Bicycle gearshift setting rear

Rear derailleur setting

It is convenient to lubricate, adjust and repair chain drive units with the rear wheel raised. To do this, you can tilt the bike, leaning on the side stand, hang the bike on hooks or an ironing board, ask a friend for help. A rear wheel stand will help out well in this situation.

  • clean the derailleur and sprocket cassette well;
  • place the chain at the front on the middle sprocket and at the back on the smallest sprocket.

The rear spreader must be cleaned to properly set up. Namely: clean the tensioner rollers from dirty grease, remove the blades of grass and sticks from the sprocket cassette, wash and lubricate the chain. Even after this simple work, the switch starts to work much better.

  • screw in the tension screws on the rear spreader and at the shifter all the way;
  • pull the cable out of the retaining screw.

It is not necessary to completely remove the cable from the bike, but it will not hurt to inspect it for damage and lubricate it.

Setting the travel limit to the smallest sprocket: crouch at the back of the bike and turn the adjusting screw H, set the thrower so that its rollers and the smallest sprocket in the cassette are on the same straight mowing line.

There is one trick here: if the spreader is no longer new, and it staggers, then you can adjust it more or less accurately only by placing the frame not along a straight mowing line, but literally moving a hair to the right, away from the wheel.

bicycle, gearshift, setting, rear

If the setting is done correctly, then when the wheel rotates, the chain does not try to jump to the side and works silently.

  • we fix the cable with a mounting bolt, pulling the cable not with pliers, but by hand;
  • we tighten the cable by rotating the hollow screw with a drum, so that the spreader easily switches from one sprocket to another and back with one click and pressing the shifter.

It is enough to adjust the transition only between two adjacent stars, and the shift will be adjusted on all the sprockets of the cassette. This is the advantage of the index gear change system.

If a groove is provided for the cable in the clamp, then make sure that it hits exactly in it, and does not squeeze, being fixed incorrectly.

Setting the travel limit to the largest sprocket:

  • we loosen the adjusting screw L so that it does not interfere with the movement of the spreader;
  • turning the pedals, we throw the chain to the largest sprocket at the back;
  • by turning the adjusting screw L, align the spreader in the position when its rollers and the largest sprocket of the cassette are exactly on the same mowing line.

Again, if your bike has a knobby derailleur, then it is advisable to move its frame slightly away from the straight mowing line, but towards the wheel when adjusting. Sometimes this is just a little bit is not enough for the wobbly derailleur to throw the chain onto the largest sprocket in the back.

  • we transfer the chain to the smallest sprocket in the front and the largest in the back;
  • if, when the chain rotates, the upper tensioner roller touches the sprocket in the cassette, then tighten the chain tension screw. It is necessary to set the gap between them, approximately equal to 5 mm;
  • move the chain to the largest sprocket in the front and the smallest at the back and check the chain tension in this position.

Steering wheel switches

If the shifter on the handlebars breaks, it will not be difficult to understand this, since the cable tension will immediately weaken, or it will simply stop pulling. Chasing expensive Sram, Shimano components in the hope that they will not work better is not worth it. For an ordinary inexpensive bike, the speed of gear changes and the weight of components are not as important as the maintainability and cheapness of replacement parts.

about setting the rear derailleur in a short

bicycle, gearshift, setting, rear

How to adjust the bike’s rear derailleur

It must be said right off the bat that the hardest thing to tune is old, worn out switches. The cheapest spreaders made of low quality material wear out very quickly. After years of operation, so much material is produced in the joints of their mechanisms that backlashes are already becoming noticeable. Large wobbles of the rear derailleur will prevent you from adjusting to at least remove loud crackling when driving.

Adjusting the gearshift paddles is not a difficult job to be contacted by a mechanic. You will not be able to break the gearshift mechanism, the index system for changing speeds is the simplest and most reliable of all.

Chain tensioner rollers

The small sprockets on the switch frame should also be cleaned and lubricated at least once a year. Having outlived their own, and even without a share of attention, the rollers always jam, and the chain on them often simply rubs, bouncing and flying off the rear sprockets.

