How to change the rear derailleur on a bike

How to change the rear derailleur on a bike

How to adjust the rear derailleur

You can understand the principles of the rear derailleur. By adhering to our recommendations, you will say goodbye to the difficulties in the further maintenance of the bike on your own.

Although the gear shifters are simple at first glance, their optimal setting can seem like a rather daunting task. Gear shifting is a sequence of actions that loosen and tighten the cable. The cable without which the rear derailleur will not work. Tuning an old and worn out movement or a cheap model made of low quality metal is a big challenge. After just a couple of years of operation, backlash may form in the switch connections.

How the rear derailleur works?
For the efficiency of tuning, it is advisable to study the device of the component of interest to us. The key principle of operation is based on gear shifting when transferring the chain from one drive sprocket to another, of a different diameter. Let’s start by comparing the front and rear derailleurs. Structurally, the front derailleur is a regular steel frame that moves in different directions. During movement, this chain shifts to the side, from one sprocket to the next.

change, rear, derailleur, bike

The rear derailleur has a more complex mechanism. It has a special spring-loaded foot with small rollers. By dropping the chain onto smaller sprockets, the cyclist uses a shifter to loosen the cable, thereby shifting the chain to the desired sprockets. For chain transfer to a larger sprocket, the shift process is slightly different. In this case, the cable is pulled, after which the foot brings the chain to the star of a larger diameter, friction occurs until it is picked up by the tooth, which will send it to a new gear.

Reasons for the failure of the rear derailleur
1) Mechanical failure. The gear shifter most often breaks down due to mechanical damage, for example, when a cyclist falls on the track. The first step is to make sure it isn’t bent. Ideally, the foot should be parallel to the cassette stars. If there is even a slight bias, you can judge the deformation of the “cock” (rear derailleur bracket), and not the derailleur itself.
Often, after impact, the switch is bent inward, closer to the spokes. Sometimes it hits the knitting needles. It is bad if the frame is not equipped with a removable bracket. then the spokes, the derailleur and the dropout break. all this leads to a breakdown of the frame. The bracket is attached to the frame with a bolt and the rear derailleur is attached to the second bracket. Straightens in a simple way. just pull the switch. But this only works with a slight deviation. Otherwise, you just have to replace the “rooster”;
2) Poor cable lubrication and contamination;
3) Incorrectly adjusted rear derailleur;
4) Deterioration of related parts. Worn out sprockets and flails, rollers in poor condition also lead to breakage. By themselves, poor quality rear derailleur models often break down. A lot of problems can be caused when shifting gears and a malfunction of the shifter.

If you experience difficulty in shifting gears and the bike is unruly on the move, take a close look at the bike. When adjusting, do not pull on the rear derailleur foot only, as this may lead to deformation.

Required tools
You will need: hex keys or a set of them (a 3- and 5-mm key is required), a Phillips screwdriver. Before starting debugging, it is important to make sure that the switch is still functional.

How To Replace Your Rear Derailleur | GCN Tech Monday Maintenance

Preparatory stage
The gear selector is a delicate mechanism in a hard-to-reach place. Therefore, before starting direct adjustment, it is necessary to eliminate key obstacles to the quality of the procedure.

Pay attention to the cleanliness of the bike, its individual mechanisms associated with the operation of the switch. Take care of your bike chain lubrication. Next, the bicycle chain is moved to such a position that it becomes on the small stars in front and behind at the same time. To do this, find on the switch the adjusting screws with the inscriptions H and L. It is necessary to unscrew as much as possible the screw under the letter “L”.

Then unscrew the cable tensioner clockwise as far as it will go. A similar one is located on the shifter. The procedure should be repeated with it. Remember, the rear derailleurs have five key details:
1) Bolt and nut for securing the cable;
2) Screw with hollowness and cable tension adjustment;
3) Screw for limiting the stroke, is transferred to the largest sprocket (L);
4) Limiting screw for small sprocket (H);
5) Tensioning screw for the chain.

Some cheap models do not have cable and chain tensioners. The final preparatory operation is to unscrew the screw that secures the cable directly to the switch. If rust forms, it must be replaced. Slight wear of the part indicates further operation with a prerequisite for cleaning and lubrication. Place the chain on the smallest chainring at the front and the largest chainring at the back, then pedal backwards. Then the upper roller of the rear derailleur, turning the tension screw, bring it as close to the star as possible, but so that it does not touch it. Such actions will help to achieve smooth gear shifting. At the end of the preparation check the ease of sliding of the cable through the “shirt” on the bike frame. Sometimes it needs to be rinsed.

