How to adjust the gearshift mechanism on a bicycle

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 conditions, 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 component that needs to be taken up 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.

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.

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.

How To Adjust Your Front Derailleur

  • 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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Adjusting the front derailleur of the bike. How to setup?

Adjustment, setting the front derailleur is not difficult if you do everything carefully and consistently, but first you need to adjust the rear derailleur, and then proceed to the front.

The whole process can be divided into three stages:

4) Key for 9 (in some cases, you need a 4-5 hexagon);

5) Cable and cable jacket (if yours are in poor condition);

First, check the cable and the cable jacket (to do this, loosen the tension cable and remove it from the jacket), make sure that the cable is not unraveled anywhere, the cable jacket is not “wrinkled”. If there are no kinks and unweaving, and the cable still moves tightly in the shirt, clean it from dirt, sand and lubricate.

Next, wash and clean the front derailleur, wipe and dry it well, and then lubricate all moving parts.

Twist the thumbscrew, which is located on the shift coins, almost to the very end (leave a couple of turns for adjustment). At this stage of preparation is over.

The second step is setting up the front derailleur.

Position the derailleur so that if you were looking at it from above, the derailleur frame is parallel to the chainrings. (to adjust the height and angle of the switch, loosen the clamping bolt)

In order to adjust the height, place the chain on a large sprocket, the gap between the frame and the large sprocket should be 2-3 mm. The smaller this gap, the better the switching.

Next, you should adjust the “blockage of the chain” (so that the chain does not fall when switching to lower and higher gears)

If you look at the switch from above, you can see two adjusting screws H.High (high) and L.Low (low). these screws are responsible for adjusting the “chain blockage”.

Place the chain on the small sprocket in the front and the large sprocket in the back.

adjust, gearshift, mechanism, bicycle

Begin to rotate the L.Low screw (low) until the chain is as close to the inner plate as possible, but make sure that the chain does not hit the frame when pedaling. Next, pull the cable with pliers and tighten the cable fastening screw.

Now you need to do the same with the H.High screw. We put the chain on the large star in the front and on the small back. Turn the screw H (High) until the chain is as close to the outer plate as possible, but so that when pedaling the chain does not touch the frame.

Now you need to check how the switch works by rotating the pedals (put the bike on a stand or hang the rear wheel), step by step change gears in both directions. If it does not switch well from large stars to small ones, it is necessary to loosen the cable by rotating the “lamb” on the coins, clockwise, and if it does not rise well from small to large stars, counterclockwise.

Stage three. checking the front derailleur.

After we have tested the derailleur on the weight, we need to do it under load, sit on the bike and ride, changing gears. The front derailleur should work smoothly and clearly, the chain should not rub against the frame

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?

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.

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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 may 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.

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”.

How to adjust the speed switch on a bike

It often happens that either the speeds on the bike are not switched clearly, or some new transmission elements have been installed. In this case, you will need to adjust the speed switch and it is quite possible to do this work on your own, without contacting specialized workshops.

External switching mechanism

This type of derailleur is used on most multi-speed bikes, from city bikes (like the Forward Dortmund 2.0) to mountain bikes (like the Forward Agris 27.5 3.0 disc). Gear shifting is carried out using the front and rear derailleurs.

adjust, gearshift, mechanism, bicycle

Front derailleur The front derailleur transfers the chain between the chainrings. The derailleur design has a moving frame within which the bicycle chain runs. When shifting gears with a shifter, the frame moves and becomes above the desired star, which ensures the movement of the chain to this star.

Rear derailleur The rear derailleur is a spring-return mechanism that moves a frame (or foot) with rollers between them within the transverse axis.

How to Adjust a Front Derailleur

Advantages of external switches: simple design low weight low price high number of gears

Disadvantages of external derailleurs:. highly susceptible to unfavorable external factors. need for adjustment and maintenance. risk of breakage when the bike falls. it is impossible to change gears if the bike is stationary

Rear derailleur setting

So, you have no transmission defects, all parts are relatively new (or completely new). And now you need to set up a clear gear shifting.

  • Use the right shifter that acts on the rear derailleur to move the chain to the smaller sprocket.
  • Release the cable by unscrewing the fixing screw.
  • Locate the screw marked “H”. Using a screwdriver, adjust the position of the switch with this screw so that the smallest star lies on the same plane with the rollers (stars) located in the tab.
  • Pull the cable by hand and secure with the fixing screw.
  • Check the operation of the speed switch. If the chain does not shift well to large stars, tighten the cable more tightly using the drum on the shifter, or on the switch (not available on all switches, it is located at the point of contact between the cable jacket and the switch).
  • Move the chain to the largest sprocket in the cassette.
  • Using the screw marked “L”, adjust the position of the cross-over so that the star and the foot are in the same plane, and the cross-over does not have the opportunity to “climb” into the knitting needles.