As for the material for making the rollers, that is, a carbon coating on top, and ceramic bearings inside. But to save the household budget, it makes no sense to buy expensive toys, since all common plastic wheels will last longer than the switch itself, of course, with simple maintenance.

Rear Derailleur Adjustment

Chains and sprockets

Sometimes the cause of a problematic gear change is already the extreme wear of the chain drive. Long driving at prohibited speed combinations leads to increased lateral wear of the chain and sprockets. Do not ride in positions where the chain is very skewed: on the smallest sprocket in the front and rear and on the largest front and rear sprocket.

There are times when the new rear sprocket cassette is skewed onto the rear wheel hub, as many people buy the cheapest bike parts. And often, in order to eliminate the wobbling of the sprocket cassette, it is enough to adjust it by removing one or two adjusting rings inside the ratchet mechanism.

Adjusting screws on the switch

Despite the variety of parallelogram switches sold, the principle of their operation is the same, and therefore, they have a similar design. Usually they all have 5 adjusting elements:

  • Embedded bolt with nut for fastening the cable.
  • Hollow screw with cable tension drum.
  • Thrower travel stop screw to largest sprocket. denoted by letter L.
  • Thrower travel stop screw to smallest sprocket. marked with H.
  • Chain tension screw.

Some inexpensive derailleurs may not have a cable tension drum and chain tension screw. But there is an adjusting drum on the steering wheel shifters. So you can adjust the tension of the cable directly in motion, without forgetting to throw the chain onto the smallest sprocket.

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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 on the “number” 9. Which corresponds to the smallest star on the cassette.

When adjusting the rear derailleur on the sprockets (front) the chain is best positioned 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 we 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 on 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.

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”.

On the shifter, the indicator for switching the speed to number 1, if there are no numbers to 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.


Try to visually diagnose the condition of the gear selector parts. After all, you can spend hours studying theory and trying to repair, and in the end find out that the part cannot be restored. To do this, stand behind the bike and try to make sure that the derailleur and its bracket (cock) are on the same mowing line and that there are no noticeable distortions or significant deformations on them. The chain that connects these elements can help you a little with this, but it should also be in satisfactory technical condition. well lubricated and with acceptable wear, since some difficulties when switching speeds may also arise due to its unsatisfactory functioning or the wrong type.

Similarly, with the gear shift cable. if it is rusty and constantly wedges in the casing, then there can be no talk of any reliability or ease of use. However, this situation is easier to fix, just add graphite grease to it in the required amount, and perhaps the Shimano rear derailleur adjustment will advance faster.

Tensioner and its adjustment

This adjusting screw is used very infrequently as it helps to adjust the position of the upper pulley in relation to the cassette along which the chain travels. If it is not twisted, then the above parts can touch each other and cause a lot of inconvenience. However, this situation is very rare, since this unit is fastened reliably enough and there is no backlash in it, which would contribute to its weakening.

Shimano’s rear derailleur setup is very accessible, however it may seem a bit overwhelming for beginners. Although this mechanism is simple in design, adjusting it requires meticulous attitude and patience. Haste is inappropriate here, especially if the work is being done for the first time.

Special cases and their resolution

If the chain slips when pedaling with a little effort, it is most likely stretched along its length and needs to be replaced. When used in this form, it is possible to harm not only the stars of the system, but also the cassette, which will render them unusable. A worn chain crushes or pits their teeth, making these shifting elements unusable.

When changing speeds, make sure that the chain runs smoothly. Although its location is fixed if you have a Shimano Deore or higher class rear derailleur installed, these cases are not uncommon for people using more common attachments. This malfunction leads to accelerated wear of the system elements and the chain, therefore it must be taken very seriously.

If the gear shift is suddenly disrupted and no longer works, then, most likely, there is a problem with the cable. Either it broke off, or it was not securely fastened with a fixing bolt.

If you have a Shimano attachment that has already been set to the rear derailleur and is not functioning properly, you need to make sure the cable runs freely in your shirt. If it has cracks or loose winding spots, it must be replaced. Similar problems can also arise if the bike cock has been bent.

