Bicycle gear shifting broke

What to do if your bike’s derailleur is broken

There is no special science in shifting gears on a bicycle; at first glance, everything is simple. Two levers on the left, two on the right, or even just a grip-shift. what could be easier. But nevertheless, observing novice cyclists, one may notice not entirely correct and coordinated actions. But consistency when cycling is the most important thing! This is the only way you will be able to move as efficiently as possible on a bicycle, make maneuvers, overcome obstacles.

bicycle, gear, shifting, broke

As an example, we will consider the most ordinary mountain bike (MTB) with three stars in front and 8-9 in the back.

Before you start adjusting the front derailleur

Before you start adjusting the front derailleur, make sure you have the following conditions:

We start by unscrewing (loosening) the bolt that holds the front derailleur cable.

Next, I recommend checking the position of the switch frame relative to the star system.

If your switch is bolted to the frame, and not with a clamp, as in my case, then you do not need to set the height and angle of the switch, since everything is already exhibited there.

A. Check the angle of rotation. The switch frame must be parallel to the stars of the system.

B. Check the height. The front derailleur frame should be slightly higher by 1-3 mm. than the largest star in the system. To adjust, slide the frame by hand so that it is above the 3rd star and adjust the height.

Most often, new shimano front derailleurs have a sticker that shows how high the derailleur should be.

Now let’s start working with the cable and shifter on the handlebars.

A. Find the cable tension bolt on the shifter and screw it all the way into the shifter and turn it half a turn.

B. Pull the cable by hand or use pliers and tighten it with the fixing bolt, which I wrote about in paragraph 1. Note that there are special grooves on the washers holding the cable. It is necessary to fix the cable in them.

We begin to set the extreme positions of the switch frame with bolts H and L.

High. sets the extreme position at the largest star in the system.

Low. adjusts the extreme position of the switch on the smallest star.

We expose the extreme position of the frame using the bolt L

To adjust the extreme position of bolt L, you need to switch to the largest sprocket on the rear derailleur (corresponds to the first speed on the shifter). Next, we begin to twist the bolt L until there is a gap of about 1 mm between the chain (which is located on the smallest star of the system) and the switch frame (the smaller the better, the main thing is that the chain does not rub against the switch frame).

We expose the extreme position of the frame using the bolt H

When setting the end position H, we need to switch to the smallest star on the cassette, which corresponds to the largest number on the right shifter from 6 to 11, depending on how many speeds you have there. We throw the chain onto the third star (the largest star on the system) and turn the screw H. Adjust the frame so that the chain does not fly onto the connecting rod with a clearance pedal of 1 mm will be quite enough.

Checking the clarity of gear shifting.

Try to change gears and see if the chain goes to all stars.

often than not, the chain does not go from the second star to the first and clings to the switch frame. This is solved by unscrewing the bolt L (so that the switch frame moves towards the frame) one or two turns and everything should work perfectly.

Let’s immediately highlight the most common errors and problems:

  • Too heavy gear is a common mistake. Many newbies even say that 44 (or even 48) stars in the front are not enough for them. It’s a delusion. Constantly spinning a heavy gear you are simply killing your knees. Try to keep track of your cadence (cadence) until it becomes automatic. You can even count the number of revolutions per minute for the sake of interest. If it is around 90-100, then this is very good. And so, gear 44-11 is enough to accelerate on the plain to

60 km / h So try to convince those who say that 44 stars are not enough for the city. By doing this, you may help to keep people healthy

