Category: Mountain Bike Gears and Components When it comes to mountain biking, gearing is one of the most important aspects. The right gear ratio can make all the difference in your ability to climb steep hills, descend technical trails, and maintain speed on flat sections. That's why it's essential to have a high-quality rear derailleur that will last you for years to come. In this review, we'll take a closer look at some of the best mountain bike rear derailleurs available on the market today. We've selected 10 different models from various brands such as Shimano and SRAM, each with its own unique features and price point. So let's get started! Shimano XT RD-M8000 Rear Derailleur: The Shimano XT RD-M8000 is a top-of-the-line rear derailleur that offers excellent performance in all conditions. It features a 12-speed cassette and can handle up to a 34t chainring, making it perfect for those who want the ability to run larger gears on steep climbs. The XT RD-M8000 also has a Shadow Plus design that helps to reduce chain slap and improve shifting accuracy. Overall, this is an excellent choice for serious mountain bikers who demand the best performance possible. Tourney Shimano Rear Derailleur RD-TX35: The Tourney Shimano RD-TX35 is a mid-range rear derailleur that offers good value for its price point. It features 9 speeds and can handle up to a 28t chainring, making it suitable for most mountain biking applications. The RD-TX35 also has a long cage design that allows for wider gears on larger frames or wheels. While it may not be as durable as some of the higher-end models, it still offers good performance and is a great choice for those who want to get started in mountain biking without breaking the bank. Shimano Acera Mountain Bike Rear Derailleur: The Shimano Acera is an entry-level rear derailleur that offers excellent value for its price point. It features 8 speeds and can handle up to a 24t chainring, making it suitable for most mountain biking applications. The Acera also has a long cage design that allows for wider gears on larger frames or wheels. While it may not be as durable as some of the higher-end models, it still offers good performance and is a great choice for those who want to get started in mountain biking without breaking the bank. Shimano Tourney RD-TY300 6/7S Compatible 8S Upgraded RD-TX35: The Shimano Tourney RD-TY300 is a mid-range rear derailleur that offers good value for its price point. It features 9 speeds and can handle up to a 28t chainring, making it suitable for most mountain biking applications. The RD-TY300 also has an upgraded design over the standard Tourney TX35, with improved shifting accuracy and reduced chain slap. While it may not be as durable as some of the higher-end models, it still offers good performance and is a great choice for those who want to upgrade their existing setup without breaking the bank. SHIMANO Tourney TY500 6/7-Speed Rear Derailleur: The Shimano Tourney TY500 is an entry-level rear derailleur that offers excellent value for its price point. It features 6 speeds and can handle up to a 24t chainring, making it suitable for most mountain biking applications. The TY500 also has a long cage design that allows for wider gears on larger frames or wheels. While it may not be as durable as some of the higher-end models, it still offers good performance and is a great choice for those who want to get started in mountain biking without breaking the bank. Shimano Deore XT RD-M786 SGS Shadow Plus Rear Derailleur: The Shimano Deore XT RD-M786 is a high-end rear derailleur that offers excellent performance in all conditions. It features a 12-speed cassette and can handle up to a 34t chainring, making it perfect for those who want the ability to run larger gears on steep climbs. The XT RD-M786 also has a Shadow Plus design that helps to reduce chain slap and improve shifting accuracy. Overall, this is an excellent choice for serious mountain bikers who demand the best performance possible. SRAM X5 10 Speed Rear Derailleur: The SRAM X5 is a high-end rear derailleur that offers excellent performance in all conditions. It features a 12-speed cassette and can handle up to a 34t chainring, making it perfect for those who want the ability to run larger gears on steep climbs. The X5 also has an upgraded design over the standard Tourney TX35, with improved shifting accuracy and reduced chain slap. While it may not be as durable as some of the higher-end models, it still offers good performance and is a great choice for those who want to upgrade their existing setup without breaking the bank. Shimano Deore RD-M592 Rear Derailleur: The Shimano Deore RD-M592 is a mid-range rear derailleur that offers good value for its price point. It features 10 speeds and can handle up to a 34t chainring, making it suitable for most mountain biking applications. The M592 also has an upgraded design over the standard Tourney TX35, with improved shifting accuracy and reduced chain slap. While it may not be as durable as some of the higher-end models, it still offers good performance and is a great choice for those who want to upgrade their existing setup without breaking the bank. SRAM X.4 Rear Derailleur (Black, Long Cage): The SRAM X.4 is an entry-level rear derailleur that offers excellent value for its price point. It features 8 speeds and can handle up to a 26t chainring, making it suitable for most mountain biking applications. The X.4 also has a long cage design that allows for wider gears on larger frames or wheels. While it may not be as durable as some of the higher-end models, it still offers good performance and is a great choice for those who want to get started in mountain biking without breaking the bank. Shimano Deore XT Shadow Mountain Bicycle Rear Derailleur - RD-M772: The Shimano Deore XT Shadow RD-M772 is a high-end rear derailleur that offers excellent performance in all conditions. It features a 10-speed cassette and can handle up to a 34t chainring, making it perfect for those who want the ability to run larger gears on steep climbs. The XT RD-M772 also has an upgraded design over the standard Tourney TX35, with improved shifting accuracy and reduced chain slap. While it may not be as durable as some of the higher-end models, it still offers good performance and is a great choice for those who want to upgrade their existing setup without breaking the bank. In conclusion, when it comes to mountain biking gears and components, having a high-quality rear derailleur is essential. Whether you're a beginner or an experienced rider, there are plenty of options available on the market today that will fit your needs and budget. From entry-level models like the Shimano Acera and SRAM X.4 to top-of-the-line options like the Shimano XT RD-M8000 and SRAM X5, there's something for everyone.