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Causes of failure of the rear derailleur on a bicycle

Before you start adjusting the rear derailleur on your bike, you need to see if it might also be worth adjusting the front derailleur, and also identify the source of the problem:

  • damage to the cable or lack of lubrication on it;
  • deformation of the rear spreader fastener. rooster;
  • development of a chain or sprocket system on the rear wheel;
  • wedge of chain tension rollers;
  • malfunctions in the shifter responsible for changing speeds on the steering device.

Tension adjusting screw (“B-tension”)

Modern switches have two levers. The first one (“A-pivot”) is located below and provides the elevation of the gearshift frame upward, to the small sprocket. The second (“B-pivot”) moves the derailleur frame in the opposite direction to the large sprocket. The spring tension on these levers must be balanced to ensure smooth shifting.

Most rear derailleurs have a screw (Shimano terminology “B-tension adjuster”) to adjust the spring tension of lever “B”. Due to the adjustment of this screw, the height of the guide roller is adjusted (the angle of inclination of the chain from this roller to the sprocket).

To tune, slide the chain onto the large sprocket at the back. By unscrewing the adjusting screw counterclockwise, the roller rises up (closer to the sprocket). This increases the tension of the chain, and the accuracy of gear shifting increases. Be careful, the roller should not touch the star, leave a gap of 5 mm.

Adjustment position

Changes to limit the movement of the bike chain are made with special screws. Typically, the top derailleur is responsible for the offset that the rear derailleur (Shimano Tourney and other budget series) receives when upshifting, while the downshift is directed downward. If the chain slips through the largest sprocket, then it is the position of the gear adjustment with their increase that needs to be changed. Similar actions are performed when the speeds are reduced. However, every cyclist needs to know that if the rear derailleur was bent and then aligned, then it must be re-adjusted, as it changes its position.

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 marked “H”. Use a screwdriver to adjust this screw so that the smallest star lies in the same plane with the rollers, which 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.

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.
bicycle, gearshift, setting, rear

Why bike speeds don’t shift well

Usually, the thought of having 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?

How to Adjust Rear Derailleur Cable Tension

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 parts with little wear and tear, installed in a transmission unit are a common cause of poor chain sprocket running.

Adjusting the front derailleur

  • We put the speed switch in the following ratio: the smallest star in the front and the largest in the back;
  • We unscrew the cable;
  • Using the screw of the limiter for low gears, we adjust the position of the frame, it should be at a distance of no more than 3 mm from the chain;
  • Stretch the front derailleur cable slightly;
  • Switch the speed to the middle sprocket and check if the chain is touching the outer frame. If it touches, it is necessary to tighten the cable more;
  • We put the derailleur on the smallest sprocket and check how easy it is to change gears. If the switch does not work, adjust the high gear limiter screw.
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What to do if you can’t adjust the bike’s rear derailleur

There are several methods for solving this issue. But if the standard tuning instruction did not work, to tune the rear derailleur you need to:

  • dismantle the chain, remove the cable;
  • move the switch to the chain position to the smallest star;
  • use adjusting bolts (this way you can tighten the cable);
  • set the adjusting bolt H to the extreme position;
  • move the part called the parallelogram to the big star and adjust the position of the bolt L.

How to Adjust the Rear Derailleur for Crisp Shifting

The regulator is fixed with bolts. It must be set to the extreme position. After that, the chain must be displaced in this order: the front cassette is the largest star in diameter, the rear one, on the contrary, is the smallest.

How to adjust the front derailleur

There are also clear and simple step-by-step instructions for adjusting the front derailleur:

  • Shifting the chain to a smaller star.
  • Unscrew the fixing screw and release the cable.
  • We find the screw marked “L”, with its help we adjust the position of the frame so that the chain is between the plates of the frame, but at the same time does not touch them.
  • We stretch the cable, fix it with a screw.
  • Now we move the chain in the cassette to a smaller sprocket. it is convenient to do this using the rear derailleur.
  • With the front derailleur, move the chain to the middle sprocket and look. if the chain on the second one touches the outer side of the frame everywhere, then you need to increase the cable tension using the drum located on the left shifter.
  • We switch the gear to the largest sprocket in the cassette and check. if the chain touches the walls of the frame, you need to move the last element so that the chain is in the middle. This manipulation can be done using the screw marked “H”.

