Shimano Deore XT RD-M8120 Dealer's Manual

Shimano Deore XT RD-M8120 Rear Derailleur manual cover
Pages 41
Year 2022
Language(s)
English en

Shimano Deore XT RD-M8120 Rear Derailleur Specification

The Shimano Deore XT RD-M8120 Rear Derailleur is engineered for mountain biking enthusiasts who demand precision and durability. This rear derailleur is designed specifically for 12-speed drivetrains and is a part of Shimano's renowned Deore XT M8100 series, which is known for its reliability and performance in rugged terrains. It features a Shadow RD+ design, which enhances stability by reducing chain slap and improving chain retention, crucial for aggressive riding on technical trails. The RD-M8120 supports a wide gear range with its ability to accommodate a maximum low sprocket of 51 teeth, making it suitable for varied terrain and steep climbs. It incorporates Shimano’s advanced technologies such as Hyperglide+ for smoother and faster shifting, even under load, ensuring seamless transitions between gears. The derailleur is constructed from high-quality materials that strike a balance between lightweight and robustness, featuring an alloy outer link and a steel inner link for enhanced durability. Its sleek design minimizes the risk of damage from obstacles on the trail, while the low-profile construction keeps it tucked away safely. Installation and adjustment are user-friendly, thanks to the optimized pulley cage design and precise tension settings. The Shimano Deore XT RD-M8120 provides a reliable and efficient shifting experience, making it an ideal choice for serious mountain bikers seeking performance and dependability.

Shimano Deore XT RD-M8120 Rear Derailleur F.A.Q.

How do I install the Shimano Deore XT RD-M8120 Rear Derailleur?

To install the RD-M8120, first attach it to the derailleur hanger using a 5mm hex key. Ensure it is properly aligned and tighten to the manufacturer's torque specifications.

What is the correct way to adjust the B-tension on the RD-M8120?

Adjust the B-tension screw to ensure the upper pulley maintains the recommended distance from the largest cassette cog for optimal shifting performance.

How can I troubleshoot shifting issues with my RD-M8120 derailleur?

Check for proper cable tension, ensure the derailleur hanger is straight, and verify that the derailleur is clean and lubricated. Adjust limit screws if necessary.

What maintenance is required for the RD-M8120 derailleur?

Regularly clean the derailleur to remove dirt and debris, lubricate the pivot points, and inspect for any signs of wear or damage.

How do I adjust the limit screws on the RD-M8120 derailleur?

Use a screwdriver to adjust the H-limit screw for the smallest cog and the L-limit screw for the largest cog, ensuring the chain does not overshift.

What should I do if the RD-M8120 derailleur is making noise?

Check for misalignment, adjust the B-tension screw, verify that the chain is properly lubricated, and ensure all bolts are tightened to spec.

Can the RD-M8120 derailleur handle a wide-range cassette?

Yes, the RD-M8120 is designed to accommodate wide-range cassettes, but make sure it's within the derailleur's specified capacity.

How do I replace the pulley wheels on the RD-M8120?

Unscrew the pulley bolts using an appropriate tool, replace the worn pulleys with new ones, and tighten the bolts securely.

What tools are needed for adjusting the RD-M8120 derailleur?

You'll need a set of hex keys, a screwdriver for limit screws, and a chain checker tool to ensure proper chain length and tension.

How can I ensure smooth shifting with my RD-M8120 derailleur?

Ensure the derailleur is properly aligned, cables are clean and lubricated, and that the chain is the correct length and condition.