How to fix the rear derailleur on a bicycle

How the switches work

Using the handle and shifter, the cyclist activates the required speed. In a certain position of the handle, the cable is pulled. As a result of this tension, the frame is thrown onto larger sprockets; when the cable is loosened, it is not thrown onto small sprockets. As mentioned above, you can start setting up your bike from the rear derailleur. Procedure for adjusting the rear derailleur:

  • select the second star in the front block, and the smallest in the rear one and set the switch chain on them;
  • The bike’s rear derailleur system has two bolts that act as stops. One is abbreviated as H, and on the other. L. These two bolts are used to adjust the high and low gears on the sprockets. If during the adjustment process any extraneous sounds occur, you can get rid of them with the help of the latch;
  • check the tension of the cable and if the tension does not correspond to the required one, use the regulator located on the shifter;
  • Test the switching quality. If the switching occurs smoothly, no extraneous sounds are heard, then you did everything right.

Switching recommendations

Drive only at speeds that will not cause the chain to tilt too much. For example, you cannot set the speed to 1/8, 1/10, 3/1 (the first number is forward gear, the second is reverse), and so on. For the smallest front chainring, you can turn on 1–4 speeds at the rear, for the middle. 3–7, for the largest. 7. If you nevertheless put an incompatible gear, there will be a risk of chain jamming and spinning, as well as an increase in its wear rate.

On a speed bike, fast gear changes are very important, especially if you are competing. Transmission repairs should be carried out before the race, and then after, as aggressive driving can cause the shift adjustment to be out of order. If you do full maintenance of your bike at least once a season, it will serve you for a very long time.!

Tools:

The tools you may need are a Phillips screwdriver and possibly a 10 or 8 hex key or wrench depending on the switch. It is also very convenient to carry out work on a special bike rack, but you can also cope without it.

Bicycle front derailleur

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

rear, derailleur, bicycle

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.

Rear derailleur

Make sure the cock is level first. If it is still bent, you can contact the service to straighten it, or try it yourself. Alternatively, you can simply replace it. For 2016, for roosters are only about 300-900 rubles. Do not even try to tune the derailleur with a bent cock, as the gear setting on the bike in this case will not work for you.!

Some firms produce the so-called cock guard, which is attached to the frame. Do not buy it under any circumstances! A rooster is a consumable component that can and should be replaced if it breaks. When hitting this very protection, the cock will remain intact, but the frame may crack. The frame is harder and more expensive to change.

When you are convinced that the rooster and the cable are in good condition, you can proceed to the actual setting.

Place the chain on the largest chainring in the front and the smallest in the back.

Unscrew the bolt that holds the rear crossover cable.

By rotating the bolt with the inscription “H” you need to make sure that the switch rollers lie in the same plane with the desired sprocket.

Then lightly stretch the cable and tighten the bolt holding it. Over-tensioning the cable will make the crossover difficult to work.

Shift the speed to the lowest (i.e. the largest star in the back and smallest in the front).

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Rotate screw “L” until the derailleur rollers line up against the large sprocket.

Check if gear changes are good.

If shifting is not correct, use the thumbscrew on the shifter, which changes the cable tension.

Now that you have set up the rear derailleur, you are ready to adjust the front.

How to fix a derailleur on a bicycle

How to fix defects

The speed switch will work perfectly and the bike itself will be with a new (or not very old) cable, with absolutely intact shirts (and not dry!) ​​And not deformed (or in a small volume) stars and chain.

Destroyed Derailleur/Bent Twisted Hanger. I Can Fix This!

If the cable is just stretched, then you just need to pull it up. But if the cable breaks, then you cannot do without replacing this element. The process of replacing the cable is not difficult, the main thing is to strictly adhere to the recommendations of the specialists:

  • unscrew the cable fixing screw, which is located on the cross-over;
  • pull the cable out of the shirts;
  • if necessary, disassemble the shifter and pull the cable out of it;
  • a new cable must be inserted into a special groove in the shifter, and it is the metal tip of the cable that must enter into the groove;
  • lubricate the entire cable with a special grease, you do not need to spare the consumable;
  • pass the cable through the shirts;
  • there are special grooves on the frame, into which shirts are tucked;
  • fasten the cable with a screw on the front end.

In case of poor gear shifting, pay attention to the return spring. it must be clean and lubricated. To achieve this, you just need to rinse the spring under running water, dry it completely and lubricate it thoroughly.

If the frame of the rear derailleur is crooked, then this can only mean one thing. the cock is bent. If this is not critical, then you can correct the cock with your hands. you need to take the rear switch in your hand, which is fixed on the cock, and hold the frame with the other hand. Slowly pull out the problematic transmission element (cock) until relatively even setting.

Note: this “repair” of the cock is a temporary solution to the problem of shifting gears. The fact is that the rooster is a consumable that needs to be changed on time, and not constantly repaired / pulled.

In some cases, the bike owner pays attention to a deformed rear derailleur (the front derailleur rarely suffers on impact). it can also be returned to its original position with the help of hands. But if the rear derailleur is deformed too much, then it is advisable to replace it.

Note: After performing specific manipulations to repair bent / deformed parts, you should not use the bike for too long. this may end in a fall, another breakdown at the most inopportune moments. And in some cases, such carelessness can lead to a traffic accident.!

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 experts 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 more (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 cross-over will not be able to get into the spokes of the front wheel.

How to fix bike speeds

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.

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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!

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 movement against the wind, 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.

Derailleur repair for beginners

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.

Why is there a violation of speed switching

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.

Bicycle Rear Derailleur Setting

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.

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 (cross-over). 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 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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Causes of breakdowns

If the bike does not change gears, it is necessary to find out the cause of the malfunction. This kind of problem can be associated with various factors:

  • Improper condition of cables and shirts. For effective gear shifting, these parts must be intact and clean. If there is contamination, they must be removed. If the cable is damaged due to wear (fluff or torn), it must be replaced with a new one.
  • Lack of lubrication. If there are no dirt and defects, but the bike does not shift gears well, the cable can be treated with Teflon grease. This will ensure proper glide. It is strictly forbidden to lubricate parts with thick compounds (like grease).
  • Deformation of the bicycle cock. The rear derailleur device may malfunction due to bracket problems. He could easily bend while transporting the bike. This nuisance is especially relevant in the case of purchasing a new bicycle.
  • Backlash between parts. During prolonged operation, the rear derailleur may have large gaps between the cable and other structural elements. Free wheeling is not always a bad thing, but if the speed does not switch immediately or it is difficult for the driver to adjust the mode he needs, then the backlash has increased significantly and the switch needs to be reconfigured.

Timely maintenance of your bike is essential to avoid breakage. Any changes in its work can signal possible problems. This does not necessarily indicate defects or wear. The gearshift mechanism may not work correctly due to commonplace beginners’ mistakes. incorrect transmission settings or untimely cleaning of parts.

To avoid breaking the speed switch on your bike, it is also important to be able to use it correctly. Firstly, you can change the speed mode only while driving. if the pedals do not rotate, then an attempt to move the chain can lead to a breakdown of the entire structure. Secondly, this should be done only when driving on a flat surface and not uphill. If there is a climb ahead, you must change the speed in advance. Thirdly, for a smooth shifting, you should relieve the load on the pedal (especially if you have a front derailleur on your bike).

The speed mode must be changed sequentially one after the other. without skipping over several.

Deformation of the bicycle cock
Broken cable
Backlash between parts
Lack of lubrication