Internal switching mechanism

City bikes often use an internal gearshift mechanism that is hidden inside the rear planetary hub (for example, the new Forward Surf 2.0 cruiser). Planetary hub bikes have only one chainring and one sprocket. The number of speeds / gears of the planetary bushings is usually from 3 to 7. The planetary hub has a rather complex internal structure.

Pluses of planetary bushings: they withstand adverse weather and road conditions well, since the mechanism and all its parts are enclosed in a case and, as a result, are reliable and durable; you can switch speeds without pedaling.

Cons of planetary bushings:. heavy weight;. very difficult repairs, impossible in field conditions.

What is gear shifting

The essence of switching speeds is to drag the chain from one star to another. Various combinations of front and rear sprockets allow you to regulate the cyclist’s load. But first, let’s turn to the bike drivetrain.

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The transmission is all the parts and assemblies of the bicycle that provide the transfer of energy to the rotational movement of the rear wheel. The transmission consists of a carriage, a system of connecting rods, a chain, sprockets or cassette (or ratchet), front and rear derailleurs, as well as shifters (they are also sometimes called shifters).

Gear shifting occurs through the shifters located on the steering wheel. Using the rear derailleur shifter, located on the right handlebar, the chain is thrown between the rear sprockets, and using the front derailleur shifter (it is on the left on the steering wheel) between the front sprockets.

Most multi-speed bikes have three drive sprockets and six to eight driven sprockets. The fore stars are counted from small to large, and the rear stars, on the contrary, from large to small.

Basic conditions

To make gear shifting on a bicycle as comfortable as possible, it is not enough to take into account the degree of cross-country ability. The main criterion for choosing a gear is the cadence, which ideally should be 80-110 revolutions per minute. Only at a given rotational speed, the ride will always be comfortable and not too tiring, therefore, it is undesirable to start immediately at high speeds.

To extend the life of your bike’s drivetrain, remember that the main working sprocket at the front is the middle sprocket, as it prevents the chain from skewing significantly while driving. Any throwing of the chain over the sprockets is completely controlled by the cyclist. In this case, the correct algorithm for paired operation, described in the example above, must be observed.

Combined system

It makes no sense to describe it in detail, since such a mechanism has collected in itself all the disadvantages of both of the above structures. You can only meet it on city bikes, and it is a hybrid of a hub and a conventional exterior design.

Internal switching

This mechanism is rarely found on mountain riding models, but is often applicable to city bikes. It is based on the operation of the planetary hub, which is located at the back and contains the entire mechanism for shifting inside it. Thanks to this design, on the outer body of the bike, you can see only one chainring in front and one in the back. The number of speeds of this design is also quite large. In addition, a brake mechanism is mounted in the structure.

Pros and cons of an external system

Among the positive aspects of the design under consideration, many distinguish simplicity, low cost, compact dimensions and, with all this, a large number of shifted gears. Of course, external gear shifting on a bicycle has no less cons.

  • high probability of breakage if dropped;
  • switching only when driving;
  • frequent chain wear;
  • high degree of influence of external factors on work.

Front external flip mechanism

It is a structure with a moving frame inside that passes the chain through itself. Thus, when changing gears on a bicycle, along with the movement of the frame itself, the chain also moves to the desired sprocket.

The principle of the mechanism. nevertheless, it is not its only parameter when choosing, since such designs can also differ noticeably from each other in such characteristics as:

  • method of attachment to the body;
  • attachment angle relative to the bike body;
  • cable attachment option.

In this case, the bike’s gearshift cable can go into the derailleur from above, from below. It is also possible to use both options. The second parameter must be selected with special attention in order to ensure the most correct operation of the mechanism, and the structure itself can be fastened with clamps or carriages. In any case, the effective operation of the mechanism is ensured only without a direct strong load on it at the very moment of switching.

Rules for cycling with gear shifting

First of all, this is a careful handling of the entire mechanism. The chain must not be too skewed during operation and must not have a minimum rotating load during shifting. In addition, any changeover should be done gradually. You should not “jump” immediately from the first to the last gear, so it is better to switch in advance before driving up the mountain.

Cycling Gear Shifting: How to Set Up?

In our country, you can meet a huge number of people who are fond of cycling. All modern bicycle models are already equipped with a gearshift system. Such a mechanism is simply necessary for a comfortable ride in any road conditions. Bicycle drivetrains come in several flavors today, each based on a specific job. To choose the most convenient option for yourself, you should figure out what they are, how they differ and whether it is possible to independently adjust the gear change on a bicycle.