  • Curve transmission. it is not uncommon to observe how people, without looking at the chain, include gears like 3-1.2. In this case, the chain goes to bend, its wear increases, at the wrong moment it can simply fly off. The optimum chain position is when it passes from the chainring to the rear with minimal skew. So be sure not only to make it easy to twist, but also the position of the chain.
  • Switching under load. so even fragile girls manage to break chains, what to say about healthy men. And what a crunch at the same time. When shifting, reduce the load on the pedals to a minimum, just rotate them with ease until the chain jumps to the desired sprocket. Therefore, it always makes sense to assess the situation, possible obstacles and change gear in advance.
  • Chain biting is when the chain is pulled up by the chainrings when shifting. An unpleasant situation in which the nib near the carriage assembly may be severely scratched. This could be due to cogging on the star, dirt, improper assembly and setup. This is another plus to why you need to watch the shift, and not just mindlessly flip the shifters. All movements should be smooth, even airy.
  • Chain skipping. for example, you put a new chain on an already similar cassette (by the way, the chain resource
  • 1500 km). As a consequence, when the load on the pedals increases, the chain slips and the pedals fail unpleasantly. This must be taken into account and travel more carefully until everything gets used to it. Even for a fairly strong cassette, the rubbing period is about 200 kilometers.

    If you are new to the saddle, pay a lot of attention to pedaling, shifting, try to work with both the front and rear derailleurs. Try to choose a gear depending on the maneuver being made. For example: you slow down, but you will need to accelerate for this. Shift the gear lighter even when braking, then it will accelerate faster.

    The clarity of gear shifting is highly dependent on the technical condition of the bike components. Monitor and, if necessary, replace the cables and shirts in time, the rear derailleur rollers, the switches themselves, the drive elements. the chain, cassette, front sprockets.

    I strongly recommend that you set up the rear derailleur before you start setting / adjusting the front derailleur so that everything works correctly for you. This manual will fit all brands and models of front derailleurs: Shimano, Sram, Microshift, Campagnolo and others.

    • Prerequisites for Configuring a Switch
    • Unscrew the bolt
    • Checking the position of the switch frame
    • Working with a cable and a shifter
    • We expose the extreme position of the frame
    • Checking the clarity of switching
    • Differences between road derailleur setting and MTB
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    Set the center position of the front derailleur frame

    It is necessary to transfer the chain to the center sprockets of the cassette using the rear derailleur. We switch from the first to the second speed (the chain should initially be on the 1st star), if it does not switch, then it is necessary to tighten the cable with the tension regulator (see paragraph 3.A), which is located on the shifter. We twist until the chain clearly and quickly transitions to the middle star.

    Differences between road derailleur setting and MTB

    There is no difference in front derailleur settings on mountain bikes and road bikes. The only thing is that in a road bike, the star system does not use 3 stars, but two stars, which makes the tuning faster.

    If you have a dual system. You will also need to complete all the points, and in the 4th step there will be no adjustment of the central position, and the tension of the cable will be adjusted when switching to the 2nd star, where there will be an adjustment of the extreme position with the screw H.

    The conveyor device and the reasons for its functional failures

    Before adjusting the rear derailleur on a bicycle, it is useful to find out the reasons for the malfunctioning of the mechanism. The essence of the problem lies in the following points:

    • Cable damage or lack of lubricant.
    • Violation of the integrity of the cable jacket.
    • Curved cock. fastening the mechanism to the bike frame.
    • Worn chain or sprocket cassette.
    • Jammed chain tensioner rollers.
    • Steering wheel gear shift problems.

    Shimano Mountain Bike Rear Derailleur Adjustment Screws: Technical Minimum

    Despite the variety of parallelogram-type spreaders from the Japanese manufacturer, their design and principle of operation are similar. In the process of adjusting the device, five elements are involved:

    • 1. fastening the cable in the form of an embedded bolt with a nut.
    • 2. screw for tensioning the cable with a drum.
    • 3. a screw for adjusting the chain tension.
    • L. limit screw for adjusting low gears.
    • H. limit screw for correcting high gears.

    Special screws L and H, which are used to adjust the rear derailleur of a bike with Shimano Alivio, physically restrict the movement of the mechanism, which prevents the chain from jumping off. In practice, they are used mainly only when debugging a new transfer device, subsequently the procedure is not needed.

    In the event that the cock or the mechanism itself is bent, adjusting the stop screws can solve the problem for a short time. Their sensitivity is not very high, so 1-2 turns at a time are quite justified.

    Technique: how to properly adjust the rear derailleur on a bicycle Shimano?

