The 10 Best Mountain Bike Derailleurs Review with Buying Guide
If you take mountain biking seriously, then you need to keep an eye on the quality of all the components of your mountain bike. With time, some of them will need to be replaced and it is a good idea to learn to do this on your own. The best mountain bike derailleurs will improve your mountain biking experience as they guarantee that your MTB will stay responsive in all conditions.
A bike derailleur is a device that allows you to change gears by moving the chain. This means that you can go very fast on smooth trails or can go slow on uphill paths. Every mountain bike has a rear derailleur and a front one. If you start to feel that your bike’s transmission is not as smooth as you need it to be, then it is time to have your derailleurs replaced.
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Quick Answer – The Best Mountain Bike Derailleurs
What is the difference between the Front and Rear Derailleurs?
The rear derailleur has two main jobs. The first one is to keep the chain tense and the second one is to switch gears. When you pedal the bike, the power of pedalling pulls the chain tight. The derailleur then keeps the lower part of the chain in the right sprocket. The front derailleur moves the top part of the chain.
For your MTB to function properly, you want to make sure that both the front and rear derailleur are in perfect condition. In this guide, we focus on rear derailleurs that guarantee the swift and flawless shifting of the gears on your MTB.
Detail Review of Best Mountain Bike Derailleurs
If you are not a professional, you might not be able to pick the best bike derailleur. This is why we asked several experts about their opinions and they helped by reviewing some of the best-sellers on the market. By reading this section, you will be able to pick the right addition to your mountain bike. Every best mountain bike rear derailleur review contains valuable information about the description in addition to the pros and cons of each model.
1. SRAM X4 8-Speed Rear Derailleur
An affordable and versatile rear derailleur is always a great bargain. This derailleur from SRAM is compatible with 7 and 8-speed bikes. It is very durable and is excellent value for the money. It is designed to provide the best performance at an affordable price.
The SRAM X4 allows you to shift gears with minimum effort regardless of the nature of the trail. It allows for fast and precise shifting because it keeps your chain tensed. You can save your effort because your gears will shift easily while minimizing pedaling. This is an excellent derailleur to minimize the chain slap on rough terrains. Although you will have to pair it with SRAM shifters, it is worth the investment. This is a durable derailleur that will last for long.
Pros
- Sturdy and affordable rear derailleur.
- Keeps the chain tensed.
- Compatible with 7 and 8-speed MTBs.
- Allows for precise and fast shifting.
- Minimizes the chain slap.
Cons
- Must be used with SRAM shifters.
SRAM X4 8-Speed Rear Derailleur
2. Shimano Deore 9-Speed Mountain Bicycle Rear Derailleur – RD-M591
When you are looking for a good MTB derailleur, you want to make sure that you are buying an affordable yet durable piece of equipment. This excellent derailleur provides quick and precise shifting. It is also very durable and reliable thus offering outstanding performance in all conditions.
This rear derailleur weighs less than 300 grams yet can help you shift gears in all terrains. It is compatible with various 9-speed MTBs and is very easy to install. You can also use it with your 7-speed bike with no problems whatsoever. You don’t have to be an expert because it is very easy to install. The pin bushings are fluorine-coated. This guarantees that your rear derailleur will last for long. This coating protects the derailleur from humidity that can cause rust thus affecting the shifting of the gears. It is easy to adjust for flawless and silent operation.
Pros
- Affordable rear derailleur.
- Fluorine-coated.
- Easy to install and adjust.
- Precise and quiet shifting.
- Compatible with various MTBs regardless of their speed.
- Good value for the money.
Cons
- Might get a little bent but you can easily bend it back for a flawless performance.
Deore 9-Speed Mountain Bicycle Rear Derailleur – RD-M591
3. Shimano Acera RD-M360 SGS MTB Rear Derailleur
If you are a person looking for a decent upgrade of your mountain bike the Shimano Acera RD-M360 SGS rear derailleur is a good fit for you. It is made of sturdy aluminum metal that can withstand tough riding conditions including mountain trails and off-road biking for riders.
