Introduction
This manual provides essential information for the installation, operation, and maintenance of your Sram GX Eagle AXS Rear Derailleur. The Sram GX Eagle AXS system offers precise and reliable electronic shifting for an enhanced cycling experience. Please read this manual thoroughly before installation and use to ensure proper function and safety.
Package Contents
Verify that all items listed below are present in your package:
- Sram GX1 Eagle AXS 12-speed Lunar Max 52 Rear Derailleur
- Documentation (this manual)
- Note: Battery for the AXS derailleur is not included and must be purchased separately.
Setup and Installation
Proper installation is crucial for the performance and longevity of your Sram GX Eagle AXS Rear Derailleur. If you are unsure about any step, consult a professional bicycle mechanic.
Tools Required
- Hex key set (e.g., 5mm)
- Torque wrench
- Chain tool
- Sram B-gap adjustment tool (recommended for optimal setup)
- Bicycle stand
Installation Steps
- Mount the Derailleur: Securely attach the Sram GX Eagle AXS Rear Derailleur to your bicycle's derailleur hanger using the appropriate hex key. Tighten to the manufacturer's specified torque.
- Install the Chain: Route the chain correctly through the derailleur and connect it according to your chain manufacturer's instructions.
- Install AXS Battery: Insert a charged Sram AXS battery (sold separately) into the derailleur. Ensure it clicks securely into place.
- Pair with Shifter: Turn on your AXS shifter and derailleur. Press and hold the AXS button on both components until the LED flashes, then release. They should pair automatically.
- Adjust B-Gap: Use the Sram B-gap adjustment tool to set the correct distance between the upper pulley and the largest cog on your cassette. This is critical for smooth shifting.
- Set Limit Screws: Adjust the high (H) and low (L) limit screws to prevent the chain from over-shifting off the cassette.
- Micro-Adjustments: Fine-tune shifting performance using the micro-adjustment feature on your AXS shifter. Refer to the Sram AXS user guide for detailed instructions on micro-adjustments.

Image: The Sram GX Eagle AXS Rear Derailleur, showcasing its robust design and electronic components. This image illustrates the main product for installation reference.
Operation
The Sram GX Eagle AXS system provides intuitive electronic shifting.
Shifting
- Upshift: Press the designated upshift button on your AXS shifter to move the chain to a smaller cog (harder gear).
- Downshift: Press the designated downshift button on your AXS shifter to move the chain to a larger cog (easier gear).
- Multi-Shift: Some AXS shifters allow for multi-shifting by holding down a button. Refer to your shifter's manual for specific settings.
Battery Status
The LED indicator on the derailleur provides information about the battery charge level:
- Green LED: Full to high charge.
- Red LED: Low charge.
- Flashing Red LED: Very low charge, recharge immediately.
Maintenance
Regular maintenance ensures optimal performance and extends the lifespan of your derailleur.
- Cleaning: Keep the derailleur, jockey wheels, and chain clean from dirt and debris. Use a mild degreaser and brush, then rinse and dry thoroughly.
- Lubrication: Lubricate your chain regularly with appropriate chain lubricant. Avoid getting lubricant on the derailleur body or battery contacts.
- Inspection: Periodically inspect the derailleur for any signs of damage, loose bolts, or excessive wear on the jockey wheels. Replace worn parts as needed.
- Battery Care: Keep battery contacts clean and dry. Store batteries in a cool, dry place when not in use.
- Firmware Updates: Use the Sram AXS app to check for and install any available firmware updates for your derailleur.
Troubleshooting
Here are some common issues and their potential solutions:
- Shifting is sluggish or inconsistent:
- Check battery charge level.
- Verify B-gap adjustment.
- Ensure limit screws are correctly set.
- Check for bent derailleur hanger.
- Clean and lubricate the drivetrain.
- Derailleur not responding to shifter:
- Confirm battery is charged and properly installed.
- Re-pair the derailleur with the shifter.
- Check for any physical obstructions preventing movement.
- LED on derailleur is flashing red rapidly:
- Battery is critically low. Recharge or replace the battery immediately.
Specifications
| Feature | Detail |
|---|---|
| Brand | Sram |
| Model Number | 2137901199 |
| Product Dimensions | 21L x 21W x 10H cm |
| Item Weight | 830 g (1.83 lbs) |
| Material | Steel Alloy |
| Color | Black |
| Mounting Type | Braze-on Mount |
| Sport | Cycling |
Warranty and Support
For detailed warranty information, technical support, and service inquiries, please visit the official Sram website or contact your authorized Sram dealer. Keep your proof of purchase for warranty claims.
Official Sram Website: www.sram.com