    The procedure for repairing and debugging chain drive units should be carried out on a clean bicycle. Be sure to raise the rear wheel, for which they hang the frame on a hook or prepare a special stand.

    As mentioned above, a thorough cleaning precedes a competent setting. Sometimes even such a procedure can have a beneficial effect on the performance of mechanisms. Technological aspects of the preparatory work are as follows:

    • Clean derailleur and sprocket cassette.
    • Clean old grease from tensioner rollers.
    • Wash and lubricate the chain.

    Next, you need to release the hummock, for which the tension screws at the shifter and on the rear spreader are screwed in until they stop. The cable should be pulled out of the clamping screw, but it is not necessary to remove it. It will not hurt to inspect it in order to find damage and, if necessary, treat it with lubricant.

    How to adjust the high gear limiter?

    For alignment, the chain is set to high gear with the smallest sprocket at the back and the largest sprocket at the front. For those who are interested in how to adjust the rear derailleur on a mountain bike, it is important to remember. the essence of the adjustment is to install the rear small chainring in one line with the tensioner rollers. This task is accomplished by rotating the adjusting screw H:

    • clockwise. the frame is deflected towards the large asterisk;
    • counterclockwise. the frame moves to the outside.

    How to adjust the low gear limiter?

    Bike Shifters Won’t Shift. The Most Common Cause

    The function of the L limit screw is to prevent the chain from overshooting the large sprocket. Improper alignment can lead to chain seizure between the sprocket and spokes or the inability to engage low gear.

    Before the adjustment procedure, you need to install the chain so that it is on the back of the large sprocket, and in the front on the small one. Screw L is unscrewed as much as possible so that the switch can move without restriction. The purpose of the setup is to align the tensioner rollers and large chainring in the same plane. The task is performed by rotating the screw L:

    • clockwise. the spreader assembly shifts towards the small sprocket;
    • counterclockwise. the node moves towards the wheel.

    The technological process is simple. it is enough to debug the transition between two adjacent stars, the index gear change system is designed so that the shift will be adjusted on all the stars of the cassette:

    • pull the cable by hand and fix it with the fastening bolt;
    • the final adjustment is carried out by rotating the hollow screw with a drum (position 2 in the figure), the chain should easily move from one star to another and back with one press of the shifter.

    When you finish adjusting the Shimano rear derailleur on a mountain bike, tighten and secure the cable securely. It is important that it fits into the guide groove. If the work is done correctly, then when the pedals are rotated, the chain works silently and does not jump to the side.

    The tensioner is a spreader assembly that provides optimum chain drive rigidity. Excessive tension not only impedes the movement of the chain, but also wears out the gearshift system. The weakened state prevents a clear transition.

    The tensioner assembly is debugged as follows:

    • Place the chain at the rear on the largest sprocket and at the front on the smallest sprocket.
    • If, when moving the chain, the tensioner roller touches the cassette, then you need to tighten the tension screw (position 3 in the figure) so that the gap between them is about 5 mm.
    • Install the chain at the back on the smallest sprocket, and at the front on the largest sprocket, and repeat the operation described in point 2.

    Routine flushing and lubrication of the ropes and their jackets sometimes gives astonishing results. Practice shows that after this operation it becomes much easier to make transitions. If you find a torn cable with a part of unbraided wires, it should be replaced immediately. The same situation with the shirt, which is damaged.

    Unexpected failures when transferring gears can be caused by two reasons:

    • Pulled out the cable from the fixing bolt of the mechanism.
    • At one end of the shirt, a plug was pushed through.

    Before adjusting the rear derailleur on a mountain bike, you need to check the condition of the cock. It may bend from a fall or when driving on uneven surfaces. It is absolutely impossible to straighten the part directly on the bicycle, because the frame of the assembly is fragile, it is better to dismantle the bent cock and align it on a metal plate.

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    You should also pay attention to the degree of wear of the chain drive, which occurs due to a long drive on non-standard gear combinations. Chain tensioner rollers need periodic maintenance. they need to be cleaned and lubricated at least once a year.

