How to assemble a derailleur on a bike

On planetary bushings

Gear shifting in planetary hubs is completely different from the usual described mechanism, but also requires periodic adjustment. A pusher is responsible for changing gears on planetary gears. a small element resembling a chain connecting the shifting mechanism inside the hub with a cable.

In order to adjust everything well, it is necessary to find the slot on the pusher (the connection point of the rigid and movable parts of the device) and at the penultimate speed align it with the wheel axis (for this, special viewing windows are usually provided). The setup steps are as follows:

  • We set the penultimate speed: 2 for a three-speed hub, 3 for a four-speed.
  • We remove the boot or other protection of the connection point of the cable to the pusher.
  • We release the pusher and find the required point, tracing through the viewing window the coincidence of the spline and the wheel axis.
  • We tighten the cable with a screw, aligning the pusher.
  • Close protection.

It is difficult to make any other shift setting for the planetary hub on your own. You will need to completely disassemble all the mechanisms, which is quite problematic at home.


Actually, this is what is usually called switch adjustment ¬– this is working with High and Low limiters. The point is to keep the chain from falling off the sprockets in extreme positions. This setting is done simultaneously on the front and rear sprockets with the (ideally) disconnected cable. Those. first, the adjustment is made, and only then a cable is wound under the screw and pressed. This increases accuracy and eliminates tensioning effects that can interfere with work.

What do you need to know? Each switch has two adjustment screws, usually marked with two letters:

  • H. high or hard. high, the position of the chain on the largest star in front and the smallest in the back;
  • L. low or light. low, position on the smallest chain at the front and the largest at the back.

The purpose of the adjustment is to set the chain on the corresponding stars, rotate the corresponding bolts with a screwdriver until the chain is parallel to the frames and, accordingly, with the correct installation of the mechanism itself, parallel to the plane of the wheel and the stars. Additional conditions:

  • The chain should not fly off when switching to the extreme sprocket.
  • The frame or chain must not touch the axle and frame.
  • The chain must not scrape against the derailleur.

After adjustment, the entire mechanism should be assembled and checked for correct operation. All transitions must be clear so that the chain does not sag or touch the frame or frames. The shortcomings revealed in this test drive require a serious approach, because they can speak not only of incorrect tuning, but also of other problems in the bike, and it is better to fix it right away, and not expect serious damage.

assemble, derailleur, bike

How to properly adjust the derailleur on a bike?

Before proceeding to setting the speed switch, you should understand its place in the entire drive mechanism and general settings, because, in addition to setting, the switch must be correctly set, the correct switching system must be suitable for it, and the chain must fit the stars. Problems with the switching system are not always caused by an incorrect setting, but with a poor installation or an erroneous selection of a combination of elements. In addition, by mistake, elements that do not match each other may be placed on the bike.

Angle adjustment

The second problem is both installation and configuration. The entire device must be parallel to the stars of the common frame axis. This is determined by special devices or by checking the parallelism by eye: we simply bring the bike to the mowing line so that one of the edges of the wheel, bushing or other landmark is on one mowing line and becomes invisible, and we check if our chain or frame does not diverge.

In case of serious deviations, we work with the installation of the switch, you may even have to remove the device, with small deviations. with special adjustment screws, if there are any on our model.


  • Checking the cable (it must be properly closed with a jacket, it must be easy to pull and respond to the operation of the shifters).
  • Checking the shirts (on the surface of both the cable and shirts there should be no serious damage or obvious bends, as they will eventually lead to blocking of switching in one way or another).
  • Connection (the cable must be wound and clamped in the receiver without protruding burrs and sagging places).

The second step is to install and secure the switches. This is necessary if the switch is being adjusted after it has had to be repaired or replaced. The third step is threading the chain. Before fastening the switches (the circuit must be threaded into them) or, conversely, after fastening (the circuit is closed already on the installed devices).

We check all the liners and fasteners, after which we proceed to set up.

Height adjustment

The very first thing to check on the front frame is its height. During installation, inaccuracies often occur when the switch is too far from the stars, or when it touches them. The mechanisms are imperfect and the purpose of the height adjustment is to properly adjust the frame (about 2-3 millimeters above the large star). After installation. check the distance by turning the system with the attached chain.

