How do I solve this circuit 2

Adjusting the bicycle gearshift: How to adjust the rear derailleur & front derailleur

Does it crash when you want to shift from one gear to the other while cycling? In the fifth part of his bike repair series, Bergzeit bicycle expert Flo Glott explains how to set a misaligned gear shift correctly - so that the gears slip again with a derailleur.

There is nothing that makes a mountain biker, racing cyclist or touring biker more incandescent than a chain that cannot decide which sprocket and which chainring it comes to rest on. In the following steps you will learn how to correctly adjust the rear derailleur and derailleur of your bike.

Adjusting the circuit - a quick guide

  1. Clean and check the rear derailleur.

  2. Adjusting the rear derailleur:

    1. Adjust the lower end stop of the rear derailleur: Set the gears to the largest chainring at the front and to the smallest sprocket at the rear - loosen the shift cable with an Allen key - place the derailleur rollers parallel to the smallest sprocket (screw H)
    2. Adjust the upper end stop of the rear derailleur: Shift to the smallest chainring at the front - push the rear derailleur towards the largest sprocket with your fingers - the rear derailleur roller should align with the largest sprocket (screw L).
    3. Angle adjustment: Setting the smallest chainring / largest sprocket - adjust the pre-tensioning spring with B-screw and thus adjust the height of the upper pulley - the distance between the largest pulley and pulley should be approx. 1 to 1.5 chain links.
    4. Tension of the shift cable: Place the chain on the large chainring - screw in the adjusting screw for the tension on the gearshift lever or on the rear derailleur almost all the way - retighten the gearshift cable and screw it tight to the rear derailleur.
    5. Adjustment of tension: Shift to the middle chainring - shift through gears individually - if necessary, increase or relieve tension a little.
  3. Adjustment of the front derailleur:

    1. Set the correct height of the derailleur: The distance between the guide plate and the teeth of the large chainring should be 1 to 3 millimeters.
    2. Adjust the lower limit stop of the derailleur: Chain on the smallest chainring - loosen the shift cable - adjust the L-screw until the chain just no longer touches the guide plate.
    3. Adjust the upper limit stop of the derailleur: Place the chain on the largest chainring and the smallest sprocket - adjust with the H-screw so that the chain no longer touches the guide plate.
    4. Adjust tension: Place the chain on the middle leaf and the largest sprocket - change the tension until the chain no longer rubs against the inside of the guide plate.

In the following you will find detailed instructions for setting up your bike gears and the derailleur.

Preparation: clean & check in advance

Before starting the adjustment yourself, you should first keep an eye on your MTB or racing bike itself, as well as on the shift cables and the chain.

  • Cleanliness: The bike - especially the chain, rear derailleur, front derailleur, cassette and chainrings - shouldn't be too dirty. It is best to clean your bike beforehand with a cleaner, such as the Muc Off Bike Cleaner. Simply spray on, let it take effect and rinse off with water. For the chain, rear derailleur and other heavily soiled parts, it's best to use a toothbrush.
  • Chain: The chain should not be too worn out. This can easily be checked with a wear gauge (for example from Rohloff). Due to the stress of biking, the chain is stressed over time and a little longer. Therefore it should be renewed regularly. The change intervals are around 1,000 to 1,500 kilometers.
  • Shift cables and shift housings: Special attention should be paid to the shift cables and outer sheaths. The covers must not be damaged or even kinked. The course of the train should also not have curves that are too tight. Otherwise the shift cables cannot run properly and you will never get the gear shift properly adjusted. Especially if the shift cable already shows signs of oxidation, the cover and cable must always be replaced. Regular lubrication of the cables extends the service life, but you should change them regularly. Like you Shift cables are greasy, you can find out here: Make your mountain bike winterproof - in 5 steps.

Set the circuit in 6 steps

When the bike is clean and all parts have been checked or replaced, you can start. We'll show you the individual steps on a Shimano rear derailleur. With other drives or manufacturers, such as Sram, the functionality is similar.

A. Adjustment of the rear derailleur

1. Set the lower end stop of the rear derailleur

First you switch to the large chainring in front and the smallest sprocket in the back. If you have a single drive, you can of course neglect the information on large or small chainrings in the following steps. Then you loosen the shift cable with an Allen key. Now the pulley wheels should be exactly parallel in a line with the smallest pinion. If this is not the case, you can join theH Adjust the end stop marked with the screw until the pulley wheels are aligned with the smallest pinion.