Basic setting
Begin adjusting by checking the position of the top roller. it should be on the same vertical line or slightly to the left of the smallest cassette star above it, or slightly offset to the left when viewed from behind. The position can be corrected with the adjusting screw marked “H”. Turn the screw clockwise to move the roller to the left, and vice versa to move the roller to the right. Set up the high gear limiter like this:
1) put the largest star in the front and the smallest in the back;
2) loosen the shift cable by unscrewing the switch holding the bolt. You can screw in the cable tension adjustments on the switch and on the shifter to the maximum;
3) make sure that both rollers are in the same plane with the smallest sprocket;
4) at the end of the adjustment, it is necessary to pull the cable and clamp it on the switch.

After installing the cable, you need to go to the setting of small gears. Place the chain on the rear sprocket with the largest diameter. Next, check the position of the rollers under the large sprocket. The bolt responsible for the position of the rollers is located under the letter “L”. Adjust the chain if the speed selector has the ability to adjust the tension level. Each cyclist selects the optimal settings for himself. it is advisable to remember them in order to ensure a comfortable use of the bike.

Tension setting
Modern models have two spring-loaded levers. The lower one raises the switch frame upward, when positioned on small stars. The upper one provides movement of the frame back to the large star. The spring tension of both levers must be balanced for correct gear shifting.

By setting the chain to the lowest gear, when the screw is loosened, the guide roller rises, approaching the star, reducing the angle of inclination of the chain. this improves the quality of shifting. The roller should not touch the sprocket and the gap should be approximately 5 mm. It is advisable to do this procedure when replacing the cassette or when changing the chain length.

How to switch gears correctly
After adjusting the rear derailleur, you need to make sure that the gears are shifted correctly. Thoughtless “clicking” of the switch is not the best solution for testing the switch functionality. The key rule is that gear changes are carried out while the bike is moving. Before changing the speed, it is advisable to apply less pedal pressure. Change gears sequentially. If you want to climb a mountain on the move, change the gear to a lighter one before starting the actual climb. To descend from a hill, the same rule is relevant, but you only need to switch to a gear in which it is more difficult to pedal.

Combinations of correct star combinations for different riding
Experienced cyclists select the optimal sprocket combinations for a comfortable ride with their bike model. The most popular combination is:
for city driving and asphalt roadway outside the city. a large front and between the 4th and 8th rear sprockets;
for cross-country travel or for fast driving on the track. a combination of a large chainring with driven ones (3rd and 6th);
when going uphill. a combination of a small leading star with driven ones (from 1st to 3rd).

Too much misalignment of the chain will shorten its life. As soon as there is a sudden extraneous sound when driving, stop immediately and check the switch for faults.

Caring for cables and shirts
Sometimes it is enough to keep the shirts and cables clean and lubricate them regularly with liquid oil. It is then much easier to adjust the bike‘s rear derailleur. Switches of different rulers and manufacturers serve different periods. it all depends on the price range. But even the durability of cheap switches can be extended with gentle handling and care.

How To Replace/Upgrade Rear Derailleur On A Bike

A cable shirt is needed to keep out dirt. If you find a torn cable with unbraided threads, then hurry up to replace it with a new one.
In case of corrosion of the cable and constant jamming in the jacket, it is better to treat it with graphite grease. The rear derailleur adjustment will then advance faster and the gear shifting will remain as smooth as before. Damaged shirts should be replaced.

Diagnosing a cock problem
If the chain throwing by the rear derailleur fails, there is a reason to check the “rooster” for serviceability. The rear derailleur often suffers from damage. There is a huge load on it. Often from a strong blow to the log and the curb, the “rooster” bends or bursts. Therefore, make sure that the two tensioner rollers are strictly vertical to each other.

The dissonance of the geometrical parallels of the rollers means breakage. The chain, passing along the rollers, must be strictly vertical. without distortions. Do not level him in a field, forest, snowy mountains. Trying to straighten it by hand will only bend the switch frame. Experts do not recommend that you straighten a curved “cock” by pulling on the switch. Its frame is very fragile. First, it will bend, then the fasteners will deteriorate. this will only aggravate the situation with the repair. It is better to completely remove the cock, spread it out on a flat surface and use tools in attempts to straighten.

By following our instructions, you can independently consolidate your theoretical knowledge of a bicycle in practice. No one but you can actually make it work: only you know all its pros and cons.

The most common derailleurs on the market are from two manufacturers: Sram and Shimano. Our articles will tell you more about the variety of models of switches from these manufacturers:

Steps for adjusting the rear derailleur on a speed bike.

