Category Review: Mountain Bicycle Rear Derailleurs Mountain biking is a thrilling outdoor activity that requires a reliable and durable bicycle. One of the most important components of a mountain bike is the rear derailleur, which helps to shift gears smoothly and efficiently while riding uphill or downhill. In this review, we will be discussing some of the best mountain bike rear derailleurs available on the market today. 1. SHIMANO Deore RD-M592 Rear Derailleur: The SHIMANO Deore RD-M592 is a high-quality rear derailleur that offers excellent performance and durability. It features a long cage design, which allows for easy shifting between larger cogs, making it ideal for riders who need to tackle steep hills or technical terrain. The derailleur also has a micro shift feature, which makes fine adjustments to the gears with ease. Overall, the SHIMANO Deore RD-M592 is an excellent choice for serious mountain bikers who demand reliable performance and durability. 2. Shimano Deore 9-Speed Mountain Bicycle Rear Derailleur - RD-M591: The Shimano Deore 9-Speed Mountain Bicycle Rear Derailleur - RD-M591 is another high-quality rear derailleur that offers excellent performance and durability. It features a long cage design, which allows for easy shifting between larger cogs, making it ideal for riders who need to tackle steep hills or technical terrain. The derailleur also has a micro shift feature, which makes fine adjustments to the gears with ease. Overall, the Shimano Deore 9-Speed Mountain Bicycle Rear Derailleur - RD-M591 is an excellent choice for serious mountain bikers who demand reliable performance and durability. 3. microSHIFT MTB Mezzo Rear Derailleur RD-R45L (Long Cage): The microSHIFT MTB Mezzo Rear Derailleur RD-R45L is a high-quality rear derailleur that offers excellent performance and durability. It features a long cage design, which allows for easy shifting between larger cogs, making it ideal for riders who need to tackle steep hills or technical terrain. The derailleur also has a micro shift feature, which makes fine adjustments to the gears with ease. Overall, the microSHIFT MTB Mezzo Rear Derailleur RD-R45L is an excellent choice for serious mountain bikers who demand reliable performance and durability. 4. Shimano Deore XT Shadow Mountain Bicycle Rear Derailleur - RD-M772: The Shimano Deore XT Shadow Mountain Bicycle Rear Derailleur - RD-M772 is a high-quality rear derailleur that offers excellent performance and durability. It features a long cage design, which allows for easy shifting between larger cogs, making it ideal for riders who need to tackle steep hills or technical terrain. The derailleur also has a micro shift feature, which makes fine adjustments to the gears with ease. Overall, the Shimano Deore XT Shadow Mountain Bicycle Rear Derailleur - RD-M772 is an excellent choice for serious mountain bikers who demand reliable performance and durability. 5. SHIMANO RD-M640 Zee Shadow Plus 10 Speed Rear Derailleur: The SHIMANO RD-M640 Zee Shadow Plus 10 Speed Rear Derailleur is a high-quality rear derailleur that offers excellent performance and durability. It features a long cage design, which allows for easy shifting between larger cogs, making it ideal for riders who need to tackle steep hills or technical terrain. The derailleur also has a micro shift feature, which makes fine adjustments to the gears with ease. Overall, the SHIMANO RD-M640 Zee Shadow Plus 10 Speed Rear Derailleur is an excellent choice for serious mountain bikers who demand reliable performance and durability. In conclusion, mountain bike rear derailleurs are a crucial component of any mountain bike. When choosing a rear derailleur, it's important to consider factors such as the type of terrain you will be riding on, your skill level, and your budget. The products listed above are some of the best options available on the market today, each with its own unique features and benefits.