in the severity of rotation, but in the uncomfortable position of the vice, which jumped off at the slightest distortion. However, the main thing was done, and turning the cup with an adjustable wrench (processed with a sharpener for better girth of the slots) was a matter of technique.

The new VP cartridge carriage was screwed in in a minute using a special puller.

I’m sure she will survive this frame.

Overall, this bike isn’t nearly as bad. It has a rigid (non-shock absorbing) fork and even more so there is no rear shock absorber (although the shape of the frame from afar hints at its presence). The exotic shape of the frame only makes the bike heavier, but does not prevent it from driving (although it does not have to be said in the NAC). The carriage was the most unreliable unit it led, and after its replacement, as well as the planned replacement of brake and switch cables and shirts, chains and a 6-speed cassette, it will serve for more than one year.

Diagnostics of breakdowns or contamination

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 the pedal slips in the upper position when driving, 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, you need to clean or replace the bracket.

Careful maintenance of the bike bottom bracket is a must before any long ride.

A little about standards

On bicycles of different classes, it is logical to install bicycle cranks and carriages of different standards. The following types of carriage assembly are currently popular:

  • Standard square mount. the old look for budget bikes.
  • Octalink, designed by Shimano. It has several subspecies, including standards of second manufacturers that are very similar in design. In fact, it is a kind of “square” carriages, but has a redesigned shaft and modified splines.
  • Hallowtech II is considered the best option in terms of stiffness / weight ratio, but it costs more than others. Also invented by Shimano.

On older bicycles, wedges were a common mount. There were quite a few problems with such a system, which is why it remained in the last century. Now they are practically NOT produced, and even the most budgetary bicycles are equipped with carriages with a square shaft.

Radical approach

If the parts are NOT sticky, the previous methods will help you remove the bike crank without a puller. As you can see, the options are quite elegant and, if done correctly, will NOT harm either the bike or you. But it also happens that parts stick very strongly. Especially often at the contact points aluminum / steel or steel / steel.

READ  How to Shift Sprockets on a Bicycle

In this case, a grinder or a drill will help. It is difficult to name a specific method of cutting, since the design of frames and systems can be very diverse. On some bicycles, you can simply cut off the bottom bracket, on some you can try to drill the largest possible hole in the place of the thread, which, under the influence of vibrations, will help to destroy the connection or break the metal.

A bonded joint can be destroyed by temperature extremes. Heat the connecting rod head, for example with a burner, and then cool it down as hard as possible. Due to the physical properties of metal, there is a chance to remove the bicycle cranks without a puller as soon as the structure cools down.

You can experiment by combining the above methods, or try your own unique.

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 from 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.

How To Disassemble The Rear Bottom Bracket On A Speed Bike

Connecting rod fixing nut.

After removing the fixing bolts, using the squeezing of the connecting rods, we tighten 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. Besides 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 Spline 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, i.e. 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 use an adjustable wrench cool counterclockwise. 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.

Shimano bottom bracket puller.

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 bike.

Howitzer Carriage Puller.

ISIS carriage puller.

If you have an integrated carriage, then you can change the industrial bearings by replacing the speeches. 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 with a hammer and chisel (not recommended). Clean and grease the seat, after which we install new industrial bearings.

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

Carriage repairs may include:

  • Routine Carriage Maintenance (Lubrication and Bulkhead)
  • Eliminate the backlash of the carriage;
  • Tight rotation of the carriage axis;
  • Extraneous sounds in the area of ​​the carriage assembly.

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 mentioned in the previous article, a bicycle bottom bracket is a bearing assembly that connects the crankset to the frame and provides a torque function for the bike crankset. 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. Due to the fact that the carriage is located at the very bottom of the bike and when using the bike throughout all seasons of the year, it is often subject to external influences, i.e. the ingress of saws, dirt, moisture, etc. there was a “crunching”, 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 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 (axle), which rotates with the help of bearings, which are installed in the carriage cups and screwed directly into the carriage glass 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.

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 thread, and the left one has a right 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 carriages into the right cup and twist the carriage with a 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 spin easily and silently). For this, the carriages are steep 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.