  • Needs to switch to smallest sprockets in front and back.
  • The tensioner drums (on the switch and on the shifter, if available) must be turned to the initial value, turned clockwise until they stop. This will make it possible for us in the future, when the rear derailleur cable is weakened, to tighten the cable using this drum.
  • We unscrew the screw or nut, weaken the cable itself. In this case, you can pull out the cable and check for defects or contamination of the cable jacket.
  • Adjustment of large gears with screw “H”. It is necessary to turn the adjusting screw “H” until the derailleur rollers and the small sprocket are on the same straight axis. If, when switching to large gears, there is a shift of the rollers relative to the stars to the right, then it is necessary to turn the screw “H” clockwise, tighten, until they become exactly on a straight axis. If the rollers are shifted to the left, it will be difficult for the chain to switch to lower gears, it is necessary to loosen the “H” screw. turn it counterclockwise. With the correct adjustment of large gears while rotating the wheel by turning the pedals, the chain should work silently without hooks on a small star.
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Further, it transcends the adjustment of the chain tensioner, if any. To do this, place the chain on the smallest front sprocket and the rear on the largest. Then we pedal back, if the upper roller of the rear derailleur touches the teeth of the sprocket, then it is necessary to turn the adjusting screw to achieve such a value so that the roller is at a distance of about 5 mm from the teeth of the sprocket. Then we need to check the chain tension, only now we need to switch to the small rear sprocket.

The last step is to check the correctness and clarity of gear changes. It is best to sit down and ride a bike, while checking each gear for clear shifting. A correctly tuned rear derailleur of a high-speed bike is considered if all gears shift clearly without chain crackling, the chain should move clearly from extreme stars to adjacent ones and vice versa.

Bicycle Rear Derailleur Adjustment

After we have eliminated all 5 possible problems with the rear derailleur, we can begin to configure it. I took a bike with a shimano rear derailleur and divided the whole setup into 8 steps:

On the shifter, we throw off to the highest speed (which corresponds to the smallest star on the block of led stars). We pedal so that the chain is on a small star. (now you understand why it is so convenient to work with the rack)

I don’t see numbers on the shifter, but believe me the position of the indicator is on the “number” 9. Which corresponds to the smallest star on the cassette.

When adjusting the rear derailleur on the sprockets (front), it is best to place the chain where you use it most. This is usually the central star on a 3-star system.

Loosen the hexagon or bolt that holds the cable.

We twist it all the way, and then return one turn back all the adjusting thumbs of the cable tension, which are located on the switch and on the shifter (sometimes there is only one adjustment screw on bicycles, most often it is on the switch, less often on the shifter).

In my case, the cable tension regulator is located only on the shifter. The photo shows how I twist the lamb.

We pull the cable with our hand (it is not necessary to pull with all our strength, the main thing is that it does not sag and be stretched along its entire length) and tighten the bolt holding the cable.

Align the center of the derailleur foot rollers with the center of the smallest chainring on the bike. Some people remove the chain for stages 5 and 6 to fine tune them. I do not see the need for this, you can not shoot, especially if you have a switch that is not of the top level, such as shimano tourney, acera or alivio.

Actually, all this movement of the switch occurs using the adjusting screws with the letters “H” and “L”.

We turn the screw “H” with a screwdriver until the centers of the rollers on the foot of the switch and the small star coincide and go to the next step.

In the photo, I showed a red line, along which you can see that the switch roller is under a small star on the cassette, which means that the extreme position is set correctly.

We switch on the shifter to the lowest speed (number 1), which corresponds to the largest driven star. We twist the pedals so that the chain goes to the extreme sprocket. And also align the center of the foot rollers with the center of the largest sprocket. All this alignment takes place with the screw “L”.

On the shifter, the indicator for switching the speed to number 1, if there are no numbers in the most extreme position, which should correspond to the largest star on the cassette.

Essentially, the “H” and “L” screws act as end stops for your derailleur, which keeps the chain from flying off while driving and keeps you alive.

We drop again at the highest speed. Remember to pedal? The chain should be on the smallest star. Next, switch to one speed and turn the pedals, if the chain does not jump or does not jump right away, then you need to slightly unscrew the adjusting screw that adjusts the cable tension (it turns out we are pulling the cable).

Then again we check and switch from the highest speed one step lower (if an 8-speed cassette, then from 8 to 7 speed), if the switch happened immediately, congratulations you set the switch! You can check the remaining speeds will also easily and clearly switch both up and down.!

The chain should jump to the adjacent speed. In my case, this is a 9 speed cassette. Switching from 9 to 8.

Adjust the distance from the largest star to the derailleur roller. This distance should be about 4 mm, if the distance is greater, the switching clarity will be reduced. The adjusting screw on the switch is responsible for adjusting this gap. By unscrewing the screw, the distance decreases, screwing it in increases. tuning is done on the largest star corresponding to the number 1 on your shifter.

