How to make a rear derailleur on a bicycle

How to adjust the rear derailleur

I already had an article on why some bicycles have poor gear shifting. It’s time to discuss directly the setting of the switches itself, and we will start from the back.

I’ll tell you right off the bat that the hardest to tune is a worn out derailleur at the budget level like the Shimano Tourney or Altus. This is due to the fact that there are already so many backlashes in the joints of the mechanism that the setting takes the form of shamanism.

In the past, I, like many other cyclists, believed that tuning was limited to setting the high and low gear set points. The method described in the article I spied on from one mechanic, who was distinguished by his ability to set up the most capricious switches.

It may seem a little complicated, but according to my experience, it allows the most accurate setting of switches, not only high-level, but also budget ones. Therefore, I recommend repeating all the steps described.

vintage bike build. part 9. rear derailleur install

Sometimes I met the opinion that it’s better not to go into programs, if you don’t know how, otherwise you’ll blow everything. Friends, the index gearshift system is very simple and reliable, nothing can be broken there. I practically guarantee that you can set up any switch without any problems with my instructions. Even if something goes wrong, you can go back to the beginning and start again.

Rear derailleur setting

So let’s get started, first I recommend removing the chain. This is not necessary, but without the chain it is much more convenient to define the High and Low breakpoints. Next, release the transmission cable by unscrewing screw A in the picture below. Now turn the rotator B fully clockwise.

Shift the reverse gear shifter (right handlebar shifter) to the highest gear (usually the index finger stick). Now grab a Phillips screwdriver and locate the H adjustment screw on the back of the switch.

By turning this screw, you need to align the idler roller in the same plane with the smallest sprocket in the cassette. There is a little trick here: if the switch is not new and it already has backlash, then sometimes it is necessary to set the roller not ideally along the mowing line, but to shift it literally a hair to the right (when viewed from above from behind).

make, rear, derailleur, bicycle

The next step: we press the switch housing so that, after overcoming the spring tension, push it as far as possible towards the bushing. Holding the switch in this position, use a Phillips screwdriver and screw L to align the plane of the roller with the largest sprocket of the cassette.

Again, if you already had problems with the shift setting, then move the roller a little towards the spokes. But I emphasize. it really should be a little bit. Sometimes, a perfectly aligned derailleur lacks just this small amount to throw the chain onto the farthest star.

Now that we have set the High and Low control points, we return the chain to its place. Then, with our hands, without pliers, we take out the slack in the cable and tighten the screw A. Note that the cable should fit into the groove of the washer of this screw.

After the screw is tightened without fanaticism, turn on the second gear with the shifter on the steering wheel and, while rotating the pedals, start unscrewing the rotator B counterclockwise.In this situation, a repair stand or at least a stand for the rear wheel is very good. If this is not the case, then you can put the bike frame on an ironing board. Well, or, as a last resort, use the help of a friend.

Rotate the pedals and crank until the chain jumps to the second sprocket. All that is left is to bring the switching to perfection. To do this, simply flip from the first to the second star and vice versa, and continuing to play the twist a few clicks back and forth, achieve a clear switch

The index gearshift system is designed in such a way that by setting one speed, you automatically adjust the entire range of gears. If there is no backlash in the derailleur, the cock is even, the frame dropouts are symmetrical, then the work is over. check how the chain runs in the entire speed range. Should be fast, clear and without delays.

If, nevertheless, problems remain (and this, as a rule, is switching on the outermost stars), then you can slightly shift the roller in the direction outward from the outermost stars, using the adjusting screws H and L, as I wrote above. Most importantly, do not get carried away with this with low gears, because the chain can be thrown over the star, and then the derailleur foot will fall into the spokes.

A similar method is shown in this video (sorry, in English, but with a British accent :))

If fresh cables and shirts are installed on the bike, then after a hundred kilometers they can sit in their seats and slightly knock the setting. To do this, again, changing from the first gear to the second and back, select the desired position of the knob B, changing the position by a couple of clicks back and forth.

I hope my note will help you understand how to set up the rear derailleur and close the topic of the fuzzy operation of this mechanism. The fact that the bike is inexpensive does not justify working in the style of two speeds forward, one backward at all.

If the switch is already worn out to such an extent that even fine tuning it is impossible to achieve acceptable work, then do not shaman, but order yourself one. it will work like a clock.

Do not be afraid, try it, this is absolutely not the kind of job to go to bike mechanics.

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For almost 10 years of operation of three multi-speed bicycles of different classes of equipment, I somehow do not even remember that at least once there was a need to touch Low / High. They are always in the unscrewed state, if you twist it, it gets worse. I only turn the adjusting wheel.