Rear derailleur

Initial checks on a rear bicycle derailleur begin with the derailleur mechanism. complex than the front, it can hide more problems in itself than can be corrected with a tweak:

  • The rooster is a special mount, and, being usually a separate part from the frame, the rooster is damaged by falls and even serious loads, therefore it is very important to check its parallelism to the frame and, in general, its integrity.
  • Recoil spring. its defects are often perceived as problems with the cable jacket, as they look the same: switching on the loosening of the cable becomes problematic. Springs are usually changed along with the entire device.
  • The cable feed is a secondary test, on many derailleurs, especially budget Shimano derailleurs, the cable runs into the rear derailleur from the back, creating a kind of loop. It is on it that damage usually appears, since this point is easily damaged when falling or driving on the grass.

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 do not show numbers on the shifter, but believe me the position of the indicator is at number 9. Which corresponds to the smallest star on the cassette.

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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 that are 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.

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, by 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.

assemble, derailleur, bike

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 presser foot rollers with the center of the largest sprocket. All this alignment takes place with the screw L.

Essentially, the H and L screws act as end stops for your derailleur, which keeps the chain from flying off 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).

Next, we again 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.

How to make a derailleur on a bike

A very common problem faced by cyclists is the rear derailleur not working properly. Today we will try to figure out how to set it up from scratch or adjust it if the settings are out of order.

This article is suitable for setting up all shimano, sram, campagnolo, microshift and other derailleurs, no matter how many speeds you have on your bike, ranging from 2 to 11 speed sprockets on the rear wheel.

  • Causes of fuzzy switch operation
  • Rear derailleur setting process
  • Configuration errors

Steering wheel switches

There are two types of steering wheel switches. lever and cylindrical. Lever are a small lever located on the left or right of the steering wheel, with which the cable is pulled.

Cylindrical switches are switches that mount with a rubber or plastic handle to the edge of the handlebars. Switching here occurs by turning the handle down or up, then pulling the cable and moving the chain to the desired sprocket located at the back. They guarantee high-quality and fast shifting without getting off the bike and while driving.

How To Replace And Install A Rear Bicycle Derailleur

Elimination of problems in the operation of the gearshift

  • Sometimes an excellent result is obtained by elementary cleaning and lubrication of cables, shirts, after such a procedure, it is much easier to switch speeds.
  • If the smoothness of gear shifting is lost when changing the front sprockets, then most likely the bike cock is bent. This detail is highly evidenced by obstacle impacts. The breakage is easy to identify by eye, carefully consider the position of the switches: the correct rollers are located vertically relative to each other.
  • Remove the cock from the vehicle and straighten on a hard surface, or use a specific tool to leave it in place. A special pointer will show how smoothly the cock is.
  • If the steering shifter breaks down, the cable tension is immediately released. Don’t look for expensive replacement parts. On a simple bike, gearshift speed and weight are less priority than the cheapness of replacement elements.

Adjusting the rear derailleur on a bicycle is necessary after repairs or replacement of any elements. Strict adherence to all instructions will help you quickly achieve the desired result. If the chain still jumps tightly between the sprockets or starts to spin, rotate the cable tension drum.

Setting up bike derailleurs (beginner’s guide)

So, let’s continue our series of articles for beginners. Recall that in previous articles we looked at how to take care of your bike and properly shift gears on the move. In this article, I would like to make a short guide to self-tuning or even complete customization of the bike after purchase.

Opinions on how to set up a bike and where to start differ, many say that you must first set up the front derailleur, and then the rear, others vice versa. The essence of this does not change, but it is really recommended to first adjust the rear derailleur in order to more correctly configure the front.

Bicycle Rear Derailleur Setting

First, we’ll look at the design of the switch itself:

On more modern switches there is also a switch tension adjustment screw, but we will not consider it, since it is generally not needed in setting.