    We expose the extreme position of the frame using the bolt L

    To adjust the extreme position of bolt L, you need to switch to the largest sprocket on the rear derailleur (corresponds to the first speed on the shifter). Next, we begin to twist the bolt L until there is a gap of about 1 mm between the chain (which is located on the smallest star of the system) and the switch frame (the smaller the better, the main thing is that the chain does not rub against the switch frame).

    What to do if your bike’s derailleur is broken

    There is no special science in shifting gears on a bicycle; at first glance, everything is simple. Two levers on the left, two on the right, or even just a grip-shift. what could be easier. But nevertheless, observing novice cyclists, one may notice not entirely correct and coordinated actions. But consistency when cycling is the most important thing! This is the only way you will be able to move as efficiently as possible on a bicycle, make maneuvers, overcome obstacles.

    As an example, we will consider the most ordinary mountain bike (MTB) with three stars in front and 8-9 in the back.

    Let’s immediately highlight the most common errors and problems:

    • Too heavy gear is a common mistake. Many newbies even say that 44 (or even 48) stars in the front are not enough for them. It’s a delusion. Constantly spinning a heavy gear you are simply killing your knees. Try to keep track of your cadence (cadence) until it becomes automatic. You can even count the number of revolutions per minute for the sake of interest. If it is around 90-100, then this is very good. And so, gear 44-11 is enough to accelerate on the plain to

    60 km / h So try to convince those who say that 44 stars are not enough for the city. By doing this, you may help to keep people healthy

  • Curve transmission. it is not uncommon to observe how people, without looking at the chain, include gears like 3-1.2. In this case, the chain goes to bend, its wear increases, at the wrong moment it can simply fly off. The optimum chain position is when it passes from the chainring to the rear with minimal skew. So be sure not only to make it easy to twist, but also the position of the chain.
  • Switching under load. so even fragile girls manage to break chains, what to say about healthy men. And what a crunch at the same time. When shifting, reduce the load on the pedals to a minimum, just rotate them with ease until the chain jumps to the desired sprocket. Therefore, it always makes sense to assess the situation, possible obstacles and change gear in advance.
  • Chain biting is when the chain is pulled up by the chainrings when shifting. An unpleasant situation in which the nib near the carriage assembly may be severely scratched. This could be due to cogging on the star, dirt, improper assembly and setup. This is another plus to why you need to watch the shift, and not just mindlessly flip the shifters. All movements should be smooth, even airy.
  • Chain skipping. for example, you put a new chain on an already similar cassette (by the way, the chain resource
  • 1500 km). As a consequence, when the load on the pedals increases, the chain slips and the pedals fail unpleasantly. This must be taken into account and travel more carefully until everything gets used to it. Even for a fairly strong cassette, the rubbing period is about 200 kilometers.

    If you are new to the saddle, pay a lot of attention to pedaling, shifting, try to work with both the front and rear derailleurs. Try to choose a gear depending on the maneuver being made. For example: you slow down, but you will need to accelerate for this. Shift the gear lighter even when braking, then it will accelerate faster.

    The clarity of gear shifting is highly dependent on the technical condition of the bike components. Monitor and, if necessary, replace the cables and shirts in time, the rear derailleur rollers, the switches themselves, the drive elements. the chain, cassette, front sprockets.

    I strongly recommend that you set up the rear derailleur before you start setting / adjusting the front derailleur so that everything works correctly for you. This manual will fit all brands and models of front derailleurs: Shimano, Sram, Microshift, Campagnolo and others.

    • Prerequisites for Configuring a Switch
    • Unscrew the bolt
    • Checking the position of the switch frame
    • Working with a cable and a shifter
    • We expose the extreme position of the frame
    • Checking the clarity of switching
    • Differences between road derailleur setting and MTB

    We expose the extreme position of the frame using the bolt H

    When setting the end position H, we need to switch to the smallest star on the cassette, which corresponds to the largest number on the right shifter from 6 to 11, depending on how many speeds you have there. We throw the chain onto the third star (the largest star on the system) and turn the screw H. Adjust the frame so that the chain does not fly onto the connecting rod with a clearance pedal of 1 mm will be quite enough.

