The SRAM RED eTap AXS [paid link] represents the pinnacle of wireless electronic shifting in road cycling. Known for its sleek integration, intuitive setup, and cutting-edge performance, this 12-speed wireless groupset offers precise control and minimal maintenance compared to mechanical systems. However, optimal installation and regular upkeep are essential to maximize performance.
This guide walks you through the complete process of installing, adjusting, and maintaining the RED eTap AXS [paid link] drivetrain system.
Tools Required
- Torque wrench [paid link] (preset torque for SRAM components)
- 4mm and 5mm hex keys [paid link]
- T25 Torx wrench [paid link]
- Chain tool compatible with 12-speed chains
- Cassette lockring tool [paid link]
- Quick link pliers
- SRAM AXS mobile app
- Derailleur hanger alignment gauge
- Isopropyl alcohol and lint-free cloth
Understanding the SRAM RED eTap AXS System
The RED eTap AXS [paid link] system is fully wireless and includes the following core components:
- Shifters (HRD or rim brake version)
- Front and rear derailleurs
- Rechargeable batteries for each derailleur
- AXS app integration for customization and firmware updates
- 12-speed chain and cassette
- DUB [paid link] bottom bracket and RED crankset [paid link]
Each component is factory-tuned to integrate with the complete AXS ecosystem. Cross-compatibility with other SRAM AXS components is supported, but should be verified through the AXS app or SRAM’s compatibility charts.
Pre-Installation Preparation
Before starting, ensure the frame and wheels are compatible with a 12-speed drivetrain and flat-mount or post-mount brake systems, depending on your setup. Verify that the derailleur hanger is perfectly aligned to prevent indexing issues.
Clean the frame contact points with isopropyl alcohol to remove grease and debris. Check the firmware status of each component using the AXS app and update as necessary.
Installing the RED eTap AXS Shifters
Mount the shifters on the handlebar and torque to spec (6–8 Nm). Position the lever angle to suit your hand ergonomics and riding posture. Connect brake hoses or cables (if mechanical rim brakes), and bleed hydraulic disc systems using SRAM’s bleed kit [paid link] for HRD models.
Activate the shifters by installing CR2032 coin cell batteries and holding the AXS button until the LED illuminates. Pair each shifter to the appropriate derailleur using the pairing procedure detailed below.
Pairing and Configuring the System
Hold the AXS pairing button on the rear derailleur until it blinks green. Press the pairing buttons on the front derailleur and both shifters. Once all LEDs blink in unison, the system is paired.
Use the AXS app to confirm the setup, assign shifter functions, and enable sequential or compensating shift modes. You can also adjust the multi-shift rate and battery status alerts.
Installing the Derailleurs
Rear Derailleur:
Mount the derailleur to the hanger using a 5mm hex key [paid link] and torque to 8–10 Nm. Ensure the cage is free from the cassette and chain.
Front Derailleur:
Use the supplied alignment tool to set the correct height and rotation. Torque the mounting bolt to 5–7 Nm. The RED eTap AXS front derailleur [paid link] requires precise alignment to avoid rubbing and delayed shifts.
Chain Sizing and Installation
Wrap the chain around the largest front and rear cogs, bypassing the derailleur, then add two full links (one inner and one outer). Use a chain tool to trim, then install the chain with a SRAM 12-speed Flattop PowerLock quick link. Ensure the quick link is fully engaged using a master link tool.
Check that the B-gap on the rear derailleur is within the specified range using the included B-gap adjustment tool and adjust the derailleur’s B-tension screw accordingly.
Cassette and Crankset Installation
Install the RED cassette onto an XDR [paid link] driver body and torque the lockring to 40 Nm. Fit the RED crankset [paid link] onto the DUB [paid link] bottom bracket, ensuring proper spindle preload and torque values (54 Nm for the crank arm bolt).
Check chainline and front derailleur alignment once cranks and cassette are in place.
Indexing and Micro-Adjustment
While electronic shifting removes mechanical indexing, you may still need to fine-tune shift performance. Use the shifter’s micro-adjust mode:
- Press and hold the AXS button on the derailleur until it blinks.
- Use the shift paddle to incrementally move the derailleur inward or outward.
- Confirm shift smoothness under load.
Repeat the process for both front and rear derailleurs.
Battery Maintenance and Charging
Each derailleur battery lasts approximately 60 hours of ride time. Remove batteries for charging by pressing the latch and sliding upward. Fully recharge within 45 minutes using the SRAM USB charger.
Always carry a spare battery on longer rides, especially when remote or unsupported.
Firmware Updates and Customization
Open the AXS app regularly to check for firmware updates. Updates enhance shift logic, battery efficiency, and overall responsiveness. Customize shifter functions, such as assigning a single paddle to control both derailleurs (sequential mode) or customize compensation shifts during front derailleur changes.
Routine Maintenance and Cleaning
- Monthly: Clean derailleur pivots with a lint-free cloth and check battery status.
- Quarterly: Inspect derailleur hanger alignment and verify firmware versions.
- Annually: Replace chain and cassette based on wear indicators; check all torque values.
Avoid high-pressure washers. Instead, use a damp cloth and degreaser to clean components without damaging electronics.
Conclusion
Properly installing, adjusting, and maintaining the SRAM RED eTap [paid link] AXS drivetrain ensures long-term reliability, crisp shifting, and unmatched riding precision. Thanks to its fully wireless design and intuitive app integration, most mechanical concerns are simplified—if set up correctly from the start. Regular checks, micro-adjustments, and firmware updates will keep the system performing at its best.