Switching the rear derailleur to the smallest star

How To Install A Rear Derailleur | Mountain Bike Maintenance

Unscrew the rear derailleur cable clamp screw and loosen the cable

Install the chain on the front derailleur to the middle sprocket (click the left coin on the steering wheel)

We spin the pedals on the weight, if the flail falls off the stars, then it is necessary to tighten the screw marked H by 1-2 turns, if after that the flail is in place, but at the same time it tries to switch independently to the next gear. we unscrew this screw by 0.5-1 turnover

The essence of this method is that when the rear derailleur cable is unscrewed, use the screw H to make the rear derailleur and the smallest sprocket in front are absolutely on the same mowing line, this is easy to check, just look at the rear of the transmission from the side of the stars.

If everything is ok, then move on. we pull the cable by hand and tighten the bolt to fix the tension

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Try it. click the rear derailleur shift knob 1 speed up, if the switch was correct, we click further to the largest sprocket, if not, then pull the cable with the adjusting drum. We unscrew the drum by 1 turn, try if ok, continue to click on, if it does not switch another 1 turn.

So, we got to the largest star in the back, but when switching, 2 situations can arise:

a) the chain falls off behind a large sprocket. then it is necessary to tighten the adjusting screw L by 1-2 turns

b) it is not possible to switch to the largest star at the back, the shift knob does not click or the switch itself simply does not switch. then the bolt marked L should be unscrewed 1-2 turns.

That’s all we have set up the rear derailleur of the bike. All adjustments with bolts H and L are carried out slowly, you should unscrew / tighten no more than 1 turn at a time, maybe even 0.5 turn, in order to set the switch as correctly and quickly as possible. Let’s move on.

When adjusting the front derailleur, there are nuances that depend on the derailleur itself (foot width) and transmission (6/7/8 or more speeds). We take a look at the most popular Shimano Tourney FD-TX50 and Shimano Acera FD-M360 derailleurs.

Switching to the smallest star in the front and the largest star in the back.

Unscrew the front derailleur cable

We adjust the switch frame with the screw L so that when installing the switch, the inner part of its frame (the one that is closer to the bike, when viewed from above) does not touch the chain. tighten if the distance to the chain is more than 3 mm or unscrew if less.

After that, we pull the front derailleur cable, but not tightly, so that when you tighten the cable tension screw so that the cable is slightly relaxed (dangling in a horizontal plane by about 1-1.5 cm)

We switch to the middle star and start checking. we install the second star behind, that is, not the smallest one, but the next one. We check. if the chain touches the outer frame of the switch, then we stretch the cable, on the shift knob we have the same plastic bolt as on the rear derailleur, unscrew it 1-2 turns, so that the distance of the chain from the outer frame of the switch is 3-4 mm.

Moving on to setting the largest sprocket. switch the rear derailleur to the smallest sprocket and watch. If we switched without problems, then we do not turn anything, if it did not switch, that is, there was a click, but the switch did not switch, then we unscrew the screw H by 1-2 turns, if it switched and the chain slept, then we tighten this screw by 1-2 turns. We check further. the distance to the outer frame should be no more than 3 mm when turning on the smallest star from behind. If everything is ok, then you did everything perfectly.

The bike derailleur setup is complete and you can now proudly sit down and enjoy riding your iron horse. There are tons of setup videos, the best of all is at this link:

Ride with pleasure!

How to adjust the rear derailleur on a bike

Setting up the speed switch is not a tricky business, and anyone who knows a little about the mechanisms can do it.

To independently configure all the mechanisms and put them into action, you need to do the following:

  • you need to check if the switch itself is bent. This can be determined by looking at the tensioner. it should be parallel to the stars on the rear wheel. If it’s all about him, then you need to try to straighten it with pliers or other tools.
  • if everything is fine with the switch, then most likely the cock is to blame (this is the mount on which the switch is placed). Most often, it also bends, and it has to be straightened periodically, so that at the first breakdown it needs to be replaced.

If all of the above is done or in order, then you can proceed directly to the switch setting itself.

This should be done as follows:

  • put the switch on the highest speed (that is, on the smallest star)
  • we find two screws. H and L. Turn the screw H so that the roller on the switch moves one mark with a smaller star
  • put on the lowest speed (large sprocket), and rotate screw L until the roller is aligned with the large sprocket
  • again set to the highest speed, and pull the cable. In this case, you need to make sure that he got into the special prem. It should be pulled tighter!
  • check switching! If it switches very tightly, or does not switch at all, then you need to loosen the cable a little, or, on the contrary, pull it.
  • if everything works well, then we can assume that the job is done.