Reasons for the deterioration of the rear derailleur:

Lack of service. Most often, when buying a bike, the derailleur works well and flawlessly, but after the season of operation, you can replace the deterioration in performance or even the chain jumping off the extreme sprockets. In 70% of cases, setting the rear derailleur helps, but sometimes this does not help either, then the cable and shirt should be replaced, as they become clogged with dirt and interfere with the smooth running of the cable in the shirt. Usually bike maintenance is done once a year, in which the switch settings are turned on.

Sometimes, to save money, they lubricate the cable with grease or any other lubricant and it turns out to improve the work for a while, but later the lubricant attracts dust to itself and the work deteriorates again, so you will have to do this procedure more often than you would like.

Deterioration of the switch itself. Everything ever breaks down and the derailleur on a bike is no exception. Most often, the parallelogram axes of the switch wear out, due to which a small backlash is formed, which does not allow the switching to be set correctly.

Derailleur sprockets are worn. Over time, plastic sprockets wear out due to which the chain no longer holds on to them, which leads to poor operation of the derailleur. Also, the sprocket axles can wear out and the sprocket will dangle unnecessarily on the axle, which leads to poor shifting.

Curve cock or the switch itself. When you fall or hit something with the switch, the cock will most often bend (break), since it is made specially from a weaker alloy than the switch itself (to keep the more expensive part intact). The curvature does not allow the chains to stand up exactly, which reduces the efforts to adjust the crossover to zero. Read how to straighten a cock with your hands.

Cable problems. Sometimes, during installation or when dropped, the cable may bend strongly, after which the place of the bend will prevent the smooth movement of the cable in the shirt. In this case, its replacement is required.

It also happens that the cable gets loose (that’s why you should use the ends of the cables) and subsequently one of the thin threads begins to separate from the main bundle, as a result, interferes with the normal movement of the cable in the shirt. Sometimes one thread in the cable can break and also prevent it from working normally, here you can isolate it from the main bundle along the entire length of the cable. But the best option would be to replace the cable with a new one.

If a new cable was installed, then sometimes after a certain number of kilometers (about 100 km), you can notice a deterioration in switching. this is due to the fact that the cable is slightly stretched. In this case, it will be necessary to tighten the cable tension bolt a little.

Important! If at least one of the 5 problems you have, it will not be possible to adjust the switch perfectly!

If, after completing all the steps, you cannot clearly adjust the rear derailleur of the bike, then most likely the rear derailleur needs repair or replacement.

Perhaps the lever is bent due to falls or other circumstances, you can try to repair the rear derailleur by aligning the lever.

Not clear switching can also be due to a cassette not working properly, various deformations, distortions. Also, the reason for a fuzzy shift may be hidden in a dirty cable or a malfunction of the shift lever. After the correct setting of the rear derailleur, you can proceed to the speed bike front derailleur setting.

Sooner or later, the rear derailleur wears out and it becomes necessary to replace it. Then the question arises about the interchangeability of the rear derailleurs. Switches can be categorized according to the following parameters:

  • Switch frame length. this parameter is responsible for the so-called switch capacitance. That is, the length of the derailleur frame is responsible for the gear ratio range with which the rear derailleur can operate. Simply put, the capacitance of the derailleur is the sum between the difference between the small and large stars of the cassette and the system. For example, if the cassette is 11-32T, and the system is 22-44T, then the required capacity can be calculated using the following formula. (32-11) (44-22) = 43T. 43T is the minimum allowable capacity of the rear derailleur. The numbers indicate the number of teeth of the stars.
  • Spring Direction. Indicates in which direction the switch is operated by the spring. The most popular direction is Top normal, that is, shifting due to the cable is carried out from a smaller sprocket to a larger one. All rear derailleur manufacturers adhere to this principle. But there is also a reverse direction (Low normal), when the chain is dropped by a cable to small stars, and switching to large stars is carried out by means of a spring. Rear derailleurs with this direction are only found in the Shimano range. These switches do not have significant advantages, and therefore did not gain popularity.
  • The drive ratio is the ratio of cable movement to derailleur movement. This ratio can be 2: 1 (Shimano) or 1: 1 (Sram). It is these indicators that do not allow the switches of these manufacturers to be interchangeable. It is worth noting that there is no difference in the clarity of gear shifting from this indicator, although Sram claims the opposite (in practice, there is no evidence).

Preparing to adjust the rear derailleur

Proceeding to setting the rear derailleur, it is necessary to clean the main elements that are included in the gearshift system.

It is required to clean the cassette of dirt, the rear derailleur itself, check the cable shirts, and it is also advisable to lubricate them if necessary.

How to change the rear derailleur on a bike

Every cycling enthusiast should know how to properly adjust the rear derailleur. If the mechanism fails, its normal operation will come to naught. The operation of the rear derailleur seems to many cyclists difficult and incomprehensible, hidden from prying eyes. The mechanism can easily and unpretentiously perform its functions, but one day it will fail. If you have no experience in fixing a similar problem, take your bike to a workshop, where a qualified technician will fix the problem within a few minutes.