Going to a mechanic to adjust the switches is definitely not worth it, in my experience most mechanics do this work very superficially.

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If a switch doesn’t work well, that’s not a reason to buy another one right away. Very often, the problem is solved by cleaning the cassette / derailleur from dirt, replacing the cable / shirt. If you are not sure, it is better to visit a mechanic.

Sometimes a tremendous effect is obtained by cleaning the cable / jacket from dirt, followed by treatment with a chain lubrication spray.

When I changed the switch, I simply drove the wheels upside down and set it up. Everything is written in the case, it is especially important to adjust L and H without a chain, otherwise the foot will not walk exactly, he stepped on this rake. And I liked the remark about the slight displacement of the switch foot from the star, I myself do it from the 1st setting. It seemed to me that it was easier for the switch to work this way, but it turned out it did not seem! Victor, thanks for another good article!

And if the screw H is already unscrewed, that is, it is still necessary to move a little to the right, but it no longer allows you to do this? Shimano Deore stands on the ninth star and throws off the chain after 100 meters. If you adjust the twist on the shifter or the shifter for a couple of clicks, it stops throwing. So I go, I practically don’t use the 9th

Vadim, the ninth. you mean the first, the smallest? Maybe the cock is crooked?

But I had a case, no settings helped, it turned out that a step was knocked down in the cassette. Before me, some Kulibin tried to collect his own non-factory combination of stars and mixed up the gaskets in places. But this is a unique case.

And tell me, is it really possible to improve something in the operation of the switch by rotating the rear screw, which rests against the cock. Not all of them have it, but more or less decent ones already have it. In general, they say that it is needed to adjust the distance from the roller to the stars, but is it really that important??

to Mikhail: and it is better to adjust the limit screws. The hour is uneven, the switch will fly into the spokes, even if this has not happened for 10 years

Alexander8760, if you do not change to a cassette with a different number of teeth on a larger sprocket, then it does not really affect. One has only to check at what distance the video is from the star. Manufacturers recommend 5-7 mm.

Oh, as now I remember the nightmare of the Stels Navigator 810 for 10 thousand rubles and the nightmare with the Shimano tourney setting. Two years ago, I finally gave the bike to my brother, changing the entire body kit for Acera and Alivio, it rides without problems. And I bought myself this year Kross Evado 5.0

Article in the topic. Just fucked merida’s rear derailleur last night. On the middle sprockets, the chain did not bounce to the end of the teeth and snapped disgustingly. The most tangible result was given by tightening the cable by twisting the lamb against the h / s. From the article I did not understand why, when adjusting the position at the largest star, you need to move and hold the switch body with your hand, and not switch it to the desired position with a shifter?

Ilya, because the chain is removed (I wrote at the beginning that the chain must be removed).

Victor, it seems like the mechanism pulls the chain to the side, and not vice versa I probably don’t understand something, but I thought that the goal was to put a star and foot elements in the line

Ilya, the chain introduces its own distortions. The mechanic drew attention to this to me, and then, from my own experience, I was convinced that removing the chain when setting up is a useful exercise, especially if we are not talking about new high-level switches, but a loose budget.

I tried a good video on setting up both on the budget version (led by my wife) and works on my sram x0

It was on the basis of that video that I set up yesterday. It seems to have worked out. Also the wife’s merida) Finally, the peasants got their hands on their faithful)))

I ask for advice. On the spot, everything switches perfectly, but not always when driving. It happens two forward one backward, or two presses are required

Yuri, perhaps the setting is not made accurately, it works without load, but in reality it jams. I would advise you to do everything from start to finish according to my instructions.

There may be mechanical problems: the cassette and chain are so worn out that they switch poorly under load. I had this on a killed set that traveled more than 10,000 km.

Then try to set up, it should help.

I express my deepest gratitude for the article. Finally (not without ordeals, of course) I managed to rebuild the work of the famous Shimano Tourney. It works like a clock, not like a Swiss one, of course, like not very expensive Chinese ones, but it throws the chain exactly in the number of clicks that I do, albeit with a tiny delay. Pereklyuk is practically new. 600 km in total (they don’t let me ride for more than an hour, and even then it’s not apparent), but it turns out to go around the city with traffic lights 18-25 km in this hour. I’ve been riding since July on an Auchan bike the switch turned on in the first week, I tried to rebuild it myself, which even happened once, but then it crawled again. Now with the rear derailleur the question has been resolved, the front has remained. I displaced him in an attempt to find an advantageous position I did not find it. Attention, question: where is the article about the front crossover?

There is no article about the front one yet. But it will be. However, with the front there are no special tricks, any manual on YouTube is suitable, google.

