Best Bike Derailleurs of 2025

Jason Kiser Avatar
Jason Kiser
Last Updated: Jan 16, 2025

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Bike derailleurs are an essential component of any modern bicycle. They are responsible for shifting the chain between gears, allowing the rider to adjust their pedaling effort to match the terrain. Derailleurs come in a variety of styles, with different numbers of gears and mounting options to fit different bikes. Some derailleurs are designed for specific types of riding, such as mountain biking or road racing, while others are more versatile and can be used in a variety of settings. Overall, a good quality derailleur can make a big difference in the performance and enjoyment of a bike.

At a Glance: Our Top Picks

Shimano RDM310DL Altus GS Rear Derailleur Cover #TOP 1
Shimano RDM310DL Altus GS Rear Derailleur
ftb score rating icon 9.8
SHIMANO Tourney TY500 6/7-Speed Rear Derailleur Cover #TOP 2
SHIMANO Tourney TY500 6/7-Speed Rear Derailleur
ftb score rating icon 9.7
microSHIFT Mezzo M36 Rear Derailleur Cover #TOP 3
microSHIFT Mezzo M36 Rear Derailleur
ftb score rating icon 9.5

Top 10 Bike Derailleurs

#TOP 1

Shimano RDM310DL Altus GS Rear Derailleur

RDM310DL
Black
DIRECT MOUNT
Shimano RDM310DL Altus GS Rear Derailleur Cover
Shimano RDM310DL Altus GS 7/8-speed Rear Der Black,Long Cage

The Shimano RDM310DL Altus GS Rear Derailleur is a high-quality component that is perfect for city sport and youth bikes. With a chain wrap capacity of 43 teeth and a derailleur action of top-normal, this derailleur is designed to provide smooth and reliable shifting. It has a black color and is compatible with Shimano/SRAM 8 drivetrain spacing. The largest cog is 34 teeth and it weighs 326g.

What We Like
Smooth and quiet shifting
Easy installation
Great value for price
Compatible with various setups
Durable and strong construction
What We Don't Like
No paper instructions included
Minor grease annoyance
#TOP 2

SHIMANO Tourney TY500 6/7-Speed Rear Derailleur

TY500
Black
One Size
SHIMANO Tourney TY500 6/7-Speed Rear Derailleur Cover
Shimano Tourney TY500 6/7-Speed Rear Derailleur

The SHIMANO Rear Derailleur is a bike shifter designed to be compatible with all Shimano 6 and 7 speed shifters. Its advanced light action design makes shifting gears easier and smoother. The SGS cage can handle a wide range of gearing, making it suitable for various terrains. The SIS Rear index shifting ensures accurate and precise gear changes. The 13 tooth pulleys offer long service life and less noise, providing a more comfortable and enjoyable riding experience.

What We Like
High-quality build
Easy installation
Excellent shifting performance
Affordable price
Smooth operation with new chain
What We Don't Like
Lack of setup instructions
Plastic cogs
#TOP 3

microSHIFT Mezzo M36 Rear Derailleur

MSH-RD-M36L
Black
microSHIFT Mezzo M36 Rear Derailleur Cover
MICROSHIFT MEZZO M35 R DERAIL 8/9-SPEED LONG CAGE BLACK

The microSHIFT M36 Rear Derailleur is a lightweight and durable option for your bike. With its weight saving aluminum bracket body and outer link, this rear derailleur helps to reduce the overall weight of your bike, making it easier to handle and more efficient to ride. The steel pulley cage adds strength and durability, ensuring that the derailleur can withstand the rigors of off-road trails and rough terrain. Compatible with Shimano 8 and 9-speed mountain and road systems, this derailleur offers versatility and convenience. Upgrade your bike with the microSHIFT M36 Rear Derailleur and enjoy smoother shifting and improved performance on your rides.

