How To Install A Rear Derailleur On A Mountain Bike (Step By Step)

Welcome to our step by step guide on how to install a rear derailleur on a mountain bike. A rear derailleur is an essential component of your bike’s drivetrain, responsible for smoothly shifting the chain between gears as you ride. If your rear derailleur is damaged or not functioning properly, it can affect your biking performance and make it difficult to enjoy your rides.

Installing a new rear derailleur may seem intimidating at first, but with the right tools and a little bit of patience, it’s a task that can be accomplished by anyone. In this guide, we’ll walk you through the process step by step, so you can get your mountain bike shifting smoothly in no time.

Now, let’s get started!

Installing a new rear derailleur on your bike can seem intimidating at first, but with the right tools and a little bit of patience, it’s a task that can be accomplished by anyone. Follow these steps to get your bike shifting smoothly in no time:

Gather all the necessary tools: a bike stand or a way to secure your bike, a 5mm Allen wrench, a small Phillips head screwdriver, and a pair of pliers.
Shift your bike into the highest gear, so that the derailleur is in the most relaxed position. This will make it easier to work on and adjust.
Remove the old derailleur by loosening the pinch bolt that holds the cable in place and then removing the bolt that holds the derailleur hanger in place.
Attach the new derailleur to the derailleur hanger using the bolt that you removed in step 3. Make sure the derailleur is facing the correct direction and that it is aligned with the largest cog on your cassette.
Insert the derailleur cable into the pinch bolt and tighten it down. You may need to use pliers to get a good grip on the bolt.
Adjust the derailleur limit screws to make sure the derailleur can shift smoothly into all gears. To do this, shift your bike into the highest gear and turn the high limit screw clockwise until the derailleur just touches the largest cog. Then, shift into the lowest gear and turn the low limit screw clockwise until the derailleur just touches the smallest cog.
Test your shifting by shifting through all the gears to make sure everything is working smoothly. If you have any issues, make small adjustments to the limit screws until you get the shifting performance you desire.

With these steps, you should now have a properly installed rear derailleur on your bike. Don’t be afraid to ask for help or seek guidance from a professional if you have any questions or encounter any difficulties along the way.

Things to Consider Before Choosing your Mountain Bike Rear Derailleur

There are many different options available when it comes to choosing a rear derailleur for your mountain bike, and the best one for you will depend on your specific needs and preferences. Here are a few factors to consider when selecting a mountain bike rear derailleur:

Compatibility: Make sure the derailleur is compatible with your bike’s drivetrain and frame. You’ll need to consider the number of gears on your cassette, the type of shifting system you have (such as Shimano or SRAM), and the size and shape of your derailleur hanger.
Material: Look for a derailleur made of durable materials that can withstand the rough terrain and conditions of mountain biking. Aluminum is a common choice, as it is lightweight and strong.
Performance: Consider the type of riding you’ll be doing and choose a derailleur that is designed for those conditions. For example, if you’re planning on tackling steep terrain and big drops, you might want a derailleur with a long cage for more chain wrap and a wider range of gears.
Price: Determine your budget and look for a derailleur that offers good value for the price. Keep in mind that a more expensive derailleur doesn’t necessarily mean it’s the best option for you.

Some popular mountain bike rear derailleurs include the Shimano Deore M6000, the SRAM GX Eagle, and the Shimano XT M8100. Ultimately, the best rear derailleur for your mountain bike will depend on your specific needs and preferences, so take the time to do your research and choose a derailleur that will suit your riding style and budget.

Best Mountain Bike Rear Derailleur

Here is a list of some popular mountain bike rear derailleurs that are highly rated by riders and reviewers:

Shimano Deore M6000: This affordable derailleur is made of durable aluminum and features a long cage for a wider range of gears. It also has a smooth and precise shifting action.
SRAM GX Eagle: This high-performance derailleur is designed for aggressive riding and features a strong and lightweight construction. It offers a wide range of gears and smooth shifting across the entire cassette.
Shimano XT M8100: This derailleur is made of lightweight aluminum and features a long cage for a wide range of gears. It also has a smooth and precise shifting action and is designed to handle the demands of aggressive mountain biking.
Shimano XTR M9100: This top-of-the-line derailleur is made of lightweight and durable materials and offers smooth and precise shifting across the entire cassette. It is designed for high-performance riding and is suitable for a wide range of terrain.
SRAM X01 Eagle: This high-end derailleur is made of lightweight and durable materials and offers smooth and precise shifting across the entire cassette. It is designed for aggressive riding and features a wide range of gears.

Overall, the best mountain bike rear derailleur for you will depend on your specific needs and preferences, so be sure to consider factors such as compatibility, material, performance, and price when making your selection.

How Much Does It Cost To Replace A Rear Derailleur?