    Checking the clarity of gear shifting.

    Try to change gears and see if the chain goes to all stars.

    often than not, the chain does not go from the second star to the first and clings to the switch frame. This is solved by unscrewing the bolt L (so that the switch frame moves towards the frame) one or two turns and everything should work perfectly.

    Set the center position of the front derailleur frame

    It is necessary to transfer the chain to the center sprockets of the cassette using the rear derailleur. We switch from the first to the second speed (the chain should initially be on the 1st star), if it does not switch, then it is necessary to tighten the cable with the tension regulator (see paragraph 3.A), which is located on the shifter. We twist until the chain clearly and quickly transitions to the middle star.

    Before you start adjusting the front derailleur

    Before you start adjusting the front derailleur, make sure you have the following conditions:

    We start by unscrewing (loosening) the bolt that holds the front derailleur cable.

    5 Shifting Problems You’ll Have And How To Solve Them

    Next, I recommend checking the position of the switch frame relative to the star system.

    If your switch is bolted to the frame, and not with a clamp, as in my case, then you do not need to set the height and angle of the switch, since everything is already exhibited there.

    A. Check the angle of rotation. The switch frame must be parallel to the stars of the system.

    B. Check the height. The front derailleur frame should be slightly higher by 1-3 mm. than the largest star in the system. To adjust, slide the frame by hand so that it is above the 3rd star and adjust the height.

    Most often, new shimano front derailleurs have a sticker that shows how high the derailleur should be.

    Now let’s start working with the cable and shifter on the handlebars.

    A. Find the cable tension bolt on the shifter and screw it all the way into the shifter and turn it half a turn.

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    B. Pull the cable by hand or use pliers and tighten it with the fixing bolt, which I wrote about in paragraph 1. Note that there are special grooves on the washers holding the cable. It is necessary to fix the cable in them.

    We begin to set the extreme positions of the switch frame with bolts H and L.

    High. sets the extreme position at the largest star in the system.

    Low. adjusts the extreme position of the switch on the smallest star.

    Differences between road derailleur setting and MTB

    There is no difference in front derailleur settings on mountain bikes and road bikes. The only thing is that in a road bike, the star system does not use 3 stars, but two stars, which makes the tuning faster.

    bicycle, gear, shifting, broke

    If you have a dual system. You will also need to complete all the points, and in the 4th step there will be no adjustment of the central position, and the tension of the cable will be adjusted when switching to the 2nd star, where there will be an adjustment of the extreme position with the screw H.

    The conveyor device and the reasons for its functional failures

    Before adjusting the rear derailleur on a bicycle, it is useful to find out the reasons for the malfunctioning of the mechanism. The essence of the problem lies in the following points:

    • Cable damage or lack of lubricant.
    • Violation of the integrity of the cable jacket.
    • Curved cock. fastening the mechanism to the bike frame.
    • Worn chain or sprocket cassette.
    • Jammed chain tensioner rollers.
    • Steering wheel gear shift problems.

    Shimano Mountain Bike Rear Derailleur Adjustment Screws: Technical Minimum

    Despite the variety of parallelogram-type spreaders from the Japanese manufacturer, their design and principle of operation are similar. In the process of adjusting the device, five elements are involved:

    • 1. fastening the cable in the form of an embedded bolt with a nut.
    • 2. screw for tensioning the cable with a drum.
    • 3. a screw for adjusting the chain tension.
    • L. limit screw for adjusting low gears.
    • H. limit screw for correcting high gears.

    Special screws L and H, which are used to adjust the rear derailleur of a bike with Shimano Alivio, physically restrict the movement of the mechanism, which prevents the chain from jumping off. In practice, they are used mainly only when debugging a new transfer device, subsequently the procedure is not needed.

    In the event that the cock or the mechanism itself is bent, adjusting the stop screws can solve the problem for a short time. Their sensitivity is not very high, so 1-2 turns at a time are quite justified.