The front derailleur does not work well on my new bike. I look forward to an article about setting up.

and we also don’t forget the robots for the influence of the shifter, which, being finished, may not switch as it should

The shifter is generally the head of everything. And here the switching quality depends very much on its class. the same XTR switches just like a clock, while Deore is far from so clear, not to mention budget. But we are talking specifically about subjective nuances. even the Tourney shifter will work well if the switch itself is precisely tuned.

I will not say anything about the wear of the shifters. I have never met. They usually either switch or do not switch. So that the shifters introduce distortion. do not collide.

Greetings from the future) Loose grips can have a big impact on shifting.

The Terneevskie shifters are generally elementary and there, in principle (as it seems to me), there is nothing to break, except that over time, a little play will appear from the tension of the cable. Outwardly, it looks quite decent and does not inspire fear. And the front derailleur itself works fine, because it is simple to the point of being extraordinary. In it, I am simply annoyed by the friction of the chain on the frame when it is on the extreme stars of the system. Today there was a feeling (while I was adjusting the rear cross-link) that the carriage on the side of the stars is strongly recessed. And my ashanbike. Stern Energy 2.0. a guide for a beginner bike mechanic. Ideal for learning how to fix cycling. It was bought without googling, according to the option: to get much closer in a short time. Reaping the benefits. And an article in the author’s leaked, where everything is essentially and accurate, about the front derailleur, I will be extremely happy, since it will not be possible to load a lot of video via the mobile Internet, and it is more pleasant to read than to watch. In general and short, without the poly-letter: thanks for the current article, I look forward to the next one.

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Victor, or I don’t understand something, or it is necessary to change points 1 and 2 in places: first you suggest to disconnect the cable from the switch, and in the second point you say to click the switch to a small star (without the cable, how?) And did not understand at all 4.th point: we press on the switch housing so that, after overcoming the spring tension, push it as far as possible towards the bushing. Holding the switch in this position, use a Phillips screwdriver and screw L to align the plane of the roller with the largest sprocket in the cassette are we already on a big or still on a small star (like in the previous ones we were all the time on a small one, when did you manage to switch?)? Which way do we push (forward or to the left, when looking at the bike from behind)?

Roman, I didn’t have time. Ivan has already explained everything. Note that in the second paragraph I am writing about not clicking the switch, but the shifter.

Roman., All items are located correctly. What’s the matter? The fact is that we need to remove all external stops, for this we remove the chain and loosen the cable (point 1), while twisting the cable tension regulator on the switch. The shifter to the value corresponding to the smaller star (point 2) can be flipped at any time (between disconnecting the cable and connecting it). in this position, the cable tension is minimal. Then center the top sprocket of the foot with the smaller sprocket and turn the appropriate adjuster (H). after that, manually move the paw to the larger star (point 4), also align it in the center and adjust the offset with the second adjuster (L) so that the chain does not fall out over the edges. After that, we release the paw and it returns to its original position (to the small star), where before it you need to manually pull the cable without any devices, fix it, put on the chain well, further actions can be performed without explanation. I hope I wrote it clearly. I set it up with a chain, tk. no squeeze. inconvenient, but possible.

By the way, be careful with the paw, it can bend, it is better to push the switch. By the way, a question to connoisseurs (arose spontaneously, did not think about it before, did not look for it): for a switch with a reverse spring, the initial position of the paw is under a small star or still under a large?

Hello Victor. And what to do if there is no rotary B?

Oleg, there should be a spinner. If it is not on the switch, then it may be on the shifter. In any case, there must be something that is responsible for the degree of tension in the cable.

Ivan, thank you. There is a twist on the switch.

I’m lazy. I do not remove the chain. It doesn’t bother me at all. On the contrary, it helps. Shows and tells you where to turn.

What and how to do, in my humble understanding. To begin with, make sure that nothing sticks anywhere and crawls easily. otherwise you can fuck for a long time and mediocre. How to check (and provide with simple means) is a separate topic. Then make sure that there are no large backlashes of the switch itself and the upper roller (!). Otherwise it can take a long time.

Further it is possible in different variations, I do not have a rigid method. The sequence of actions is really a fig. You need to understand the principle of what is happening there. WHERE WHERE GOES. Then no problem.

The notorious L and H settings. These are just blunt paw travel stops. Their task is to prevent the chain from jumping out from the cassette. And that’s all. They have no effect on the clarity of the switching. except that it is crookedly tuned, clamped. then they will interfere with the extreme stars.

They can be configured first, they can be configured later, or they may not be configured at all. If you have a more or less high-quality shifter, it will not start up by itself. Better to set up, of course it’s simple.