You can understand the principles of the rear derailleur. By adhering to our recommendations, you will say goodbye to the difficulties in the further maintenance of the bike on your own.

Although the gear shifters are simple at first glance, their optimal setting can seem like a rather daunting task. Gear shifting is a sequence of actions that loosen and tighten the cable. The cable without which the rear derailleur will not work. Tuning an old and worn out movement or a cheap model made of low quality metal is a big challenge. After just a couple of years of operation, backlash may form in the switch connections.

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How the rear derailleur works?
For the efficiency of tuning, it is advisable to study the device of the component of interest to us. The key principle of operation is based on gear shifting when transferring the chain from one drive sprocket to another, of a different diameter. Let’s start by comparing the front and rear derailleurs. Structurally, the front derailleur is a regular steel frame that moves in different directions. During movement, this chain shifts to the side, from one sprocket to the next.

The rear derailleur has a more complex mechanism. It has a special spring-loaded foot with small rollers. By dropping the chain onto smaller sprockets, the cyclist uses a shifter to loosen the cable, thereby shifting the chain to the desired sprockets. For chain transfer to a larger sprocket, the shift process is slightly different. In this case, the cable is pulled, after which the foot brings the chain to the star of a larger diameter, friction occurs until it is picked up by the tooth, which will send it to a new gear.

Reasons for the failure of the rear derailleur
1) Mechanical failure. The gear shifter most often breaks down due to mechanical damage, for example, when a cyclist falls on the track. The first step is to make sure it isn’t bent. Ideally, the foot should be parallel to the cassette stars. If there is even a slight bias, you can judge the deformation of the “cock” (rear derailleur bracket), and not the derailleur itself.
Often, after impact, the switch is bent inward, closer to the spokes. Sometimes it hits the knitting needles. It is bad if the frame is not equipped with a removable bracket. then the spokes, the derailleur and the dropout break. all this leads to a breakdown of the frame. The bracket is attached to the frame with a bolt and the rear derailleur is attached to the second bracket. Straightens in a simple way. just pull the switch. But this only works with a slight deviation. Otherwise, you just have to replace the “rooster”;
2) Poor cable lubrication and contamination;
3) Incorrectly adjusted rear derailleur;
4) Deterioration of related parts. Worn out sprockets and flails, rollers in poor condition also lead to breakage. By themselves, poor quality rear derailleur models often break down. A lot of problems can be caused when shifting gears and a malfunction of the shifter.

If you experience difficulty in shifting gears and the bike is unruly on the move, take a close look at the bike. When adjusting, do not pull on the rear derailleur foot only, as this may lead to deformation.

Required tools
You will need: hex keys or a set of them (a 3- and 5-mm key is required), a Phillips screwdriver. Before starting debugging, it is important to make sure that the switch is still functional.

Preparatory stage
The gear selector is a delicate mechanism in a hard-to-reach place. Therefore, before starting direct adjustment, it is necessary to eliminate key obstacles to the quality of the procedure.

Pay attention to the cleanliness of the bike, its individual mechanisms associated with the operation of the switch. Take care of your bike chain lubrication. Next, the bicycle chain is moved to such a position that it becomes on the small stars in front and behind at the same time. To do this, find on the switch the adjusting screws with the inscriptions H and L. It is necessary to unscrew as much as possible the screw under the letter “L”.

Then unscrew the cable tensioner clockwise as far as it will go. A similar one is located on the shifter. The procedure should be repeated with it. Remember, the rear derailleurs have five key details:
1) Bolt and nut for securing the cable;
2) Screw with hollowness and cable tension adjustment;
3) Screw for limiting the stroke, is transferred to the largest sprocket (L);
4) Limiting screw for small sprocket (H);
5) Tensioning screw for the chain.

Some cheap models do not have cable and chain tensioners. The final preparatory operation is to unscrew the screw that secures the cable directly to the switch. If rust forms, it must be replaced. Slight wear of the part indicates further operation with a prerequisite for cleaning and lubrication. Place the chain on the smallest chainring at the front and the largest chainring at the back, then pedal backwards. Then the upper roller of the rear derailleur, turning the tension screw, bring it as close to the star as possible, but so that it does not touch it. Such actions will help to achieve smooth gear shifting. At the end of the preparation check the ease of sliding of the cable through the “shirt” on the bike frame. Sometimes it needs to be rinsed.

Basic setting
Begin adjusting by checking the position of the top roller. it should be on the same vertical line or slightly to the left of the smallest cassette star above it, or slightly offset to the left when viewed from behind.

