Without Derailleurs, shifting would be difficult, if not impossible. Front derailleurs shifts chain from one chainring to another while pedaling and rear derailleurs move chains between sprockets/cogs and take up any chain slack that occurs when you move to a smaller sprocket.
Because of their important functions, derailleurs should be well cared for. They should be regularly cleaned and oiled and should also be replaced when worn or damaged. Failure to do this can lead to improper/bad shifting.
In this article, we’ll be telling you signs to look out for, to know when your derailleurs need replacement. We’ll also be discussing how to replace them and a whole lot of information about derailleurs you need to know as a cyclist.
Should You Change Your Derailleur?
Not all shifting problems are caused by derailleurs. The problem could be with your shifters, shifter cables, chain, derailleur hangers, etc. So be sure to check those before changing your derailleurs.
The problem could also be fixed by adjusting your derailleurs instead of changing them, so if there’s no sign of wear, adjust the derailleurs first.
That being said, you should change your derailleur when you notice signs of wear or when it’s no longer working properly.
Instead of managing or trying to repair them, you should replace them immediately.
Derailleurs don’t often get worn or damaged, but some of their parts do, and when that happens, changing the whole derailleur is advisable. As this can sometimes be safer and less stressful
Signs to Look Out For
1- Improper Shifting
When you notice your bike isn’t shifting properly, and you have checked all the other components we talked about and are sure they aren’t the problem then you need a new derailleur.
You may find it difficult to shift to larger cogs, experience inconsistent shifting, or discover you can’t shift at all. Worn-out derailleurs can be a headache.
Clean and oil your derailleur when you notice these things but if these problems persist, it’s time to replace that derailleur.
2- Worn Pivots
After many miles of riding, it is not unusual to find the pivot joints on your derailleur is worn out. This will cause excessive side play and sloppy/sluggish shifting.
When this happens, it is time to replace your derailleur, as fixing this problem is close to impossible.
3- Worn or Broken Spring
When your derailleur spring breaks or gets bent, it may be time to replace your derailleur. Replacing springs on derailleurs can be difficult and sometimes the springs are attached to rivets on the derailleur, so it’s impossible to remove the broken/bent ones or fix new ones.
Derailleur springs also get worn over time. You may notice that the spring is no longer strong enough to keep chains tensioned. This will affect shifting and it’s better to replace derailleurs promptly. Your bike chain can also be affected by worn pulleys. When the diameter shrinks it could make the chain run noisy.
4- Worn Jockey Wheels
Most people replace their derailleur’s jockey wheels when it stops working or starts malfunctioning instead of replacing the derailleurs. This is fine as it is cheaper and will work fine with your derailleur.
However, if you have changed jockey wheels or other parts of your bike derailleur many times already, it’s time you replace that derailleur. Chances are, it’s getting worn out already. It may fail when you least expect it and can be a nuisance.
How Much Does It Cost to Replace a Derailleur?
There’s no standard cost for replacing a derailleur. But these few tips should help you know the average cost
Rear derailleurs are not universal. Different bike types, different derailleurs so they don’t cost the same. Models also differ. A rear derailleur could cost between $41 to a couple hundred.
For example, a Shimano Dura-Ace 9070 Di2 rear derailleur costs about $700, and an XT M8000 rear derailleur costs between $83-$124.
Front derailleurs are always cheaper than the rear derailleurs of a particular bike.
If you’ll be replacing it at a bike shop, you could be charged between $15-$50 depending on the shop and your location.
If you’ll be replacing it yourself, then you need to buy tools if you don’t have them already.
How Long Do Derailleur Cables Last?
Generally, derailleur cables last for a long time. It could last between 2 to 5 years or even more. But a lot of things determine this.
Like how often you clean and lubricate them, how often you ride, the conditions you ride in, and so on. This could determine the life span of your derailleur cables.
It’s not unusual for cables to get damaged just after few months of driving. It mostly depends on you, and sometimes the quality of the cables.
How Hard Is It to Change a Derailleur?
Bike derailleurs aren’t difficult to change. Follow these few steps and you can accomplish the task yourself in a few minutes. Let’s change the rear derailleur first.
1- Allen key
STEP 1- The first thing you’ll need to do is shift your gear onto the smallest sprocket and then remove the chain on your bike. This will make it easier for your derailleur to be changed.
If you’re replacing the chain, you can just cut it off. If not, locate the master link and disengage it with a chain quick link pliers. The master link sometimes comes in a different color, so it’s easy to spot on the chain.
STEP 2- The next thing is to remove the shifter cables. Unscrew the end cap on the shifter cables and pull it off. Then use an Allen key to undo the hex bolt, but don’t remove it. Just undo it enough for the shifter cables to be freed from it.
Remove the cables from the derailleur.
STEP 3- Unscrew the mounting bolt, that attaches the rear derailleur to the derailleur cage. This should free your old derailleur.
STEP 4- Now it’s time to install the new derailleur. Attach the new derailleur to the derailleur cage, making sure it’s rightly positioned. The B tension screw should be positioned behind the flat on the hanger and the derailleur should be standing straight. Grease the new mounting bolt before using it to attach the derailleur to the cage.
STEP 5- Thread the cables through the barrel adjuster and around the hex bolt. Screw it tight and fix the end cap.
STEP 6- Now reroute the chain through the jockey wheels on the derailleur and then reconnect it with the pliers. You’ll need a new bolt.
That’s it. You’re done changing your rear derailleur.
For your front derailleur, just
1- Shift the gear unto the smallest chainring.
2- If you don’t want to disengage the chain, locate the derailleur’s cage’s tail screw and undo it slightly. Just until the chain can be released. Let the chain sit somewhere on the bike where it won’t get in the way.
3- Remove the cables and then undo the derailleur from the derailleur cage. From here you can follow the steps we explained for the rear derailleur. After changing the front derailleur, thread the chain through the cage again and tighten the tail screw.
How to Make Your Derailleur Last Longer?
If you keep your derailleurs happy, there’s less chance of it getting worn or needing replacement. This will save you the stress of shopping for compatible ones and changing them. It’s also cheaper. You won’t need to spend extra money getting new derailleurs and having them fixed.
These are some of the ways you can maintain your derailleurs.
1- Don’t make a habit of riding in wet conditions or the mud. It’s easy for derailleurs to get gunked up and start shifting poorly. If you must ride in these conditions, then you should clean your derailleurs after each ride.
Mud splashes and water not cleaned immediately can get the bolts and other parts of your derailleur rusted. It won’t be long before you can’t ride without changing them.
2- Clean and lubricate your derailleurs regularly. Do routine checkups on your bike and clean it regularly. Pay attention to the jockey wheels, cages, and pivots while cleaning. You should also lubricate the pivots and jockey wheels.
Dirt makes derailleur pivots sticky and should be prevented.
Derailleurs generally last for years. Occasionally, some of its components like the jockey wheels, springs, etc. can get worn and need replacement.
When derailleurs get worn eventually though, they need to be replaced immediately. There are signs to look out for if you want to know if your derailleurs are worn and need replacement, and we’ve discussed it in detail.
Replacing derailleurs isn’t difficult and you can do it yourself, provided you have the necessary tools. There are ways of taking care of your derailleurs and your bike in general, to make the derailleurs last long. This is way cheaper than replacing it all the time because of wear or damage.