Rear Derailleur Adjustment DIY: No More Chain Skipping and Noise

Three Screws Solve 80% of Your Shifting Problems

“Tick-tick-tick-tick” - if your bike makes this regular metallic clicking sound while riding, or certain gears just won’t shift into properly, don’t rush off to the bike shop. Adjusting a rear derailleur really isn’t as hard as you might think.

Getting to Know the Rear Derailleur’s Three Key Screws

There’s also something that isn’t a screw but is just as important: the barrel adjuster, usually found on the shift lever or the rear derailleur itself.

Step 1: Check the Derailleur Hanger

Before you touch any screws, look at your rear derailleur from behind the bike. The upper and lower pulleys should line up in a straight line, perpendicular to the ground. If they’re crooked, your derailleur hanger may be bent.

A bent hanger is the number one cause of poor shifting. This can’t be fixed with screw adjustments - it needs to be straightened with a dedicated tool or simply replaced.

Step 2: Adjust the H Limit Screw

Purpose: Make sure the chain doesn’t fall off the outside of the cassette when on the smallest cog.

1. Shift to the smallest cog (hardest gear)
2. Release cable tension
3. Looking from behind the bike, the upper and lower pulleys should align with the outer edge of the smallest cog
4. Turning the H screw clockwise = pulleys move inward
5. Turning the H screw counterclockwise = pulleys move outward

Step 3: Adjust the L Limit Screw

Purpose: Make sure the chain doesn’t fall into the wheel on the largest cog (this is dangerous!).

1. Shift to the largest cog (easiest gear)
2. Looking from behind the bike, the upper and lower pulleys should align with the inner edge of the largest cog
3. Adjust the same way: clockwise moves inward, counterclockwise moves outward

Step 4: Adjust the B-Tension Screw

Purpose: Controls the distance between the upper guide pulley and the cassette.

With the chain on the largest cog, the gap between the upper pulley and the cassette teeth should be about 5-6mm. Too close causes chain skipping; too far makes shifting sluggish.

Step 5: Fine-Tune Cable Tension

This is the part that most often needs adjusting, and it’s the key to fixing everyday shifting noise.

Key point: Turn only 1/4 to 1/2 turn at a time, then test. Don’t turn too much at once.

Common Mistakes

1. Adjusting cable tension before setting the limit screws: Make sure the limits are correct first, then adjust cable tension
2. Forgetting to check the hanger: If the hanger is bent, no amount of adjustment will fix it
3. Water or rust inside the cable housing: No adjustment can truly fix this - it’s time to replace the cable
4. Chain too long or too short: This also affects shifting quality

When Should You Go to a Bike Shop?

• The hanger is confirmed bent
• The shift cable or housing needs replacing
• The rear derailleur body is damaged or badly worn
• You’ve tried adjusting for a while and still can’t get it right (that’s okay, it’s normal)

Tool Checklist

Once you’ve learned to adjust your rear derailleur, you’ll find you’re no longer bothered by that “tick-tick-tick” noise while riding. And next time you’re at the bike shop, you can proudly say: “I can adjust this myself.”

Related Reading

• Shifting Adjustment DIY: Fine-Tuning Steps for Front and Rear Derailleurs
• Inspecting and Replacing Your Bike’s Derailleur Hanger
• Rear Derailleur Adjustment Masterclass: Master Precise Shifting From Scratch
• Road Bike Drivetrain Adjustment: Fine Calibration of Front and Rear Derailleurs