How to Adjust Rear Derailleur
The rear derailleur is crucial for smooth gear shifting. Learn how to adjust it without hassle. This guide will walk you through the process step-by-step.
Tools Needed
- Bicycle stand or a way to elevate the rear wheel
- Phillips and flathead screwdrivers
- 5mm Allen wrench
- Chain lubricant
- Clean cloth
Inspect the Derailleur
Before making adjustments, check the derailleur. Look for visible damage or dirt buildup.
Inspect the derailleur hanger. Ensure it is straight. If it’s bent, replace or straighten it.
Check Cable Tension
Shift the bike to the smallest chainring and smallest rear cog. This provides a relaxed cable to work with.
Inspect the cable for fraying or rust. Replace if necessary.
Adjust the Limit Screws
High-Limit Screw
Locate the high-limit (H) screw. This screw prevents the chain from shifting beyond the smallest cog.
Shift to the smallest cog. Pedal by hand if using a stand. Use the H screw to align the top pulley with the smallest cog.
Low-Limit Screw
Shift to the largest cog using the barrel adjuster. Locate the low-limit (L) screw. This screw prevents the chain from shifting beyond the largest cog.
Use the L screw to align the top pulley with the largest cog. Make precise adjustments. Small turns can make a big difference.
Indexing Adjustment
Shift to the middle gear. Pedal by hand and shift through gears. Listen for hesitation or chain noise.
If gears don’t shift smoothly, adjust the barrel adjuster. Turn it clockwise for tighter cable tension, counter-clockwise for looser.
Test each gear. Fine-tune with the barrel adjuster until shifts are smooth.
B-Screw Adjustment
The B-screw controls the distance between the derailleur and the cassette. This affects the shifting quality on larger cogs.
Locate the B-screw. It’s near the derailleur mounting bolt.
Shift to the largest cog. Observe the distance between the top pulley and the cog.
Turn the B-screw to adjust. Clockwise moves the pulley closer, counter-clockwise moves it away. Aim for a 5-6mm gap.
Lubricate the Chain
Apply lubricant to the chain for smooth operation. Rotate the pedals backward, applying lube evenly.
Wipe off excess with a clean cloth. A properly lubricated chain reduces wear on the derailleur.
Test Ride
Take a short ride to test your adjustments. Shift through all gears under load.
Listen and feel for smooth transitions. If issues remain, revisit the steps. Pay close attention to cable tension and limit screw settings.
Adjusting the rear derailleur is a skill that improves with practice. Take your time and make adjustments carefully. Keep your tools handy and ensure regular maintenance for optimal performance.