After installing the cable, you need to go to the setting of small gears. Place the chain on the rear sprocket with the largest diameter. Next, check the position of the rollers under the large sprocket. The bolt responsible for the position of the rollers is located under the letter “L”. Adjust the chain if the speed selector has the ability to adjust the tension level. Each cyclist selects the optimal settings for himself. it is advisable to remember them in order to ensure a comfortable use of the bike.

Tension setting
Modern models have two spring-loaded levers. The lower one raises the switch frame upward, when positioned on small stars. The upper one provides movement of the frame back to the large star. The spring tension of both levers must be balanced for correct gear shifting.

By setting the chain to the lowest gear, when the screw is loosened, the guide roller rises, approaching the star, reducing the angle of inclination of the chain. this improves the quality of shifting. The roller should not touch the sprocket and the gap should be approximately 5 mm. It is advisable to do this procedure when replacing the cassette or when changing the chain length.

How to switch gears correctly
After adjusting the rear derailleur, you need to make sure that the gears are shifted correctly. Thoughtless “clicking” of the switch is not the best solution for testing the switch functionality. The key rule is that gear changes are carried out while the bike is moving. Before changing the speed, it is advisable to apply less pedal pressure. Change gears sequentially. If you want to climb a mountain on the move, change the gear to a lighter one before starting the actual climb. To descend from a hill, the same rule is relevant, but you only need to switch to a gear in which it is more difficult to pedal.

Combinations of correct star combinations for different riding
Experienced cyclists select the optimal sprocket combinations for a comfortable ride with their bike model. The most popular combination is:
for city driving and asphalt roadway outside the city. a large front and between the 4th and 8th rear sprockets;
for cross-country travel or for fast driving on the track. a combination of a large chainring with driven ones (3rd and 6th);
when going uphill. a combination of a small leading star with driven ones (from 1st to 3rd).

Too much misalignment of the chain will shorten its life. As soon as there is a sudden extraneous sound when driving, stop immediately and check the switch for faults.

Caring for cables and shirts
Sometimes it is enough to keep the shirts and cables clean and lubricate them regularly with liquid oil. It is then much easier to adjust the bike’s rear derailleur. Switches of different rulers and manufacturers serve different periods. it all depends on the price range. But even the durability of cheap switches can be extended with gentle handling and care.

A cable shirt is needed to keep out dirt. If you find a torn cable with unbraided threads, then hurry up to replace it with a new one.
In case of corrosion of the cable and constant jamming in the jacket, it is better to treat it with graphite grease. The rear derailleur adjustment will then advance faster and the gear shifting will remain as smooth as before. Damaged shirts should be replaced.

Diagnosing a cock problem
If the chain throwing by the rear derailleur fails, there is a reason to check the “rooster” for serviceability. The rear derailleur often suffers from damage. There is a huge load on it. Often from a strong blow to the log and the curb, the “rooster” bends or bursts. Therefore, make sure that the two tensioner rollers are strictly vertical to each other.

The dissonance of the geometrical parallels of the rollers means breakage. The chain, passing along the rollers, must be strictly vertical. without distortions. Do not level him in a field, forest, snowy mountains. Trying to straighten it by hand will only bend the switch frame. Experts do not recommend that you straighten the bent “cock” by pulling the switch. Its frame is very fragile. First, it will bend, then the fasteners will deteriorate. this will only aggravate the situation with the repair. It is better to completely remove the cock, spread it out on a flat surface and use tools in attempts to straighten.

By following our instructions, you can independently consolidate your theoretical knowledge of a bicycle in practice. No one but you can actually make it work: only you know all its pros and cons.

Original publication. on cortobike.ru

Possible errors when setting the rear derailleur

Question: What if I unscrewed the adjusting screw to the end, and the chain still does not switch to 1 speed lower?
Answer: Most likely you pulled the cable poorly by hand from step 4, or you did it with insufficiently tightened cable tension adjusting screws from step 3, and it is also possible that you did not pull the cable at the highest speed on the shifter described in step 1.

Question: I reached stage 7, but the chain was not on the smallest star why?
Answer: You may have pulled the cable too tight by hand in step 4, in which case try to loosen the cable tension slightly with the adjusting screw. If the chain still does not go to the extreme small star, repeat steps 1 to 4.

How to install a rear derailleur on a bike?

Having clocked many kilometers on a bicycle, I was convinced that a branded derailleur is much more important for a comfortable ride than stylish grips or leather Brooks. But it’s not enough just to get Shimano or Sram, the quality of installation and setup is important.

What is the rear derailleur made of?

The material of manufacture can be different: from stainless steel to titanium. On budget bicycles, as a rule, steel and plastic switches are installed. such products are short-lived, work poorly. Models of the middle price segment are equipped with an aluminum movement, and the most expensive ones are composed of composite, carbon and titanium.

