How to Install a Mountain Bike Rear Derailleur in 5 Simple Steps

Mountain biking is a thrilling outdoor activity that is enjoyed by many. However, as with any equipment, it can be prone to wear and tear. One of the most common issues with mountain bikes is the derailleur, which can become damaged or worn over time. Replacing a damaged rear derailleur may seem like a daunting task, but it is actually a simple process that can be done in just a few easy steps.

In this article, we will show you how to install a mountain bike rear derailleur in 5 simple steps. You’ll learn how to identify when your derailleur needs replacing, what tools you’ll need, and how to properly install your new derailleur. Whether you’re a seasoned mountain biker or a beginner, this guide will help you get back on the trails in no time.

Key Takeaway
To install a mountain bike rear derailleur, first, remove the old derailleur by loosening the retaining bolt and pulling it off. Then, attach the new derailleur to the hanger using the mounting bolt. Adjust the position of the derailleur so that the jockey wheel lines up with the cassette. Finally, adjust the limit screws and cable tension to ensure smooth shifting.

Gather Necessary Tools and Supplies

Gather Necessary Tools and Supplies

Before starting the installation process, it’s essential to gather all the required tools and supplies. Here’s a list of what you’ll need:

1. Rear derailleur: Get the correct model that fits your bike frame and matches the number of speeds on your cassette.
2. Derailleur hanger alignment gauge: To check and straighten the derailleur hanger alignment.
3. Allen wrenches: To remove the old derailleur and install the new one.
4. Cable cutters: To trim and cut the shifter cable housing and inner cable.
5. Pliers: To crimp the cable end caps and adjust the derailleur cage.

Besides this, you will also need a workstand or a way to securely prop up your bike, a set of gloves to protect your hands, and a clean work area with proper lighting. Without these necessary tools and supplies, your derailleur installation will be difficult to impossible, and you run the risk of damaging your bike or the new derailleur.

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Remove the Old Derailleur

Removing the old derailleur is the first step towards installing a new one. This process involves disconnecting the derailleur chain and detaching the old derailleur from the hanger. Before you begin, ensure that you have the necessary tools, including a 5mm Allen wrench and a pair of needle-nose pliers.

Start by shifting the bike’s gears to the smallest sprocket on the rear and the smallest chainring on the front. Release the derailleur cable from the derailleur by unwinding the pinch bolt on the derailleur body. Then, with the needle-nose pliers, disconnect the chain from the derailleur jockey wheels. Finally, use the Allen wrench to remove the derailleur mounting bolt and detach the old derailleur from the bike frame. With these steps complete, you can easily proceed to the next stage of the installation process, which is fitting the new derailleur.

Prepare and Install the New Derailleur

Once you have removed the old rear derailleur, you need to prepare and install the new derailleur. Before doing so, check if the new derailleur is compatible with your bike’s chain and cassette. Match the number of speeds on your bike with the number of speeds on your new derailleur.

To install the new derailleur, start by attaching the derailleur hanger to the frame, followed by connecting the derailleur cable. Secure the cable in place with the pinch bolt, and adjust the cable tension as per the manufacturer’s guidelines. Finally, adjust the B-limit screw to ensure that the jockey wheel is properly aligned with the cassette and the chain runs smoothly. With these steps, your new rear derailleur is ready to roll!

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Adjust the Derailleur Limits and Cable Tension

Once the rear derailleur has been installed, the next step is to adjust the limits and cable tension. The derailleur limits control the range of motion of the derailleur and prevent the chain from falling off the cassette. The high limit screw controls how far the derailleur can move towards the smallest cog, while the low limit screw controls how far towards the largest cog it can move. To adjust the limits, shift the chain onto the largest cog and turn the low limit screw until the jockey wheel lines up with the cog. Then, shift onto the smallest cog, and adjust the high limit screw until the jockey wheel aligns with the cog.

The second part of the adjustment process requires fine-tuning the cable tension. Cable tension dictates the derailleur’s position and movement as you shift gears. To adjust the cable, shift to the smallest cog and loosen the cable by turning the barrel adjuster until the jockey wheel lines up. Next, shift to the largest cog and pull the cable snug, but not tight. As you shift through the gears, make minor adjustments to the cable tension until the shifting feels smooth and precise. With the derailleur limits and cable tension set, you’re ready to hit the trails with a properly functioning drivetrain.

Test the Shifting Performance

Now that you’ve installed the new rear derailleur on your mountain bike, it’s important to test its shifting performance. It ensures that the derailleur is installed properly and functioning correctly. There are a few simple steps you can follow to test the shifting performance of your newly installed rear derailleur.

First, shift through all gears on your bike to make sure that the derailleur is shifting smoothly and accurately. Then, take the bike for a spin and test the shifting under load. Shift up and down through the gears while climbing hills or accelerating on flat terrain to ensure the derailleur is working correctly under real-world conditions. If you notice any issues, such as slow or missed shifts, adjust the derailleur until it shifts smoothly and accurately. After testing and adjusting, your mountain bike’s rear derailleur should be functioning perfectly and ready for your next adventure.

Troubleshoot Common Installation Issues

Despite being a seemingly straightforward process, there are a few common issues that can arise during the installation of a mountain bike rear derailleur. One of the most common issues is a misaligned derailleur hanger, which can cause poor shifting or even damage to the derailleur itself. To avoid this issue, it is important to ensure that the hanger is straight before beginning the installation process.

Another common issue is improper cable tension, which can lead to difficulty shifting or even shifting failure. It is important to follow the manufacturer’s instructions carefully in order to ensure proper cable tension, and to make any necessary adjustments before taking the bike out on a ride. By troubleshooting these and other common installation issues, riders can enjoy seamless shifting and improved performance from their mountain bike.

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Maintain and Fine-tune Your Derailleur

After successfully installing your mountain bike rear derailleur, you need to maintain and fine-tune it regularly for optimal performance. Here are some simple steps to follow:

Firstly, check the alignment of the derailleur with the cassette. Ensure that the jockey wheel aligns with the cog and that the derailleur cage doesn’t touch the spokes. Secondly, adjust the limit screws correctly to prevent the chain from shifting out of the gear range. Thirdly, check the cable tension and adjust if necessary to ensure smooth shifting. Finally, lubricate the moving parts of the derailleur for optimum performance.

Fine-tuning your derailleur is crucial for smooth and efficient gear changes. You may need to adjust your derailleur after a few rides to account for cable stretch and other factors. By maintaining and fine-tuning your derailleur, you’ll ensure maximum efficiency and longevity of your mountain bike’s shifting system. Don’t hesitate to seek help from a professional mechanic if you’re unsure about any step.

The Conclusion

Installing a rear derailleur on a mountain bike isn’t as tough as it may initially seem. Though the exact steps may vary according to the manufacturer’s instructions, following a few simple tips can make the process easy and fast. Firstly, ensure the new derailleur you’re installing is compatible with your bike’s speed, brand, and model. Then, you need to adjust the derailleur’s stopping points and ensure the chain length is accurate.

Before starting the installation procedure, make sure you have all the necessary tools and equipment. You don’t want to start only to find out you don’t have a crucial tool halfway through. With the guidelines and guidelines shared above, you’ll be able to successfully execute the procedure without hassles and get back to your bike in no time. So what are you waiting for? Grab your tools and let’s start installing your mountain bike’s rear derailleur today!

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