What We Like
Excellent shifting performance
Easy installation
Great value for price
Compatible with various setups
What We Don't Like
Lacks spring assembly
Durability concerns for outdoor use
#TOP 4

Shimano Rear Derailleur, RD-TX800

ERDTX800SGSL
Black
7/8 Speed
Shimano Rear Derailleur, RD-TX800 Cover
Shimano Rear Derailleur, RD-TX800, 7/8 SPD, Direct Attach, Bla

The Shimano Rear Derailleur, RD-TX800, is a durable and efficient 3x8-speed rear derailleur designed for stress-free riding. With its light action shifting performance and double Servo-panta mechanism, this derailleur offers quick assembly and an Allen key type inner cable fixing bolt. It can accommodate a total capacity of 43T, making it a great choice for front bike derailleurs.

What We Like
Lightweight aluminum construction
Smooth and precise shifting
Affordable price point
Easy installation
Durable and reliable performance
What We Don't Like
Inexpensive appearance
#TOP 5

Shimano Acera RD-M3020-SGS Rear Derailleur

ERDM30208SGSL
Black
SGS Long Cage
Shimano Acera RD-M3020-SGS Rear Derailleur Cover
Shimano Acera RD-M3020-SGS Rear Derailleur - 7/8 Speed, Long Cage, Black

The Shimano Acera Rear Derailleur is a high-performance component designed for 7 and 8-speed drivetrains. Its double servo mechanism allows for precise and smooth shifting, ensuring that the rear derailleur moves along the optimal path. This feature enhances the overall performance of the derailleur, making it a reliable choice for cyclists of all levels. The Shimano Acera Rear Derailleur also boasts versatile compatibility, allowing it to work seamlessly with a wide range of bikes. With its SGS long cage, it has a chain wrap capacity of up to 45 teeth, providing ample room for a variety of gear configurations. Whether you're a casual rider or a seasoned cyclist, the Shimano Acera Rear Derailleur offers the convenience and reliability you need for a smooth and efficient ride.

What We Like
Easy installation
Smooth and quiet shifting
Wide range compatibility
Affordable price
Reliable performance
What We Don't Like
Basic design features
#TOP 6

THALOUS Bicycle Rear Derailleur for MTB Bike

TH-TY21B-G-B-US
Hanger mount-Black
Normal
THALOUS Bicycle Rear Derailleur for MTB Bike Cover
THALOUS Bicycle Rear Derailleur Tourney RD-TY21B 6 7 Speed for MTB Mountain Bike Direct Mount Hanger Mount

THALOUS Bicycle Rear Derailleur is a hook-mounted model suitable for 6-speed and 7-speed SIS index variable speed drives. It is made of high-quality steel and suitable for various types of bikes such as mountain bikes, road bikes, and city bikes. The professional customer service is available to answer any questions you may have.

What We Like
Easy installation
Affordable price
Good for kids' bikes
Strong and well-built
Fits perfectly
What We Don't Like
Lacks installation instructions
Long delivery time
#TOP 7

SunRace RDM10 Rear Derailleur

RDM10.LB00.CS0
SunRace RDM10 Rear Derailleur Cover
Sunrace Sgs Rear Friction Derailleur w/Braket: Rdm10, Silver

The SunRace RDM10 Derailleur is a friction-type rear derailleur that offers an affordable option for those looking to replace their bike component. With a wrap capacity of 35, it allows for smooth shifting across a wide range of gears, making your rides more efficient. The long cage design provides ample clearance and stability, ensuring reliable performance. Additionally, the 2-to-1 ratio enhances the shifting responsiveness, giving you better control over your bike. This derailleur is a great choice for cyclists seeking durability and ease of use.

What We Like
Affordable price
Easy installation
Compatible with older bikes
Good shifting performance
What We Don't Like
Spring tension could be stronger
Possible chain slack
#TOP 8

Relwears RD-TY21B Rear Derailleur

‎Silver-RD-TY21B-Direct Mount
6/7 Speed
Relwears RD-TY21B Rear Derailleur Cover
Bike Rear Derailleur RD-TY21B 6/7 Speed Direct Mount Derailleur for Mountain Bike Tricycle Commuter Bike Cruiser Bike

The Relwears RD-TY21B Derailleur is designed for versatility, working seamlessly with 6 and 7-speed bikes. Made from durable aluminum alloy, it ensures a reliable and smooth shifting experience, enhancing your overall ride. This derailleur is suitable for various types of bicycles, including mountain bikes, cruisers, and folding bikes, making it a great choice for different riding styles. Remember, it's a direct mount, so be sure to check your bike's compatibility before purchase. With professional support available, you can feel confident in your choice.