It comprises a long cage making it best suited for different bike models, designs, and from different manufacturers. The chain has 7/8 speed options that can be easily shifted even by novice riders during uphill climbs and descents.
The chain wrap capacity of this mountain bike rear derailleur is 43 teeth which makes even the most difficult rides for riders effortless. The derailleur action is of the top-normal type that is adaptable to all mountain bikes.
You can see that the product comes in dimensions of 1.2 x 1.6 x 2.4 inches. It is light in weight as well making it suitable for smaller sized bikes for teens at only 7 ounces. The product also comes with a one-year manufacturer’s warranty making it reliable. It also has a minimum cog of 11 teeth and a maximum of 34 teeth.
Pros
- Light in weight at 7 ounces or roughly 300 grams making it suitable for teens
- The dimensions of the product are at 1.2 x 1.6 x 2.4 inches
- This has a minimum cog or 11 teeth and a maximum of 34 teeth
- The derailleur action is of top-normal design
- Can be fitted with almost all designs and models of mountain bikes
- Body of this mountain bike rear derailleur is made of aluminum
Cons
- Package does not include a hanger and has to be purchased from the manufacturer of the bike
Shimano Acera RD-M360 SGS MTB Rear Derailleur
4. SHIMANO Altus Mountain Bike Rear Derailleur
The RDM310 model Shimano Altus Mountain Bike Rear Derailleur is a traditional top-normal with a 43 teeth chain wrap capacity. It is made of solid metal capable of withstanding different types of terrain including off-road and mountain trails.
The product dimensions are at 6.3 x 6.3 x 4.7 inches with a total weight of only 1.76 ounces. It comes in a 7/8 speed MTB shift style that is suitable for both youth and city sportbikes.
It is compatible with almost all-mountain bike models from different manufacturers and designs. The 32 teeth upsize from almost any size would help in ascents. Minimum effort required from the rider with such a supremely built mountain bike rear derailleur.
You would not have to look for better options as this technologically advanced derailleur provides just the type of fitting that your bike needs during an upgrade. You can mount it directly with the basic tools without requiring expert help or a complex set of tools. This added upgrade is easy to maintain even for beginners who are starting afresh with a mountain bike.
Pros
- 43 teeth chain wrap capacity provides easier climbing for riders
- The 43 teeth upsize is best suited for uphill climbing with minimal effort
- Can be fitted on almost all mountain bikes manufactured irrespective of models and designs
- Comes in dimensions of 6.3 x 6.3 x 4.7 inches
- It can be easily fitted by anyone without technical expertise
- Easy to maintain, mount, and repair and weighs just 1.76 ounces
Cons
- Due to its lightweight, it is a little flimsy and not appropriate for extreme biking
SHIMANO Altus Mountain Bike Rear Derailleur
5. SHIMANO XT RD-M8000 Rear Derailleur
With the Shimano XT RD-M8000 rear derailleur, you can be assured to get both easy and precise gear shifting. When descending or ascending difficult to manage slopes this gear shift can come as a blessing in disguise even for amateur riders.
Different terrains pose different challenges and the integrated chain stabilizer offers an accurate shifting of gears. It has a total of 11-speed drivetrain gears that are easy to operate effortlessly for riders. The new design of this model makes the process of gear shifting 20% simpler than the earlier models.
It has a direct mount and that eliminates the need for a link and in the process, it effectively reduces flex, weight, and wear on the bike. The entire dimensions of the product are 6 x 6 x 4 inches.
It is also light in weight and hence easy to be fitted on even smaller mountain bikes. The product also boasts of lightweight true aluminum components from the start to finish of the product. You can mount this derailleur to your bike without having expert knowledge or intricate tools.
Pros
- Comes with 11-speed drivetrain gears with ease of operation
- Requires 20% less effort while shifting gears compared to the previous models
- Dimensions of the product are at 6 x 6 x 4 inches
- Low in weight at only 14.4 ounces and hence can be fitted in smaller bikes too
- Made of true aluminum components and are very durable even in tough terrains
- Can be easily mounted with the minimum tools and expertise
Cons
- Does not have a barrel adjuster attached to the product
6. SRAM X.4 Rear Derailleur
SGS-long case is what you get with the SRAM X.4 rear derailleur. The product is black and has a drivetrain spacing of Shimano/SRAM 9 with the largest cog of 34teeth. The minimum cog is of 11 teeth and has 7, 8, 9-speed shifts. Makes the ride effortless for the rider during ascend or descending steep hill rides.
