Rear derailleurs (MTB)

Mountain bike derailleurs are central components of a bicycle's drivetrain and play a crucial role in precise and efficient gear shifting. They ensure that the chain moves smoothly between the different cogs on the cassette, adjusting the gear ratio to suit the terrain. There are various types of derailleurs, developed for different riding styles and uses, with renowned manufacturers like Shimano and SRAM dominating the market.

A mountain bike derailleur consists of several parts, including the cage, jockey wheels, derailleur arm, and spring. The cage keeps the chain tensioned and guides it over the cassette's cogs. Modern derailleurs often feature "Shadow Plus" technology (from Shimano) or "Type 2" technology (from SRAM), which minimizes chain slap and ensures more stable shifting performance on rough terrain. These technologies are particularly advantageous during bumpy descents, as they help keep the chain stable and prevent it from dropping.

Mountain bike derailleurs come in various configurations, depending on the number of gears (e.g., 10, 11, or 12-speed). High-end derailleurs like the Shimano XT or SRAM GX Eagle are known for their precise shifting and offer a wide gear range. These derailleurs are ideal for demanding riders who need to tackle both steep climbs and fast descents. The latest models often feature a 1x12 drivetrain, which eliminates the front derailleur, reducing weight while still providing a broad gear range.

To extend the lifespan of a derailleur, regular maintenance is essential. This includes cleaning the jockey wheels and adjusting the derailleur to ensure smooth shifting. High-quality derailleurs are made from durable materials like aluminum or carbon, making them more robust and long-lasting.

Mountain bike derailleurs are thus crucial components that significantly contribute to a bike's performance and control.

Key manufacturers of mountain bike derailleurs include SRAM, Shimano, and microSHIFT.