Preparatory operations for setting

All the guides written on how to set up the rear derailleur on your bike have tips on how to properly prepare your bike for this first step. The fact is that the speed switch is a rather thin device located in a relatively inaccessible place. Before you start to regulate it, it will be necessary to eliminate all the reasons that prevent the correct implementation of such a procedure.

You should pay special attention to the cleanliness of the bike and its individual structural elements. the cassette with stars and the derailleur itself. In addition, the bike chain will need to be lubricated. Such operations will allow you not to get dirty and clearly see those nodes that you have to adjust.

The next stage of the preparatory work will be the transfer of the bicycle chain so that it stands on the stars of the smallest diameter, both front and rear. To do this, you will need to find the adjusting screws located on the switch, which are labeled: H (high) and L (low). Their purpose is to adjust high and low range gears. Here you need to unscrew the screw under the letter “L” to the maximum value.

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Before you start adjusting your bike, you need to clean and lubricate it.

After the screw is unscrewed, it is necessary to turn the drum until it stops, moving clockwise. This cable tension drum is not installed on all models of modern bicycles. This is worth bearing in mind. A similar drum is usually placed on the shifter. It also turns in a similar way, while you will need to stop without screwing about 4 turns all the way.

One of the final steps in preparing the bike derailleur is to loosen the screw that secures the cable directly to the derailleur. If it is rusty and dirty, then it will have to be replaced. In the case when it is not too worn out, namely, it is not visible that it is unraveling, clean it and lubricate.

It will be necessary to check the ease of sliding of the cable through the “jacket”, which is a plastic tube mounted on the bike frame. The fact is that in most cases the gears change poorly precisely because they are clogged with dirt. To prevent this from happening, “shirts” must be washed.

Correct gear shifting

Now that you’ve figured out how to set up the rear derailleur on your bike, it’s worth investigating how to properly shift the gears on your bike. The fact is that if you do not “click” the gear shift knob, but approach the issue of their choice responsibly, you will significantly extend the life of your bike.

Important! The first rule of thumb to change gears on a bike is that you can only do this when the bike is moving.

If you try to change the speed in a stationary position of the vehicle, it can lead to failure of the transmission. Before you start shifting, the pressure on the pedals will need to be released.

If you need to change gears quickly, try to do so consistently without jumping over them. The fact is that when you miss a few gears, it can break the stars and the derailleur itself. In the same case, when this procedure is carried out sequentially, all units and parts of the transmission will not be damaged.

If you do not know how to adjust the rear derailleur on a bicycle, try not to “throw” the chain between the front sprockets when riding uphill, as this will simply knock the derailleur setting. If you decide to switch between the rear sprockets in this way, then this does not contradict the requirements of the bike’s instruction manual.

It is worth remembering the following rule: if you want to overcome a hill, shift the gear up before starting to climb it. By doing this, you will not only save your strength, but also protect the transmission from damage. The same rule applies when descending from a hill.

How to install a rear derailleur on a bike

Installation and adjustment

Reference: The Shimano Tourney TX is the entry-level model, although the exterior design suggests a higher class.

So, replacing the rear derailleur starts with removing the old noname from the frame. it’s time for Shimano. The link of the chain is revealed. If this is not the case, then you need to use squeeze.

The old switch is unscrewed and removed, and a new one is hung in its place and screwed to the “cock”. a protruding triangle with a hole in the frame. It is worth tightening well, but without undue enthusiasm.

We put the bike chain on the smallest star. Visually, the roller and small star should be in the same line. The small star is the highest speed, therefore we adjust the position of the roller with the screw H.

Help: the letter H is an abbreviation for high gear, that is, top gear.

The next step is to insure against the possibility of the chain hitting the spokes, which is likely if the derailleur goes behind the largest sprocket. To do this, you need to move the switch to the largest star, carefully and without unnecessary effort. In no case by the roller, the mount of which is very easy to bend.

The adjusting screw fixes the position of the switch exactly so that it is opposite the large sprocket. Going behind it is fraught with the loss of knitting needles and good mood. If the switch is too tight, there will be no lower gear.

Queue for the cable. he should walk freely in a shirt. We check the progress and the absence of creases. On this switch model, you can see the place for the cable to pass. We put the chain on the smallest sprocket, tighten the cable to remove the slack, fix it. Thus, installing the rear derailleur and adjusting it are two integral, complementary processes.

Now check the operation of the entire mechanism. There should be no pronounced clicking sounds when pedaling from the rear derailleur side. Switching up and down should be accurate, without jumping and delays. And even if everything fell into place, it works accurately, quietly and without delay. for the first trip it is worth taking a screwdriver with you. Working with a load may well require minor adjustments.

Note that you will have to face such a concept as “preventive maintenance of the switch”, regardless of its price category. As the rollers, which are consumables, wear out, their timely replacement will be required.