What We Like
Easy installation
Durable aluminum construction
Smooth shifting performance
Great value for price
Wide application across bike types
What We Don't Like
Minor compatibility checks needed
#TOP 9

Inkesky RD-TZ31-GS Rear Derailleur for Mountain Bike

703931641532
Black
Inkesky RD-TZ31-GS Rear Derailleur for Mountain Bike Cover
Inkesky RD-TZ31-GS 6/7 Speed Rear Derailleur with Direct Mount, Medium Cage, for Mountain Bike

The Inkesky RD-TZ31-GS Rear Derailleur is a medium-cage, direct mount derailleur designed for 6 and 7-speed SIS Index Shifting drivetrains on mountain bikes. With a total capacity of 34T, largest sprocket of 28T, and smallest sprocket of 14T, this derailleur is a great option for riders looking to upgrade their shifting performance. However, it is important to note that it is not compatible with hub bolt mount frames and bikes with a total capacity exceeding 34T.

What We Like
Easy installation
Cost-effective replacement
Good for basic bikes
Functional for kids' bikes
Adjustable settings
What We Don't Like
May not fit all bikes
Durability concerns
#TOP 10

MEGHNA Shimano Tourney RD-TY300 6/7-Speed Rear Derailleur

RD-TY300
Black
Standard
MEGHNA Shimano Tourney RD-TY300 6/7-Speed Rear Derailleur Cover
MEGHNA RD-TY300 6/7 Speed Rear Derailleur for Hybrid Bike Folding Bike Mountain Bike Tricycle E-Bike Direct Mount

The MEGHNA Shimano Tourney RD-TY300 6/7-Speed Rear Derailleur is a long cage tourney derailleur that is compatible with 11T/14T high speed gear and 6 and 7-speed SIS INDEX variable speed transmission systems. It features a B tension adjustment screw, so that the distance between the upper guide wheel and the tooth tip of the largest flywheel can not be less than 6mm. It is easy and fast to install and customers have reported smooth shifting and great replacement.

What We Like
Easy installation
Affordable price
Spare part availability
Smooth transaction
Effective once installed
What We Don't Like
A bit challenging to adjust
Initial tuning takes time
Buying Guide Image

A Buyer's Guide to Bike Derailleurs

Introduction

Figuring out how to choose the right bike derailleur can be a daunting task. With so many types, brands and models available, it can be hard to know which one is the best for your bike and your riding style. Fortunately, there are some key factors to consider when selecting a derailleur that will help you narrow down your choices and make the right selection.

Types of Bike Derailleurs

The first thing to consider when selecting a bike derailleur is the type of derailleur you need. There are three main types of derailleurs: front, rear, and internal.

The front derailleur moves the chain from one chainring to another, and is used for shifting between gears on a multi-speed bike. The rear derailleur moves the chain between the cogs on the cassette, and is used for fine-tuning the gear ratios for a smoother ride. Internal derailleurs are found on many modern bikes, and are a combination of the two types of derailleurs.

Components of Bike Derailleurs

Once you have determined the type of derailleur you need, the next step is to consider the components of the derailleur. The most important component is the cage, which is the metal loop that wraps around the chain, and guides it between the gears. The cage should be made of lightweight and durable material, such as aluminum or titanium.

The pulleys are the small wheels that guide the chain through the derailleur. The pulleys should be smooth and have sealed bearings to keep dirt and debris out. The pulleys should also be adjustable, so you can fine-tune the derailleur to your bike and riding style.

Another important component of the derailleur is the cage tension adjustment screw, which is used to adjust the tension of the chain. This adjustment is important for smooth shifting and reliable performance.

Finally, you should consider the shifter compatibility of the derailleur. It should be compatible with your shifter, so you can easily and reliably shift between gears.

Brands of Bike Derailleurs

Once you have considered the type, components, and shifter compatibility of the derailleur, the next step is to consider the brands available. There are several reputable brands that make high-quality derailleurs, such as Shimano, SRAM, and Campagnolo. Each brand has its own unique features and designs, so it is important to research each one to find out which one is best for your bike and your riding style.