2. Set the upper end stop of the rear derailleur

In order to be able to adjust the upper end stop, you first switch to the smallest chainring at the front. Since the shift cable to the rear derailleur is still loose and you cannot shift at the rear, you have to push the rear derailleur with your fingers in the direction of the large pinion. Turning the crank a little can help. As soon as you have the rear derailleur fully "on stop", you check the position of the rear derailleur rollers again. Here, too, the largest sprocket of the cassette must be in line with the derailleur pulleys. If this is not the case, you can turn the withL. adjust the upper end stop with the screw marked.

3. The angle adjustment (B-Tension)

To adjust the angle, the chain remains on the smallest chainring and on the largest sprocket. With theB.-Screw (it is usually marked on newer derailleurs) you adjust the spring in the derailleur suspension and thus the height of the upper pulley. If the spring tension is too loose, the roller can touch the largest pinion. The tension is optimally set when there is a distance of approx. 1 to 1.5 chain links between the teeth of the largest pinion and the pulley.

4. The correct tension of the shift cable

First switch to the large chainring and then turn the adjusting screw for the tension on the gear lever or the rear derailleur almost all the way in. Then put the shift cable back under the Allen screw and tighten it with an Allen key with a slight pull.

5. Adjustment of tension

This step takes practice and patience. If you have done everything correctly so far, the shift setting should almost be correct. Shift to the middle chainring first. Now move the crank and shift through the gears individually. Here you pay attention to the reaction of the chain: If it jumps in the desired direction, everything is okay. If the gear does not immediately jump to the next higher sprocket, the tension must be increased a little. You can do this by unscrewing the adjusting screw by about a quarter turn. You do this until the gear changes immediately. If the chain does not jump to the next smaller sprocket immediately after shifting, the shift cable must be relieved a little. To do this, turn the adjusting screw back in a little. Now the chain should jump onto the selected sprocket immediately after changing gears.

TIP: We recommend a Assembly standby attaching the wheel. This makes the work much easier!

6. Test drive!

Last but not least, I recommend a little test drive. Switch through all gears again and adjust the tension a little if necessary.

B. Adjust the front derailleur

If you are traveling with a double or triple drive, we will now explain how you can also adjust your front derailleur:

1. The correct height of the derailleur

Your derailleur is at the right height when there is about 1 to 3 millimeters of space between the guide plate and the teeth of the large chainring. If this is not the case, you can adjust the height using the clamp or through an elongated hole with a screw. For this you may have to loosen the shift cable. With new front derailleurs, this distance is marked by a small sticker.

2. Adjust the lower end stop of the front derailleur

To adjust the lower end stop, you first have to switch to the largest sprocket and the smallest chainring. Now loosen the shift cable by loosening the Allen screw. Now you can again with theL. Adjust the position of the guide plate with the screw marked. You have correctly set the end stop when the chain is barely touching the guide plate and there is approx. 0.5 to 1 millimeter of clearance.

DANGER: If the lower end stops are set too far, the chain can jump from the chainring onto the bottom bracket shell when shifting.

3. Fix the shift cable

After you have adjusted the lower end stop, you can mount the shift cable on the front derailleur again. To do this, simply fix the shift cable again under slight tension with the Allen screw.

4. Adjust the upper limit stop of the derailleur

Now shift to the largest chainring and the smallest sprocket. In order to set the upper end stop, use the button here H screw in the guide plate marked so that it barely touches the chain.

DANGER: Adjusts the end stops a little tighter. Because here, too, the following applies: If the end stop is set too far, the chain jumps off the blade when switching. In addition, experience has shown that new gearshift cables and outer sleeves still settle a little.

5. Adjust the tension of the front derailleur

Once all the end stops have been set, it is now - as with the rear derailleur - that the tension comes into play. To do this, switch to the middle leaf and the largest pinion. Now the tension changes until the chain no longer rubs against the inside of the guide plate.

6. Test drive!

As before, I recommend you finally to take a little test drive. Switch through all the gears again and adjust the tension if necessary.

TIP: If the chain slips during the test drive, the drive may be worn. A wear gauge provides information on whether the chain or even the cassette / chainrings need to be replaced. The two-wheel mechanic you trust will help in case of doubt!

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