How to fine-tune the rear derailleur

The most important factor when adjusting a switch is accuracy. You can fine-tune it as described at the beginning of the article, but during implementation you need to pay special attention not only to the adjusting screws, but also to the entire mechanism as a whole.

Cables and shirts

The cables for the front derailleur differ from the derailleur on the rear in that they can be slightly shorter, or even slightly thinner. And shirts are also divided into three types, and each shirt has its own cable.

How to properly adjust the rear derailleur

To independently adjust the rear derailleur on a bicycle, you just need to strictly follow the step-by-step instructions from specialists in this process. So, follow all the steps:

  • Move the chain to the small sprocket with the right shifter.
  • Unscrew the fixing screw and release the cable.
  • Find the screw with the H mark. Use a screwdriver to adjust this screw so that the smallest star lies in the same plane with the rollers that are located in the foot (frame).
  • Pull the cable by hand and fix it with the screw.
  • Check the operation of the switch, and if it does not work correctly, the chain does not switch well to large stars, then you need to tighten the cable harder (either with the help of a drum or with a switch).
  • Move the chain to the largest sprocket available in the cassette.
  • Find the screw marked L and adjust it so that the tab (frame) and the sprocket are in the same plane. in this case, the crossover will not be able to get into the spokes of the front wheel.

Correct cycling gearshift setting

Modern bicycles equipped with a gear system allow you to move quickly and with minimal energy losses in any conditions: long climbs, rough terrain, roads with sharp turns that require constant changes in speed and gear ratio. This can also include driving against the wind, off-road, poor quality asphalt In general, the value of the transmission unit is simply colossal, especially on mountain bikes.

Despite the invaluable help, the transmission is great and requires frequent attention, care, and sometimes long and tedious fuss. One of the components that needs to be spent periodically is the shifting mechanism, which consists of front and rear derailleurs. At first glance, the arrangement of these parts seems complicated. In practice, setting up gear shifting is very simple.

Necessary terminology

To understand the process of self-adjusting the speed switch, you need to know the definition of some specific terms, otherwise it will be difficult to understand the instructions.

  • Speed ​​switch (crossover). This is a transmission element that is specifically responsible for gear shifting. If there is a rear crossover, then it also acts as a support for the tension of the bicycle chain. The crossover (back and front) can be described as follows: it is a parallelogram mechanism equipped with a powerful return spring, on which the frame is fixed. The rear derailleur has two rollers inside the frame. if the level of cable tension increases, then the frame shifts the chain to large stars, and if this cable tension decreases, then the chain is shifted towards small stars with the help of the frame. The mechanism of the front derailleur works in the same way.
  • Shifter. It is designed to switch speeds by changing the tension level of the cable. Most often, the shifter is located on the handlebars, but in some models of bicycles it can also be located on the lower tube of the frame triangle. Note:shifters and speed switches have a common connection on the steering wheel (this is provided by a cable) and are covered with a jacket.
  • Cassette. This is the name of the rear transmission unit, which consists of stars of different sizes (of different diameters and with a different number of teeth) and is installed on the rear hub drum. If the bike is old, then a ratchet is used instead of a drum in the rear hub.
  • Cock. It is a metal part that helps maintain the integrity of the frame and rear derailleur in the event that the vehicle has been hit. The rooster is always attached to the frame, and a cross-over is already attached to this metal part. When a blow occurs, it is this very cock that breaks, and the frame and the speed switch (crossover) remain intact.
  • System. This is the name of the front transmission unit, which consists of stars of different diameters and with a different number of teeth. These stars are fastened to each other and the connecting rods with special hollow bolts on the connecting rods, but you need to know that there are no hollow bolts in cheap bicycles. the stars and connecting rods are riveted to each other.
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Bicycle front derailleur

The transition to the setting of this mechanism is possible only when the rear derailleur is set. This feature is important to take into account before starting work. The figure shows the switch (round, black).