The cost of replacing a rear derailleur on a mountain bike can vary depending on a number of factors, including the type of derailleur you choose, where you purchase it, and whether you have it installed by a professional or do it yourself. Here are a few estimates of what you might expect to pay:

Rear derailleur: Prices for rear derailleurs can range from around $30 for a basic model to $200 or more for a high-end option.
Tools: If you don’t already have the necessary tools, you’ll need to factor in the cost of purchasing them. A basic set of tools, including a bike stand, Allen wrenches, and a screwdriver, might cost around $100 or more.
Professional installation: If you prefer to have a professional mechanic install your new derailleur, you can expect to pay anywhere from $50 to $100 or more for labor.

Overall, you can expect to pay anywhere from $80 to $300 or more to replace a rear derailleur on your mountain bike, depending on the factors mentioned above. Keep in mind that this is just a rough estimate and actual costs may vary.

Is It Easy To Replace A Rear Derailleur?

Replacing a rear derailleur on a mountain bike is a task that can be done relatively easily with the right tools and some patience. It involves removing the old derailleur and attaching a new one, as well as adjusting the limit screws to ensure smooth shifting. While it may be a little intimidating at first, most people with basic mechanical skills can learn to do it with some practice. It’s a good idea to gather all the necessary tools beforehand, including a bike stand or a way to secure your bike, a 5mm Allen wrench, a small Phillips head screwdriver, and a pair of pliers. Shift the bike into the highest gear before getting started, and make sure to test your shifting after the new derailleur is installed to ensure everything is working properly.

Will Any Derailleur Fit On My Bike?

Not all derailleurs are compatible with all bikes, so it’s important to choose a derailleur that is designed to work with your specific bike. Here are a few factors to consider when determining whether a derailleur will fit your bike:

Drivetrain compatibility: Make sure the derailleur is designed to work with the type of shifting system you have on your bike. For example, a derailleur designed for a Shimano drivetrain will not work with a SRAM drivetrain.
Number of gears: The derailleur should be compatible with the number of gears on your cassette. For example, a derailleur designed for a 9-speed cassette will not work with a 10- or 11-speed cassette.
Derailleur hanger: The derailleur should fit onto the derailleur hanger on your bike. If the hanger is damaged or incompatible with the derailleur, you may need to replace it as well.
Cable routing: Some bikes have specific cable routing that may not be compatible with all derailleurs. Be sure to check the cable routing on your bike and choose a derailleur that is compatible.

Overall, it’s important to do your research and choose a derailleur that is designed to work with your specific bike. If you’re not sure which derailleur is compatible with your bike, it’s a good idea to consult with a professional mechanic or refer to the manufacturer’s recommendations.

Are Bike Derailleurs Universal?

Bike derailleurs are not universally compatible with all bikes. Different derailleurs are designed to work with specific types of drivetrains, number of gears, and derailleur hangers, so it’s important to choose a derailleur that is compatible with your specific bike. Factors to consider include drivetrain compatibility, number of gears, derailleur hanger compatibility, and cable routing compatibility. It’s important to do your research and choose a derailleur that is designed to work with your specific bike.

When Should I Replace My Derailleur?

There are a few signs that it might be time to replace your bike’s derailleur:

Shifting is slow or inaccurate: If your derailleur is not functioning properly, you may notice that shifting is slow or that the chain does not move smoothly between gears. This can be a sign that the derailleur is worn out or damaged and needs to be replaced.
Derailleur hanger is bent: If the derailleur hanger is bent, it can cause shifting problems and damage to the derailleur. If you notice that the hanger is bent, you’ll need to replace it along with the derailleur.
Chain skips gears: If the chain skips gears when you’re shifting, it could be a sign that the derailleur is worn out or damaged. In this case, you’ll need to replace the derailleur to get your bike shifting smoothly again.
Derailleur is damaged: If the derailleur has been damaged in a crash or has become too worn to function properly, it will need to be replaced.

Overall, if you notice any of these issues with your derailleur, it’s a good idea to replace it to ensure that your bike is shifting smoothly and operating at its best.

Final Thoughts

Installing a new rear derailleur on your mountain bike can be a fairly straightforward task with the right tools and some patience.

Once you have the right tools, start by shifting your bike into the highest gear to put the derailleur in the most relaxed position. This will make it easier to work on and adjust. Next, loosen the pinch bolt and remove the bolt that holds the derailleur hanger in place to remove the old derailleur. Then, attach the new derailleur to the derailleur hanger, making sure it is facing the correct direction and aligned with the largest cog on your cassette. Insert the derailleur cable into the pinch bolt and tighten it down, and then adjust the limit screws to ensure smooth shifting into all gears. Finally, test your shifting by shifting through all the gears to make sure everything is working smoothly. With these steps, you should be able to successfully install a new rear derailleur on your mountain bike.