It is believed that installing and adjusting the rear derailleur is much easier than the front derailleur. However, you will have to spend time and effort, but this work will pay off handsomely during the trip.

How to put a rear derailleur on a bike

Having traveled many roads on a bicycle, you are convinced that for a comfortable ride, buying stylish grips and choosing the right tires is not enough, much more important is the presence of a branded rear derailleur, which will be correctly installed and configured.

The gearshift mechanism was invented by Tullio Campagnolo in 1950. This discovery made a splash among bike manufacturers, who from that moment on, polls began to equip new models with this device.

The main purpose of the mechanism is to increase or decrease speeds by throwing the chain over the stars in the cassette. In addition, the rear derailleur on the bike prevents the chain from sagging by keeping it taut. than half a century has passed since the invention of the device, during which time many of its varieties have been created.

The number of gears that you can choose depends on the length of the frame: the longer it is, the more speeds are provided by the design of the bike. However, it is impossible to say unequivocally that a long frame is better, someone likes a short frame that is not afraid of stones. And here everyone is right in their own way!

Adjusting the bike’s rear derailleur yourself.

Adjusting the rear derailleur on a bicycle is a process that many people find very difficult and only accessible to experienced mechanics. In fact, it turns out that not everything is so terribly complicated and everyone can deal with this procedure. over, it is often necessary to adjust the correct operation of the rear gearshift mechanism on a bicycle. And it’s better to learn this yourself than to endure unbearable cod and chain slip on the way to the workshop. We have prepared instructions for you, which we use ourselves, we assure you that you will succeed! So let’s go:

  • Loosen the rear derailleur cable as much as possible, to do this, switch to the fastest gear (small sprocket at the back), and tighten all the screws that adjust the cable tension. If there is too much slack or looseness, unscrew the retaining screw on the rear derailleur and pull the cable a little.
  • Test the rear derailleur by lifting the wheel off the ground and gently pedaling back and forth. If the chain in this position of the rear derailleur strives to jump down from the smallest sprocket, adjust the lower position of the derailleur with the screw marked H. screw it in slowly. If, on the contrary, with a loosened cable, the chain tries to jump higher to a large sprocket, then unscrew the adjusting screw H.
  • Make one click of the shifter to change to a lighter gear. If the rear derailleur does not move the chain to the next sprocket, turn the adjusting screw on the derailleur counterclockwise, this will cause the derailleur to move the chain to the left, thereby throwing it one star higher. Important! In each gear, the upper roller of the rear derailleur must be in the same plane with the sprocket that corresponds to the set speed on the shifter.
  • If the chain went over to the desired sprocket and strive to jump further, or immediately jumped over one star, turn the adjusting screw clockwise. This will loosen the cable a little and cause the rear derailleur to move to the right, thereby moving the chain into the correct gear.
  • Set the lightest gear on the shifter, which corresponds to the largest sprocket in the back. If the rear derailleur tries to reset the chain towards the spokes, limit its movement by tightening the screw L. But if, on the contrary, something prevents you from changing the speed to the lightest (there is no click on the shifter or it happens but the chain cannot jump to the last star), on the contrary. remove screw L.
  • Pedaling forward quickly, test the rear derailleur in each gear towards set and reset. If problems arise when changing speeds up or down, repeat steps 3 and 4.

But, as they say, it’s better to see once:

When adjusting the rear derailleur on your bike, keep in mind

  • the chain must be cleaned and lubricated, in which case it becomes much more elastic and easily moves with the switch in the right direction;
  • shirts leading the cable from the shifter (monoblock) to the rear derailleur should not have too much bends or come in at a very sharp angle. Thus, the movement of the cable inside the shirts will be difficult, and you can spend a lot of time adjusting the rear derailleur without achieving a result;
  • the rear derailleur frame must be strictly parallel to the stars (wheel). If there was a fall to the right side, or if you just caught something with the rear derailleur, it could bend the earring that secures the derailleur and knock off the setting;
  • check for foreign matter between the stars at the back. It often happens that grass, weed, dirt, and sometimes even wire are stuffed into the cassette (ratchet) and this prevents the chain from taking its correct position;
  • check if the bike chain is stretched? It often happens that the owner missed the moment when it was necessary to change the chain, in this case, interruptions in the operation of the rear derailleur are possible;

Reverse derailleur setting

The principle of operation of the rear derailleurs is exactly the same as usual. Except for the direction in which the tension of its foot occurs. In this case, start the adjustment of the rear derailleur with the lightest gear (largest sprocket in the back), and all other procedures are the same.

As you can see, adjusting the rear derailleur on a bike is not that difficult. The main thing is to understand its structure, have the necessary tools and read our instructions several times. And if you have any difficulties. feel free to contact us, we will show you how to be in your situation.