Leave the chain on the middle sprocket of the front block and place it on the large sprocket in the rear block. If chain friction is observed, re-engage adjuster L. To adjust stop H, the chain moves to the largest sprocket at the front and smallest at the back. The adjuster will help to position the chain in the optimal position without friction and excessive tension on the chain. At the end of the work, be sure to check the quality of its implementation.

Why is there a violation of gear shifting

To understand what action should be taken to adjust gear shifting, you need to understand what causes can lead to the problem in question. Experts identify several such predisposing factors:

  • deformation of the rooster;
  • stretching the cable;
  • deformation of the speed switch;
  • malfunctioning return spring.

Why bike speeds don’t shift well

Usually, the thought of needing to fix derailleur problems comes when the chain is shifting too hard between the sprockets, or the gears are not shifting at all. The problem comes suddenly, as an option, you can contact the master.

However, this issue can be resolved in the service in a couple of minutes, and the money will have to be paid in an hour. Maybe you should tinker yourself?

Before proceeding with the instructions for setting up the bike speed system, let’s determine why it does not work correctly:

  • Switches are damaged. A complete replacement is needed to solve the problem.
  • Deformed cock. protection of the rear derailleur. Usually it is advised to change, but once you can straighten.
  • Spring worn or stretched cable. Replacement required, switch setting.

Very often, all the components of the transmission are in good condition, and the gears are still poorly shifted. New parts, or small workpieces installed in a transmission unit are a common cause of poor chain sprocket running.

Setting switches at home

Now let’s figure out how to set up the speed system ourselves. Derailleurs on bicycles with multi-gear transmission are divided into front and rear. The latter are most vulnerable when riding in a variety of road conditions, the risk of damage is higher compared to the front ones, but the adjustment must be done at the very beginning. Obviously, the rear derailleur serves more stars, so it takes longer to set up.

Attention! If there is damage, and the tensioner is not parallel to the frame and cassette, then it will not be possible to correctly adjust the system!

First you need screws L and H. they are clearly visible, no need to look. Also includes a cable adjuster, tension and fixing screws.

  • H is used to align the roller with the small rear sprocket. By tightening the screw L, we set the roller on one straight line with the large rear sprocket.
  • Set the highest speed on the shifter.
  • Tension and fix the cable with the fixing bolt.
  • Large gears should be included without interference, otherwise, using the adjuster, the cable is slightly weakened. Additional tension will be needed if gears are poorly reset.

Actually, the adjustment itself is made, it remains to adjust the switching accuracy. This is especially true for systems with a large number of stars. To do this, the chain is installed on a large chainring at the back and a small one at the front. By tightening the tension screw, we achieve the optimal position of the roller. as close as possible to the cassette. The same must be done and vice versa: set the chain to the maximum sprocket in the front and the minimum sprocket at the back. The roller should not rub against the cassette, just be located next to it.

How to properly set up the switch in front:

  • Check device attachment.
  • At minimum speed, release the cable tension.
  • Use screw L to create a gap between the derailleur body and the chain (1 mm).
  • Secure the cable with the adjusting bolt.

The same should be done with the H-screw. The maximum speed must be set, and the gap with the chain must not exceed one millimeter.

How to Change Your Rear Derailleur. Replacing Your Bike‘s Rear Mech

Adjust the speeds on both derailleurs until the chain is free to swing from one chainring to the other. If it is difficult to walk, it is necessary to adjust the correct position of the cable using the adjusting bolt.

After all the manipulations, the entire system is checked. To do this, you need to ride a bike and try all the recommended gear ratios. Note that on mountain bikes, the transmission adjustment is a common periodic procedure, and if suddenly the transmission goes tight, we are not in a hurry to draw conclusions about the breakdown, but we do what is described above.

Do not think that a high-quality transmission does not need to adjust the shifting system. Yes, it may be necessary to do this less often for shimano components, but sooner or later you will still have to face.

We just saw an easy way to adjust the front and rear derailleurs. Is it really necessary? Adjustment of the shift mechanism is necessary for the transmission, like tires for a wheel. Timely assistance to the traffic node will not only solve current problems, but also prevent them in the future. Eliminate all inconveniences in time and ride with pleasure!