Conclusion

Choosing the right bike derailleur can be a daunting task, but with a bit of research and consideration of the type, components, and brands available, you can make the right selection for your bike and your riding style. By taking the time to consider your options, you can ensure that you get the best possible performance from your bike.

Frequently Asked Questions (FAQs)

1. How do I know what derailleur I need?

To determine the derailleur you need, count the number of cogs on your cassette if you're replacing an existing one. If you're unsure of your drivetrain's speed, count the number of steps your shifter runs through and add one to determine the number of gears your drivetrain has.

2. What are the different types of bike derailleur?

There are several types of front derailleurs that attach to a bicycle, including clamp-on, bolt-on, and E-Type. These categories cover most front derailleurs available, each with different attachment methods and sizes.

3. Can I ride my bike without a derailleur?

Yes, it is safe to ride a bike without a front derailleur. However, riding without a front derailleur may result in more chain drops, especially off-road.

4. What is the difference between a gear and a derailleur?

The main difference between gear hubs and derailleur systems is the additional weight and price of gear hubs. Gear hubs can also be less efficient due to increased friction in the mechanism compared to a well-maintained derailleur system.

5. Will any derailleur fit my bike?

No, rear derailleurs are not interchangeable unless they are of the same model or type of bike. Not all derailleurs will fit all bikes, as the compatibility depends on factors such as cage length and bike type.

6. What is the difference between road and mountain rear derailleur?

Mountain rear derailleurs can shift larger rear cogs compared to road derailleurs. While cassettes can often be interchanged, the front derailleur needs to be matched to the road or mountain shifter. Rear derailleur matching is required for 10-speed or higher drivetrains.

7. What is the difference between 1x and 2X rear derailleur?

A 2X drivetrain has a wider gear range compared to a 1X drivetrain. It offers easier climbing gears and less of a 'spun out' experience on steep, fast descents. However, 1X drivetrains sacrifice some end-range gear capability due to having fewer gears.

Editor's Notes

During our bike derailleur research, we found 24 bike derailleur products and shortlisted 10 quality products. We collected and analyzed 48,308 customer reviews through our big data system to write the bike derailleurs list. We found that most customers choose bike derailleurs with an average price of $17.42.

The bike derailleurs are available for purchase. We have researched hundreds of brands and picked the top brands of bike derailleurs, including SHIMANO, microSHIFT, THALOUS, SunRace, Relwears. The seller of top 1 product has received honest feedback from 274 consumers with an average rating of 4.7.

Written by
Jason Kiser Avatar

Jason Kiser is an editor who lives in California, he previously worked in a travel agency for ten years, which enabled him to travel a number of interesting countries and experience several different cultures along the way. His range of job and travel experiences grant him expertise in hiking, camping, outdoors and fitness.

Bike Derailleurs Comparison Table

#TOP1
#TOP2
#TOP3
#TOP4
#TOP5
#TOP6
#TOP7
#TOP8
#TOP9
#TOP10
Brand SHIMANO SHIMANO microSHIFT SHIMANO SHIMANO THALOUS SunRace Relwears Inkesky MEGHNA
Color Black Black Black Black Black Hanger mount-Black SIL Silver-RD-TY21B-Direct Mount Black Black
Material Alloy Steel Aluminum - Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum Aluminum
Case Material - Aluminum Aluminum Aluminum Alloy Aluminum Aluminum - Aluminum Aluminum Aluminum
Item Weight 50 Grams 0.3 Kilograms - 0.01 Ounces 0.39 Kilograms - 0.61 Pounds - 203 Grams 315 Grams
Mounting Type Braze-On Mount - Braze-On Mount - - hanger-mount Clamp-On Mount Direct Mount - -
FTB Score
ftb score rating icon 9.8
ftb score rating icon 9.7
ftb score rating icon 9.5
ftb score rating icon 9.3
ftb score rating icon 9.1
ftb score rating icon 8.9
ftb score rating icon 8.8
ftb score rating icon 8.8
ftb score rating icon 8.7
ftb score rating icon 8.6
Where to Buy