RED eTap Limit Screw Adjustments: How to Get Them Just Right

Posted on
in No category

When working with the SRAM RED eTap [paid link] drivetrain, precise adjustments are crucial to ensuring smooth shifting and optimal performance. One of the key elements of achieving flawless shifting is setting the limit screws correctly. These screws prevent the derailleur from overshooting the cog set, which could cause chain dropping or shifting issues. This guide provides an expert-level [paid link] explanation of how to adjust the limit screws on your RED eTap [paid link] derailleur, helping you get the most out of your system.

Understanding the Importance of Limit Screws

The limit screws on your SRAM RED eTap [paid link] derailleur serve as physical boundaries that prevent the derailleur from shifting too far in either direction. There are two limit screws:

  • High limit screw (H-screw): Controls how far the derailleur can move towards the smallest cog.
  • Low limit screw (L-screw): Controls how far the derailleur can move towards the largest cog.

Correctly adjusting these screws ensures that your derailleur operates within the range of the cassette without causing any damage or erratic shifting behavior.

Tools Required

  • 2mm or 3mm Allen wrench [paid link]
  • Screwdriver (flathead or Phillips, depending on the screw type)
  • Bike stand [paid link] for stability
  • Chain checker (optional for checking chain wear)

Step-by-Step Guide to Adjusting the Limit Screws on Your SRAM RED eTap

1. Set the Chain to the Smallest Cog

Before adjusting the limit screws, set your bike in the small chainring and the smallest cog. This position minimizes the tension on the derailleur and gives you a stable starting point for adjustments.

2. Inspect the Derailleur Position

Check that the derailleur is aligned properly with the cog set. The derailleur should be positioned straight with the cogs, and the jockey wheels should align with the cassette. If your derailleur is slightly misaligned, it could affect the shifting performance, even if the limit screws are correctly adjusted.

3. Adjust the High Limit Screw (H-Screw)

The high limit screw prevents the derailleur from shifting beyond the smallest cog, which could cause chain drop or derailleur damage.

  • Use the 2mm or 3mm Allen wrench [paid link] to turn the high limit screw.
  • Turn the screw clockwise to move the derailleur towards the frame, limiting the movement toward the smallest cog.
  • Turn the screw counterclockwise to allow the derailleur to move further out towards the cog.
  • While adjusting, shift through your gears to ensure the derailleur does not overshoot into the frame or drop the chain.

4. Adjust the Low Limit Screw (L-Screw)

The low limit screw controls the derailleur’s movement towards the largest cog. If the derailleur overshoots and moves into the spokes or drops the chain, the low limit screw is too loose.

  • Again, using your Allen wrench [paid link], turn the low limit screw.
  • Turn it clockwise to limit the derailleur’s movement towards the large cog.
  • Turn it counterclockwise to allow the derailleur to shift further into the cog set.
  • Shift to the largest cog and ensure that the derailleur does not shift beyond the cassette. You should be able to shift smoothly without the chain dropping or the derailleur skipping.

5. Test Shifting Across All Gears

Once both the high and low limit screws are adjusted, go through the entire gear range, shifting up and down the cassette. Pay close attention to the shifting performance, especially when transitioning to the smallest and largest cogs. If the derailleur does not properly engage the gears or overshoots, return to the respective limit screw and fine-tune the adjustments.

6. Check for Chain Line and Smooth Shifting

After completing the adjustments, check that the chain line is straight when in the middle gears of the cassette. This ensures that the drivetrain is properly aligned, which will reduce wear and improve shifting precision.

Common Issues with Limit Screw Adjustments

  • Skipping or missed shifts: If your derailleur is not reaching the correct cog or skipping gears, the limit screws might not be correctly set, or the derailleur hanger could be bent. Always check the derailleur hanger alignment before adjusting the screws.
  • Chain drops: A chain drop on the smallest cog or largest cog can result from either the high or low limit screw being too loose. Always double-check that the screws are tightened correctly.
  • Jockey wheels not aligned with the cogs: If the derailleur is misaligned, adjust the hanger or ensure the derailleur is mounted correctly to prevent shifting issues.

Conclusion

Properly adjusting the limit screws on your SRAM RED eTap derailleur is crucial for maintaining smooth, reliable shifting performance. By following the steps outlined above, you can ensure that your derailleur operates within the ideal range, preventing issues like chain drops or erratic shifting. With regular maintenance and attention to detail, your SRAM RED eTap system will deliver optimal performance for years to come.