Rear derailleur

The gear selector is an important part of a multi-speed bike. Thanks to this component, it becomes possible to move in extreme conditions, which include upwind movement, ascents, poor road quality. The transmission unit must cope with all these problems. The quality of the ride and the safety of the cyclist depend on the smooth operation of the speed switch. This skill is very useful, and every bike owner should learn how to independently adjust the gear shifter. Each cyclist can make adjustments to the bike’s gear shifters on their own. You need to study the theory in detail by reading the instructions, or using the advice of experienced bike owners.

Before setting the derailleur, the rear derailleur must be adjusted. Placing the bike in the correct position (wheels up) will greatly facilitate the entire adjustment process. So, all the necessary details will be in plain sight, and it will be much easier to get to them.

Reasons for poor gear shifting:

  • physical defects of the switch parts;
  • contamination of parts. To prevent this from happening, the components of the transmission unit must be periodically cleaned of dirt, dust and old grease;
  • worn out cable with elements of damage. Such a part requires replacement;
  • damage to the cock.

If you observe damage, deformation and wear of the constituent parts, they must be replaced as they are practically irreparable.

If all parts are OK, adjust the switch. What is the speed selector made of? The components of the speed switch are as follows:

  • The handle for shifting the speeds, located on the steering wheel;
  • A shifter that attaches to the handlebars near the handles. Handles and a cable are attached to the shifter. It is with the participation of the cable that the impulse is transmitted from the shifter to the stars;
  • Cassette, which includes stars of different sizes;
  • front fixing mount;
  • rear derailleur, whose main function is to transfer the chain to the necessary sprockets.

Tension adjusting screw (“B-tension”)

Modern switches have two levers. The first one (“A-pivot”) is located below and provides the elevation of the gearshift frame up to the small sprocket. The second (“B-pivot”) moves the selector frame in the opposite direction to the large sprocket. The spring tension on these levers must be balanced to ensure smooth shifting.

Most rear derailleurs have a screw (Shimano terminology “B-tension adjuster”) to adjust the spring tension of the “B” lever. Due to the adjustment of this screw, the height of the guide roller is adjusted (the angle of inclination of the chain from this roller to the sprocket).

To tune, slide the chain onto the large sprocket at the back. By unscrewing the adjusting screw counterclockwise, the roller rises up (closer to the sprocket). This increases the tension of the chain, and the accuracy of gear shifting increases. Be careful, the roller should not touch the star, leave a gap of 5 mm.

Principles of fine-tuning the speed selector

If the chain decelerates to a large sprocket, the cable is loose. turn the adjusting drum counterclockwise.

  • To adjust the switching to small sprockets, you need to loosen the cable;

If the chain decelerates to the small sprocket, the cable is weak. turn the adjusting drum clockwise.

If the reverse gear shifting on one chainring is normal, and on the other it is bad, most likely the cock will be bent.

Fine tuning the bike’s rear derailleur

If the speed switch is set correctly, then during its operation you will have to adjust it only slightly, due to stretching or replacement of the cable.

Adjustment is made with an adjusting drum located on the shifter, on the speed switch itself (for mountain bikes) or on the upper part of the lower frame tube, near the shirt stop (for road bikes) of the cable on some switches there may be two drums. Adjustment can be done with any adjusting drum, it makes no difference which one to use.

Before tuning, shift the shifter to the highest gear (small sprocket), make sure the shift lever is in its full position.

Next, switch the shifter to the next speed and pedal forward. The chain should move to the next sprocket. If the chain does not cross, then the cable is not tight, turn the adjusting drum counterclockwise and the cable will be taut. Turn the drum half a turn and try changing the speed again. Be careful, if you overtighten the drum, the entire shift chain can shift, as a result, the gears will shift normally, but there will be malfunctions in the extreme positions. Therefore, first of all set up the first two switching steps.

Campagnolo rear derailleurs

Since 2001, all Campagnolo derailleur models have the A-tension adjustment for the lever spring. In fact, this setting is the exact opposite of the above “B-tension adjustment”: loosening the spring of lever “A” achieves the same result as tightening the spring of lever “B”.