How to Adjust Rear Derailleur

Introduction

Adjusting the rear derailleur on your bike ensures smooth and accurate gear shifts. It’s a valuable skill for any cyclist and can extend the lifespan of your drivetrain. Here’s how you can adjust the rear derailleur step by step.

Tools You’ll Need

• Phillips or flathead screwdriver
• 5mm Allen wrench
• Bike stand or alternative support
• Lubricant
• Clean rag

Preliminary Checks

Before you start, make sure your bike is clean. Wipe down the derailleur and the chain with a clean rag. Lubricate the chain if necessary. Inspect the derailleur hanger to ensure it’s not bent. If bent, you’ll need to straighten it or have it replaced.

Gear and Cable Check

Shift to the smallest rear cog and the largest front chainring. Check the condition of the derailleur cable and housing. If frayed or rusty, replace them. A deteriorated cable can hinder smooth shifting.

Adjust Limit Screws

High Limit Screw

Locate the high-limit screw marked with an H. This screw controls the stopping point for the smallest cog. Use a screwdriver to adjust it. Make sure the jockey wheel is aligned with the smallest cog. Turn clockwise to move it inward and counterclockwise to move it outward.

Low Limit Screw

Shift to the largest rear cog. Locate the low-limit screw marked with an L. This screw controls the stopping point for the largest cog. Adjust it so the jockey wheel aligns with the largest cog. Turn clockwise to move it inward, counterclockwise to move it outward.

Adjust Barrel Adjuster

Move the chain to the middle of the cassette. The barrel adjuster fine-tunes the cable tension. Turn the adjuster counterclockwise to increase tension, clockwise to decrease. Shift through the gears and listen for any skipping. Fine-tune until the shifting is smooth and prompt.

Indexing Adjustment

Shift through each gear, both up and down. The derailleur should move smoothly from one cog to the next. If it hesitates or skips, adjust the barrel adjuster slightly. Repeat until shifting is consistent.

B-Screw Adjustment

The B-screw adjusts the distance between the top jockey wheel and the cogs. Shift to the largest cog. Use the Allen wrench to turn the B-screw. Adjust until there’s a gap of about 5-6mm between the top jockey wheel and the cog. This ensures efficient shifting in all gears.

Final Test Ride

Take your bike for a test ride. Shift through all the gears to ensure everything is working correctly. Listen for any unusual noises or skipping. Make any final adjustments as needed to perfect the shifting.

Maintenance Tips

• Regularly check the derailleur alignment
• Keep the drivetrain clean and lubricated
• Inspect cables and housing for wear
• Have a professional check the setup periodically

“`