The Shimano Ultegra ST‑R8160 TT brake/shift levers are built with time trial and triathlon performance in mind. However, their inclusion in gravel setups is becoming more common due to their aerodynamic design, lightweight composition, and integrated electronic Di2 shifting. In this guide, we’ll examine how these brake sets perform on gravel terrain, with detailed instructions for installation, adjustment, and troubleshooting. We’ll also explore compatibility, potential for customization, and compare the ST‑R8160 to similar models.
Tools Required
- 4mm and 5mm Allen wrenches [paid link]
- Torque wrench
- Shimano Di2 E-Tube app or PC software
- Shimano hydraulic brake bleed kit
- Mineral oil (Shimano-specific)
- Clean rag and isopropyl alcohol
- Internal routing tools (for aero [paid link] bar setups)
- Cable cutters
Installation Procedure of Ultegra ST‑R8160 TT on Gravel Bikes
While the ST‑R8160 was designed primarily for TT bars, some gravel riders integrate it into custom aero cockpit setups. Installation requires attention to internal cable routing and Di2 port configuration.
Start by identifying your handlebar’s internal routing path. The lever bodies are narrow, so fitting them on gravel drop bars isn’t ideal; instead, riders using aero clip-on bars or mono-extensions can integrate them smoothly. Attach the levers using the 4mm Allen bolts, ensuring alignment for optimal brake reach.
The integrated Di2 wire connections should be inserted carefully to avoid damage. Use Shimano’s E-Tube wiring with secure grommets to minimize movement inside the bars. Connect the shift levers to a central junction box (either A or B type, depending on your Di2 generation).
Brake line connection is straightforward. Use Shimano’s hydraulic hose (SM-BH90-JK-SSR) and trim to length before connecting with olive and insert. Torque all connections to Shimano’s specification and check for tightness.
Brake and Shift Adjustment for Gravel Conditions
Fine-tuning brake engagement and Di2 response is crucial when using the ST‑R8160 on rugged terrain. Gravel routes introduce variability in grip, so responsiveness must be exact.
Start by adjusting lever reach with the integrated reach adjust bolt. This allows gravel riders to optimize modulation and comfort, especially when encountering rough descents. Set the reach so braking pressure is consistent with minimal hand fatigue.
Di2 shifting should be programmed using the Shimano E-Tube Project app. You can customize shift speed, multi-shift, and button functions. Gravel-specific programming includes assigning easier gear access to the outer lever for fast climbing adjustments.
Hydraulic brake pressure can be optimized by inspecting the bite point and ensuring no sponginess exists. Conduct a brake bleed if engagement feels inconsistent. Shimano recommends a full bleed after initial setup to eliminate any trapped air caused during hose trimming.
Routine Maintenance of ST‑R8160 TT Brake Levers on Gravel Bikes
Dust, mud, and vibration make gravel terrain especially tough on brake systems. The ST‑R8160 levers must be cleaned regularly, particularly around the Di2 ports and hydraulic interfaces.
Wipe down the lever bodies after each ride using isopropyl alcohol to remove grime. Check for brake fluid leakage or seepage around the reservoir cap. Inspect Di2 wires for stress or pinching—this is common when bars flex under load.
Every 1,500–2,000 km, inspect the hydraulic lines for wear or damage. Perform a fluid flush and brake bleed using Shimano mineral oil [paid link]. You should also test Di2 button responsiveness—gravel impacts can occasionally misalign the internal contacts, especially if integrated with third-party bar ends or extensions.
Common Set-Up Issues and Troubleshooting
Despite their performance, ST‑R8160 levers can encounter specific issues when used in gravel conditions.
Issue 1: Brake Lever Pulsing or Spongy Feel
This is typically due to incomplete hydraulic bleeding or air trapped near the caliper. Re-bleed the system while rotating the caliper to its highest position during service.
Issue 2: Intermittent Di2 Shifting
Inspect E-Tube wiring for loose connections. If wires are routed internally, vibrations from gravel can cause micro-disconnections. Re-seat all connectors and test with the E-Tube app.
Issue 3: Lever Misalignment
If mounted on clip-on aero extensions, the ST‑R8160 can shift slightly under load. Check torque settings on the mounting bolts and consider using a thread-locking compound for improved retention.
Customization and Performance Optimization
Gravel riders often demand non-traditional setups, and the ST‑R8160 can be adapted with a few tweaks.
You can reassign shift buttons to suit riding preference. For example, assign the right lever for front shifting and the left for rear shifting to mimic MTB-style ergonomics. Use E-Tube customization to adjust shift behavior, especially if paired with the GRX rear derailleur for more range.
Add satellite shifters (SW-RS801-S or similar) on bar tops or drops for alternative gear access during climbs or technical descents. This can significantly enhance control during rapid terrain changes.
Hydraulic lever feel can also be tuned using different pad compounds. For instance, finned metallic pads offer more consistent braking on descents, but resin pads provide quieter operation over long gravel rides.
Model Comparison: ST‑R8160 vs ST‑6871 (Ultegra Di2 TT)
When considering gravel use, comparing the ST‑R8160 with its predecessor, the ST‑6871, offers clarity.
| Feature | ST‑R8160 | ST‑6871 |
|---|---|---|
| Brake Type | Hydraulic Disc | Rim Brake |
| Shifting | Di2 Only | Di2 Only |
| Ergonomics | Slimmer Profile | Bulkier |
| Gravel Suitability | High (with mod) | Low |
| Button Customization | Enhanced | Limited |
The ST‑R8160 excels in hydraulic integration and shift customization, making it far more suitable for modern gravel builds than the ST‑6871.
Compatibility with Drivetrain Components
ST‑R8160 levers are Di2-specific and must be used with electronic derailleurs. While marketed within the Ultegra R8100 series, they are fully compatible with GRX Di2 RD-RX815 rear derailleurs, making them ideal for gravel 1x or 2x systems.
Ensure you’re using the 12-speed Di2 platform. These levers will not function with mechanical components or older 11-speed Di2 systems without firmware issues or signal mismatches. The central junction box must also be updated to match 12-speed protocols.
FAQs
1. Can the ST‑R8160 be used with drop handlebars?
Not traditionally. These are designed for bar-end or aero extensions. Creative mounting is required for drop bars and may reduce ergonomic efficiency.
2. Is the ST‑R8160 compatible with mechanical drivetrains?
No. It is Di2-specific and only compatible with Shimano’s electronic derailleurs.
3. Can I bleed the brakes without removing the levers?
Yes, but it’s easier and cleaner to access the bleed port with the levers removed from the bars.
4. Are these levers suitable for 1x gravel setups?
Yes. Pair with a GRX Di2 derailleur and cassette for optimal performance in a 1x configuration.
5. Do I need a Junction A box to run these levers?
Yes, you need a central junction point to distribute Di2 signals, typically mounted under the stem or inside the frame.
6. What type of handlebars work best with these levers on gravel bikes?
Clip-on aero bars or mono-extensions offer the best integration, particularly for long-distance gravel or bikepacking setups.
Conclusion
While unconventional, integrating the Shimano Ultegra ST‑R8160 TT brake levers into gravel bike setups offers substantial performance benefits—particularly for riders focused on speed, aerodynamics, and precision shifting. With proper setup and thoughtful customization, they provide reliable braking and flawless shifting even in unpredictable off-road environments.