The rear derailleur is the part of the bike that moves the chain from cog to cog. Over time, this is prone to wear and will exhibit several problems. From the cable to the hanger, different parts that are connected to the rear derailleur are prone issues that will negatively impact the overall performance of your bike.
In this article, we’ll talk about some of the most common rear derailleur problems that you will encounter. Most of these problems warrant simple solutions, so you can fix the bike derailleur without paying a pro for the job.
The Most Common Rear Derailleur Problems You Will Encounter
Keep an eye on the problems mentioned below and be sure to know rear derailleur troubleshooting to address these issues without paying a pro to do the job for you.
1. Friction in the Cable System
Gunk in the cable system can penetrate the housing and limit the functionality of the rear derailleur. This will slow shifting as it limits the movement of the derailleur. The cable can also split and get stuck, causing the friction.
To fix the cable system and prevent it from affecting the rear derailleur, start by shifting to the highest or smallest gear. Loosen the screw that holds the cable on the derailleur. Slide the cable up and down until you do not feel a resistance. This means that friction has been eliminated.
2. Bent Hanger
The hanger is what attaches the rear derailleur to the bike frame. It can be made of either aluminum or steel. Over time, like the other parts of a mountain bike, the hanger shows signs of wear and tear, such as bending. When this happens, the rear derailleur and pulleys will misalign with the rest of the system.
When the hanger is bent, an easy solution is to straighten it if it is made of aluminum. In instances when it can no longer be spared, the best thing to do is to replace the bent hanger to restore the peak performance of the rear derailleur. Thick hangers or those made of fragile materials cannot be bent, so replacement is your best bet.
3. The chain is Skipping or Falling Off
When the rear derailleur is problematic, bike chains can skip or fall off. This can cause a problem in gearing. You will notice that the gears will be unresponsive or there will be a slow response upon shifting.
From the rollers to the rivets, the parts of the chain are prone to wear over time. Unable to withstand abuse, they will also cause problems to the rear derailleur. It can also cause premature wear of the cog. To improve the performance of the chain and prevent it from affecting the rear derailleur and the cog, the right MTB chain lubes can be your savior.
4. Misalignment of the Rear Derailleur
Especially in a mountain bike, the rear derailleur can move a lot. This is the case when you are using the bike on rough terrains and for aggressive riders. When the rear derailleur is out of alignment, the chain will skip cogs or not move when you are shifting.
Shift the gear to the smallest cog and biggest chainring. Loosen the cable that connects to the rear derailleur. Next, find the high and low adjusters. Adjust individually until the chain is moving smoothly then check if it is already aligned with the rear derailleur.
5. Dirt and Moisture
Like the other parts of the bike, dirt and moisture can also limit the functionality and performance of the rear derailleur. Whether it is rain, mud, dust, and other elements, it can cause wear to the derailleur.
When you clean your bike, do not forget the rear derailleur. It is not as big as the frame or the wheels, but it requires your attention. Brush the derailleur and use a bike degreaser or lubricant. Make it clean and smooth so that the chains can move properly.
6. Chain Wear
The chain is another part of the bike that experiences a beating with regular use. It affects its ability to transmit power to the rear wheel. Damages to the chain can also result in stretching, which is what will cause the gears to skip.
If the chain is worn out, consider a replacement to avoid affecting the rear derailleur. If it can still be spared, then you can save money by lubricating the chain. This will help in the restoration of its peak performance while also making the chain and your bike look better.
7. Incompatible Equipment
The drivetrain of your bike is designed to work in harmony with the other components. One of the most common rear derailleur problems is that it is incompatible with the other parts. Depending on the brand and the model, they might have certain cable requirements that you need to meet.
Chains can also be incompatible with the rear derailleur. They are available in several speeds, which will depend on their width. The shape of the side plate can also be different. Make sure that the chain is compatible with your rear derailleur and the other parts of the bike.
8. Worn Rear Derailleur
As we have mentioned earlier, the bike’s components are prone to wear, and that includes the rear derailleur. Theoretically speaking, it can last a lifetime. You might not need to replace it in most instances. However, in case it wears out, then you need a replacement.
Pull the rear laterally on the lower cage to see if it is already worn out. If it is sloppy, this is also one of the most obvious indications that it is deteriorating. Cleaning is the easiest solution. However, you will find that in some instances, cleaning won’t suffice. Hence, the most logical thing to do is to replace the rear derailleur.
A noisy derailleur can be annoying, especially if it is loud. This can be because of dirt or debris stuck in the components. One of the best things to do for rear derailleur troubleshooting is to clean the derailleur and make sure that there is nothing between the components.
Noise from the rear derailleur can also be evident when the chain is sluggish and damaged. The chain goes through the rear derailleur, and hence, the friction can result in noise. A quick fix is to lubricate the chain so that it will be passing through as smoothly as possible.
10. Limit Screw Problems
The limit screws are important because they restrict the travel of the rear derailleur to the cassette and spokes. These screws will signal to the derailleur when it is time to stop. The limit screw settings will affect the functionality of the rear derailleur and your bike’s gearing system.
For rear derailleur troubleshooting, one thing that you can do is to tighten the screws. Turn the screws clockwise to limit the movement of the chain. If you want to loosen the screw, on the other hand, turn it counterclockwise.
Q: How do I know if my rear derailleur is worn out?
To know if your rear derailleur is worn out, pay attention to the performance of your bike, especially when you are shifting. It will cause shifting problems. There will be a delay in the transition of the chain from cog to cog, which can also slow the bike.
Q: How do I fix my rear derailleur?
To fix your rear derailleur, start by setting the limit screws. Do this by disconnecting the gear cable. Next, turn the barrel adjuster clockwise, select the highest gear, and pull the cable. Fine-tune the cable tension, shift up, and adjust the B-tension screw.
Q: How long should a rear derailleur last?
Rear derailleurs will last almost indefinitely, especially if it is from a trusted brand. Even with the regular use of the bike, the rear derailleur will not experience significant wear. If it does, however, then make sure to fix it as soon as possible before the problem worsens.
Q: Why does my rear derailleur slip?
Rear derailleurs slip when they are worn out. The old chain can also be the culprit. If you have a worn cassette, it also contributes to the problem. A bent derailleur hanger, weak spring, and friction in the cables are other things you can blame for the slipping of your rear derailleur.
Q: How often should you change rear derailleur?
You do not have to change your rear derailleur. It will last indefinitely. When it experiences problems, it is often not the culprit. Look at the other parts of the bike. Servicing the rear derailleur is more than enough without the need for a replacement.
Globo Surf Overview
The rear derailleur has a crucial role to play when changing gears in a bike. When it is damaged, the overall performance of your bike can be compromised. So, pay attention to the rear derailleur problems mentioned above to maximize the functioning of your bike. From misalignment to noise, you should know the basics of rear derailleur troubleshooting.