Minimum effort required to shift gears making it best suited even for beginners. The derailleur action is a top-normal model with traditional design. The product comes in dimensions of 17.9 x 13.4 x 10.4 inches.
It is light in weight and is suitable for even mountain bikes for teens as the total weight of the product is just 4.2 ounces. People who wish to purchase it can be assured that it does not require expert help to have it fitted on their mountain bikes.
You would not have to go out to the market to purchase new tools as the basic ones would be good enough for fitting this derailleur. The product is easy to maintain after fitting it to your mountain bike.
Pros
- Comes in dimensions of 17.9 x 13.4 x 10.4 inches and is black
- The total weight of the accessory is at 4.2 ounces making it suitable even for small built bikes
- Minimum cog size of 11 teeth and a maximum of 34 teeth
- Light in weight making it suitable for smaller bikes with a total of 4.2 ounces
- Can be fitted to most bike models with minimal effort
- No expertise required for fitting purposes.
Cons
- Cannot be shipped outside the United States
- No fitting instructions included
SRAM X.4 Rear Derailleur
7. SRAM X5 9-Speed Rear Derailleur
This is the best mountain bike 9 speed rear derailleur for flawless and precise shifting on any trail. It is compatible with 9-speed bikes and allows for fast gear shifting, thus giving you the chance to keep your eyes on the trail ahead of you.
Installing and adjusting this rear derailleur is very easy even if you haven’t done any repair work before. It is quite affordable and will allow you to save your time and effort. You don’t have to visit the bike shop for an easy repair because it doesn’t take much to mount. With light shifting, you get to enjoy more of your time on the trail because your bike moves smoothly. It is noticeably faster than other derailleurs on the market. It is an affordable yet excellent upgrade.
Pros
- Budget-friendly derailleur.
- Lightweight yet durable design.
- Easy to mount and adjust.
- Faster shifting.
- Light shifting to save your effort.
Cons
- The cage is thin and can bend easily.
8. SRAM GX Bicycle Rear Derailleur with 1 x 11 Speed Long Cage
This rear derailleur from SRAM provides the performance of high-end models at an affordable price. It is compatible with a number of gears available thus enabling you to shift precisely and swiftly on any trail. It is made to guarantee accurate and quick gear shifting regardless of the nature of your trail.
The offset pulleys combine with the tall square-toothed X-Sync profile to better engage and manage the chain. It eliminates ghost shifting while reducing shifting force. It is one of the best derailleurs that will save your effort no matter how challenging the trail is. It also keeps your MTB stable by maintaining consistent tension on the chain. The design allows for easy and quick installation thanks to the sealed cartridge bearings. It keeps the derailleur locked out of the way as it doesn’t interfere with the wheel for easy installation and removal.
Pros
- Compatible with various gears available on the market.
- Precise and swift shifting.
- Better chain engagement.
- Keeps the tension of the chain.
- Reduces shifting force.
Cons
- You need to be careful while installing it, otherwise, it can get broken.
SRAM GX Bicycle Rear Derailleur with 1 x 11 Speed Long Cage
9. Shimano Tourney 7/8-Speed Mountain Bicycle Rear Derailleur
The minute you see this derailleur, you will realize that there is a lot to like. It is very durable yet, it provides the performance of high-end models that cost a lot more. It comes with a smart cage that allows for better compatibility which makes it very versatile.
Double Servo-Panta Mechanism allows this derailleur to deliver the best shifting on all trails. The guide pulley tracks the cogs closely to minimize problems while shifting even at heavier loads. This is the best derailleur for optimizing your pedaling power since it shifts easily and precisely. It is very easy to install and adjust. Even if you are not an expert, you will be able to enjoy the best shifting experience. It is compatible with various mountain bikes and doesn’t cost much.