    Technique: how to properly adjust the rear derailleur on a bicycle Shimano?

    The procedure for repairing and debugging chain drive units should be carried out on a clean bicycle. Be sure to raise the rear wheel, for which they hang the frame on a hook or prepare a special stand.

    As mentioned above, a thorough cleaning precedes a competent setting. Sometimes even such a procedure can have a beneficial effect on the performance of mechanisms. Technological aspects of the preparatory work are as follows:

    • Clean derailleur and sprocket cassette.
    • Clean old grease from tensioner rollers.
    • Wash and lubricate the chain.

    Next, you need to release the hummock, for which the tension screws at the shifter and on the rear spreader are screwed in until they stop. The cable should be pulled out of the clamping screw, but it is not necessary to remove it. It will not hurt to inspect it in order to find damage and, if necessary, treat it with lubricant.

    How to adjust the high gear limiter?

    For alignment, the chain is set to high gear with the smallest sprocket at the back and the largest sprocket at the front. For those who are interested in how to adjust the rear derailleur on a mountain bike, it is important to remember. the essence of the adjustment is to install the rear small chainring in one line with the tensioner rollers. This task is accomplished by rotating the adjusting screw H:

    • clockwise. the frame is deflected towards the large asterisk;
    • counterclockwise. the frame moves to the outside.

    How to adjust the low gear limiter?

    The function of the L limit screw is to prevent the chain from overshooting the large sprocket. Improper alignment can lead to chain seizure between the sprocket and spokes or the inability to engage low gear.

    Before the adjustment procedure, you need to install the chain so that it is on the back of the large sprocket, and in the front on the small one. Screw L is unscrewed as much as possible so that the switch can move without restriction. The purpose of the setup is to align the tensioner rollers and large chainring in the same plane. The task is performed by rotating the screw L:

    • clockwise. the spreader assembly shifts towards the small sprocket;
    • counterclockwise. the node moves towards the wheel.

    The technological process is simple. it is enough to debug the transition between two adjacent stars, the index gear change system is designed so that the shift will be adjusted on all the stars of the cassette:

    • pull the cable by hand and fix it with the fastening bolt;
    • the final adjustment is carried out by rotating the hollow screw with a drum (position 2 in the figure), the chain should easily move from one star to another and back with one press of the shifter.

    When you finish adjusting the Shimano rear derailleur on a mountain bike, tighten and secure the cable securely. It is important that it fits into the guide groove. If the work is done correctly, then when the pedals are rotated, the chain works silently and does not jump to the side.

    The tensioner is a spreader assembly that provides optimum chain drive rigidity. Excessive tension not only impedes the movement of the chain, but also wears out the gearshift system. The weakened state prevents a clear transition.

    The tensioner assembly is debugged as follows:

    • Place the chain at the rear on the largest sprocket and at the front on the smallest sprocket.
    • If, when moving the chain, the tensioner roller touches the cassette, then you need to tighten the tension screw (position 3 in the figure) so that the gap between them is about 5 mm.
    • Install the chain at the back on the smallest sprocket, and at the front on the largest sprocket, and repeat the operation described in point 2.

    Routine flushing and lubrication of the ropes and their jackets sometimes gives astonishing results. Practice shows that after this operation it becomes much easier to make transitions. If you find a torn cable with a part of unbraided wires, it should be replaced immediately. The same situation with the shirt, which is damaged.

    Unexpected failures when transferring gears can be caused by two reasons:

    • Pulled out the cable from the fixing bolt of the mechanism.
    • At one end of the shirt, a plug was pushed through.

    Before adjusting the rear derailleur on a mountain bike, you need to check the condition of the cock. It may bend from a fall or when driving on uneven surfaces. It is absolutely impossible to straighten the part directly on the bicycle, because the frame of the assembly is fragile, it is better to dismantle the bent cock and align it on a metal plate.

    You should also pay attention to the degree of wear of the chain drive, which occurs due to a long drive on non-standard gear combinations. Chain tensioner rollers need periodic maintenance. they need to be cleaned and lubricated at least once a year.