How to Install, Adjust, and Maintain the Shimano RD-5800 Rear Derailleur

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in 105, Rear Derailleur, Shimano

The Shimano RD-5800 [paid link] rear derailleur is a key component of Shimano’s 105 groupset, designed to provide precise and smooth shifting across an 11-speed cassette. Whether you’re upgrading, replacing, or fine-tuning your setup, proper installation and maintenance are crucial for peak performance.

In this guide, we’ll cover everything you need to know about installing, adjusting, and maintaining the RD-5800 [paid link] rear derailleur. By following these steps, you’ll ensure crisp, responsive shifting and extend the lifespan of your derailleur.

Tools Required [paid links]

Before starting, gather the following tools:

Step 1: Installing the Shimano RD-5800 Rear Derailleur

1.1. Mounting the Derailleur

  1. Shift the chain onto the smallest rear cog and remove the old derailleur if replacing one.
  2. Align the RD-5800 [paid link]’s hanger bolt with the rear derailleur hanger on the bike frame.
  3. Use a 5mm Allen key to tighten the derailleur onto the hanger. Torque the bolt to 8-10Nm to prevent overtightening or loosening over time.

1.2. Routing and Securing the Cable

  1. If replacing the cable, insert a new shift cable through the shifter housing and pull it through until it emerges near the derailleur.
  2. Guide the cable under the RD-5800’s cable clamp bolt and ensure it follows the proper cable path.
  3. Hold the derailleur in its relaxed position (smallest cog) and tighten the cable clamp bolt securely.

1.3. Checking Chain Length

  1. Wrap the chain around the largest front chainring and largest rear cog, bypassing the derailleur.
  2. Add two extra links for the correct chain length, then cut and connect the chain using a chain tool.
  3. Ensure the chain runs smoothly through the jockey wheels without excessive slack.

Step 2: Adjusting the Shimano RD-5800 Rear Derailleur

2.1. Setting the High (H) Limit Screw

  1. Turn the high limit (H) screw until the upper jockey wheel aligns directly under the smallest cog.
  2. Shift to the smallest cog and rotate the cranks to ensure the chain moves smoothly without overshifting.

2.2. Setting the Low (L) Limit Screw

  1. Shift to the largest cog and check alignment with the upper jockey wheel.
  2. Adjust the low limit (L) screw to center the jockey wheel under the largest cog.
  3. Avoid excessive tension, as it can restrict movement and cause skipping.

2.3. Adjusting B-Tension for Optimal Performance

  1. The B-tension screw controls the gap between the guide pulley and the largest cassette cog.
  2. Increase tension if shifting feels sluggish in larger cogs, or decrease it if the derailleur struggles with smaller cogs.
  3. The ideal gap is 5-6mm for the RD-5800.

2.4. Fine-Tuning Index Shifting

  1. Shift through all gears to test smoothness.
  2. If shifting is slow moving to larger cogs, slightly increase cable tension using the barrel adjuster.
  3. If shifting skips or hesitates, slightly reduce cable tension.

Step 3: Maintaining the Shimano RD-5800 Rear Derailleur

3.1. Cleaning and Lubrication

  1. Use a degreaser and a clean rag to wipe down the derailleur body, jockey wheels, and pivots.
  2. Apply a small amount of lubricant to the pivot points to maintain smooth movement.
  3. Avoid over-lubricating the jockey wheels to prevent attracting dirt.

3.2. Checking for Wear and Damage

  1. Inspect the jockey wheels for excessive wear and replace them if teeth appear worn down.
  2. Check the derailleur hanger for bends or misalignment using a derailleur hanger alignment tool.
  3. Inspect the shift cable for fraying or corrosion and replace if necessary.

3.3. When to Replace the RD-5800 Derailleur

  1. If the derailleur struggles to hold indexing adjustments, internal pivot wear may require replacement.
  2. Excessive side-to-side play in the jockey wheels is another indicator of wear.
  3. If the derailleur is bent or cracked from impact, it should be replaced immediately.

Troubleshooting Common RD-5800 Issues

4.1. Poor Shifting Performance

  • Check for cable tension issues and adjust using the barrel adjuster.
  • Ensure the derailleur hanger is straight by using an alignment tool.

4.2. Chain Skipping on Gears

  • Verify that limit screws are correctly adjusted.
  • Check for stretched or worn-out chains and replace them if necessary.

4.3. Excessive Noise While Shifting

  • Inspect and clean the jockey wheels for debris buildup.
  • Ensure the B-tension adjustment is set correctly to prevent rubbing.

Conclusion

The Shimano RD-5800 rear derailleur is a reliable, high-performance component when installed and maintained correctly. Regular adjustments, proper lubrication, and monitoring for wear will keep your shifting crisp and precise.