Pros
- Affordable lightweight rear derailleur.
- Durable and sturdy design.
- Smart cage for better compatibility.
- Easy to install and adjust.
- Precise and fast shifting.
Cons
- You need to be careful while installing it because it might bend.
10. Shimano Acera RD-410 Mountain Bike Rear Derailleur
This is a budget-friendly rear derailleur that will instantly improve the shifting on your MTB. It is compatible with 8-speed mountain bikes and is the perfect combination of an affordable price and flawless performance.
The derailleur is made of steel and aluminum for the best performance. It is the best rear derailleur with low-friction for smooth and crisp shifting. The design of the rear derailleur allows for excellent shifting under heavy load and maximum acceleration. This is a lightweight derailleur for easy and precise shifting. It even features SGS long cage design for a wide range of gear shifting. The oversized tooth pulleys guarantee that this derailleur won’t malfunction. This is the best budget mountain bike derailleur and is very easy to mount and adjust.
Pros
- Budget-friendly rear derailleur.
- Made of aluminum and steel.
- The best combination a good price and high-quality performance.
- Excellent shifting at maximum acceleration.
- Wide range of gear shifting.
- Easy to mount and adjust.
Cons
- It is a little clunky.
Shimano Acera RD-410 Mountain Bike Rear Derailleur
How to Choose the Best Mountain Bike Derailleurs?
Whether you are an avid mountain biker or only ride occasionally, you need to guarantee that your gears can shift easily. This guarantees that you can ride safely because you will be able to go up or down any trail with minimum effort.
There are some features that you need to pay attention to when you are shopping for the best mountain bike derailleur. You have to take them into consideration before making a purchase:
i. Compatibility
This is the first factor that you should think about while shopping for a derailleur. As a rule of thumb, you shouldn’t mix and match parts of different components or generations. You should also make sure that your derailleur is suitable for mountain bikes and not road bikes.
Most derailleurs that work for 8-speed bikes can also work for 9-speed bikes, especially if they are SRAM. These derailleurs will work for 7, 8 and 9-speed bikes easily. 10-speed derailleurs will also work with road shifters. Shimano derailleurs are not that compatible and you will have to make the extra investment to buy the appropriate shifters if they are not already installed to your MTB.
ii. Weight
Most high-quality derailleurs weigh less than cheaper models. You need a good derailleur that doesn’t weigh much to allow for the best performance on the trail. Lighter derailleurs are made of aluminum or carbon. They are very durable but might be too expensive. You can always pick a model that combines steel and aluminum.
A heavy derailleur might not the best option since it can affect the speed of your bike. These are usually made of steel which is very durable but is not particularly lightweight. If the weight doesn’t bother you much, you can get away with spending less money your derailleur.
iii. Longevity
More expensive derailleurs are usually made of more durable components. These are designed to last for long because they are very well made. If you tend to ride your mountain bike on a regular basis, or usually go biking on rough trails then you have to buy a heavy-duty model. Cheaper models that are made of thin metal or can bend easily are not suitable. You can always save some cash if you take mountain biking lightly.
iv. Easy to Install and Adjust
How much time are you willing to spend on installing and adjusting your derailleur? It is always a good idea to buy a model that you can easily install and adjust on your own. You need to make sure that your derailleur comes with all the parts that you will need for the installment process.
v. Finish
While the finish doesn’t have much to do with the performance of the derailleur, it is still an important feature to consider. Most high-quality models look elegant, unique and will attract attention. You can spend more money to install a shiny derailleur if you want your mountain bike to stand out. The finish also protects your derailleur from the elements and ensures that it will last for long.
Conclusion
If it is time to upgrade your MTB, then you need to know everything about the Best Mountain Bike Derailleurs. Don’t worry if you are not that experienced with installing different bike parts. Most of the good derailleurs come with easy instalment instructions that will allow you get your MTB back on the trail.
A good derailleur will allow you to shift gears flawlessly with no problems whatsoever. Make sure that you pick a good product that will work for your mountain bike and will keep your chain tensed on all terrains. These derailleurs come in all shapes and sizes and you can always find a good one regardless of your budget