By tradition. first I tell ABOUT BOLTICS

Starting position: chain on the smallest star. We release the cable completely (we loosen the screw / nut, than it is clamped there). We look at the roller of the switch. it pulls the chain outward, to the right. If this is not the case, unscrew the bolt (I forgot which letter, and I never knew, because pokh. Which does not let out. Look with your eyes, touch your hands. Do not twist the pedals!) Stir? Going outside? Excellent. Unscrew too much (you will see the chain trying to outward). Tighten the screw back to stop. So as not to climb out. See how turning the screwdriver pushes the chain inward towards the frame? Don’t overdo it. Don’t push too inside. It’s all.

A similar operation for setting up the second limiter. I’m lazy, and squeeze the switch all the way to my break. We squeeze the cable in the switch, lightly, without fanaticism, here Kotovsky is right. (True, I did not say why. I explain. so as not to grind, it is difficult to imagine later. But you have to.) Switch to the first star (the first. ALWAYS counts from the frame). The biggest one. We unscrew the second bolt-limiter. To push the crossbar even more towards the frame, you can press on the crossbar (lazy, inconvenient), or you can pull the cable like a bowstring. It’s easier. We look how it climbs FOR the first star, and screw it with a bolt so that it does not climb. The presence of the chain very clearly shows where what. See the inclinations. And how he does not let the bolt. (and why are you removing the chain? an excellent visual indicator of the position of the derailleur)

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Then (or before) (or actually) (the only important thing) you need to adjust the cable so that it pulls, HOW MUCH IS NECESSARY.

We already clamped the cable (fixed) when the switch was on the last star (the smallest). The main thing starts from here.

We rotate the pedals, click the shifter. We click so that the switch moves TO THE SIDE OF THE FRAME. We look closely at the chain. Higher higher wow! Doesn’t want higher?

This means that the cable is NOT TIGHTENED ENOUGH and needs to be tightened a little. This is done in TWO STEPS. Roughly: let go of the bolt, tightened the cable, clamped the bolt. Exactly: we twist the twist at the end of the cable. It is either on the switch itself or on the shifter. We will set up this twist at the final stage as well. It is important to understand: first, twist the twist completely, then tighten the cable with your hand, then tighten it with a nut. Then you will have a RESERVE for fine adjustment.

Then we click the shifter in the opposite direction. It’s easier here. If only I really pulled it over to the previous one, then it will be bad to jump off the chain. Then you need to relax the rope a little. But usually no problem (arms straight?)

The main and final stage. We sit down and go. We click the switch, go through the entire range from the smallest to the largest, and back. Here and there. Here and there. than once. We watch how it switches. The principle is enchantingly simple.

If it doesn’t climb a big star, pull up the cable! If it jumps poorly onto a small star. loosen the cable! Do it (try) a little bit! Half a bite! Leisurely. Half knobs are a quarter turn of the adjusting screw. Usually it is fixed like this, you will understand on your fingers.

Tighten the cable. this is to REMOVE the bolt. The screw, when unscrewed, moves the jacket (cable sheath) away from the clamping point. It is like pulling the clamping point away from the shirt. This is like pulling a cable. clear?

To release the cable is to TURN the adjusting bolt inward. It doesn’t matter where it is installed, on the shifter or on the derailleur.

Do three, or how to reach the golden mean.

Quite simple. From the found satisfactory position (everything works), we begin little by little, twist half a lump in one direction. Until then, until it starts to junk a little. We count half-balls. We write it down. We return to its original state (strictly by the same amount). Then we turn in the other direction. Until it starts to junk a little. We count half-balls.

And then Mmm. Then we calculate the arithmetic mean and click from the extreme position there. And there we are waiting for the very, very middle, the most correct setting. sf

Over time, the setting may slip a little. this happens when the cable is changed. Well, you figured out where to turn, right? It’s a couple hundred kilometers or something. If the setting starts to slip in other circumstances, do not rush to set up, look for the reason!

If it dumps poorly on a smaller star, look for a jam in the cable traction. If it picks up badly on a large one, look for backlash, first of all in the upper roller. If both are bad you already understood, yes?

Super! Thank you very much for such a detailed commentary) Everything worked out!

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.

The adjustment is made with an adjusting drum located on the shifter, on the speed switch itself (for mountain bikes) or on the top 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.

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.

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.

bicycle rear derailleur (handmade,with rack and pinion )

Most rear derailleurs have a screw (Shimano terminology “B-tension adjuster”) to adjust the spring tension of the “B” lever. As a result of 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 adjust, 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 clarity of gear shifting increases. Be careful, the roller should not touch the star, leave a gap of 5 mm.

How To Replace/Upgrade Rear Derailleur On A Bike

Campagnolo rear derailleurs

Since 2001, all Campagnolo derailleur models have A-tension adjustment. 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.