Best Rear Bike Derailleurs for Mountain Bikes of 2025

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.

The Huazu Bike Parts Gear Shifter for Shimano RD-TZ31-A is a durable and reliable rear derailleur that is compatible with GS 6/7 speed SIS Index Shifting drivetrains. Made with a combination of aluminum alloy and plastic alloy materials, this derailleur provides excellent shifting performance and ensures safe and stable riding. With a total capacity of 34T, largest sprocket of 28T, smallest sprocket of 14T, and front chain wheel tooth difference of 20T, this derailleur is suitable for mountain bikes, road bikes, folding bicycles, and more. Please note that this derailleur is direct mount, not hub bolt mount, so be sure to check the mount type of your original part before ordering.

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.

The Huazu Altus Rear Derailleur is designed for 7/8 speed bikes, offering a reliable performance for mountain and road cyclists. Its wide link design enhances durability and ensures smooth, precise shifting, allowing you to change gears effortlessly during your rides. The large guide wheel minimizes noise and reduces wear, making your biking experience quieter and more enjoyable. With a maximum rear sprocket capacity of 34T and a total capacity of 43T, this derailleur is versatile enough for various biking needs. The direct mount feature makes installation easy, so you can spend more time riding and less time on maintenance.

The Huazu Rear Derailleur is designed for optimal performance with a long cage that can handle a 34T cassette, giving you the flexibility you need for various terrains. Its durable aluminum alloy construction ensures longevity while also reducing weight, which is essential for a smoother ride. With SIS Index Technology and a Double Servo-Panta Mechanism, shifting becomes effortless, allowing you to focus on enjoying your ride. Additionally, it is compatible with both 6 and 7-speed systems, ensuring precise and reliable shifting, making it a great choice for mountain, road, and touring bikes.

The Relwears RD-TX800 Derailleur is designed for 8-speed bicycles, ensuring smooth and reliable gear shifting. Before purchasing, you can easily check if it fits your bike with its direct installation feature. This derailleur is versatile, making it suitable for various bike types, including mountain, road, and folding bikes, enhancing your riding experience. With a proven durability after extensive testing, it remains robust even after 50,000 kilometers, allowing you to enjoy precise gear adjustments. You can feel confident knowing that excellent customer support is available for any questions you may have.

The Relwears RD-TY300 Derailleur is designed for 6 and 7-speed bikes, making it compatible with various types like mountain, hybrid, and road bikes. Its easy installation feature allows you to quickly set it up, so you can spend more time riding. With a long cage design, it supports a total capacity of 43T, ensuring smooth gear changes during your rides. Made from durable aluminum alloy, this derailleur provides excellent shifting performance, enhancing your riding stability and safety on different terrains.

The Relwears RD-TZ31A Derailleur is designed for 6/7 speed bikes, offering exceptional stability thanks to its durable aluminum alloy construction. This ensures a safe and smooth ride. You’ll appreciate the precise adjustments possible with its high-hardness body, allowing you to fine-tune your gear shifts effortlessly. The guide wheel, made from PA nylon and aluminum alloy, operates quietly and smoothly, minimizing chain wear. Additionally, installation is quick and easy, making maintenance a breeze. This derailleur is a great choice for mountain bikes, tricycles, and cruisers, enhancing your cycling experience.

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.

The Relwears RD-TY21B Derailleur is designed for compatibility with 6 and 7-speed bikes, making it a versatile choice for various cycling needs. Its durable aluminum alloy construction ensures long-lasting performance and reliable shifting, enhancing your riding experience. Whether you ride a mountain bike, commuter bike, or cruiser, this derailleur performs exceptionally well, providing smooth gear transitions. Additionally, it features a hanger mount design, which allows for easy installation, ensuring you can quickly get back on the road. With this derailleur, you can enjoy a safer and more stable ride.