The Shimano ST-R8025 dual control lever is part of the ULTEGRA R8020 series, designed specifically for riders with smaller hands. With a compact, ergonomic design, this lever offers precise shifting, smooth braking, and improved reach adjustment, making it ideal for road cyclists who require a comfortable and responsive control interface. Proper installation, adjustment, and maintenance ensure consistent braking, reliable shifting, and long-term durability. This guide provides step-by-step instructions on how to install, adjust, and maintain the Shimano ST-R8025 dual control lever.
Tools Required
To install and maintain the Shimano ST-R8025 dual control lever, you will need:
- 2 mm hexagon wrench
- 2.5 mm hexagon wrench
- 4 mm hexagon wrench
- 5 mm hexagon wrench
- Torque wrench[paid link]
- Shimano TL-BT03 / TL-BT03-S bleed kit
- Shimano SM-DISC oil funnel and stopper
- Shimano mineral oil[paid link]
- Isopropyl alcohol and clean rags
- Utility knife
- Shimano TL-BH61 hose tool
- Shimano TL-CT12 cable cutter
Installing the Shimano ST-R8025 Dual Control Lever
Mounting the Lever on the Handlebar
Before installing the ST-R8025 lever, ensure that the handlebar surface is clean and free of grease or debris. Proper positioning is essential for ergonomic comfort and optimal braking performance.
Loosen the lever clamp bolt using a 5 mm hexagon wrench and slide the lever onto the handlebar. The recommended position aligns the top of the lever hood with the flat top section of the handlebar. Once properly positioned, tighten the clamp bolt to 6–8 N·m using a torque wrench[paid link] to secure the lever in place.
Installing the Shifting Cable
For smooth shifting, ensure the inner cable and outer housing are in good condition. Shimano recommends using SP41 outer casing for optimal performance.
Shift to the highest gear to open the cable entry port, then insert the inner shifting cable into the hole, guiding it through the outer casing toward the derailleur. Secure the casing into the frame’s designated cable stops, ensuring there are no sharp bends or kinks that could cause shifting resistance.
If you experience inconsistent gear changes, refer to Troubleshooting Common Gear Shifting Problems on Your Road Bike for additional guidance.
Connecting the Hydraulic Brake Hose
If the brake hose is pre-installed, proceed to the bleeding process. Otherwise, follow these steps:
- Use a utility knife or Shimano TL-BH61 hose tool to cut the brake hose to the correct length. A clean, perpendicular cut prevents fluid leaks.
- Insert the olive and connector insert into the brake hose.
- Lightly lubricate the olive with Shimano mineral oil[paid link] before tightening the flare nut.
- Secure the hose into the lever port, tightening the flare nut to 5–6 N·m using a torque wrench.
At this stage, the brake system must be bled to remove trapped air and ensure consistent braking.
Adjusting the Shimano ST-R8025 Dual Control Lever
Reach Adjustment
The ST-R8025 lever is designed for riders with smaller hands, but the reach can be fine-tuned for additional comfort and control.
Using a 2.5 mm hex wrench, turn the reach adjustment screw:
- Clockwise moves the lever closer to the handlebar for a reduced reach.
- Counterclockwise increases the distance, accommodating riders with larger hands.
After adjustment, test the lever to ensure comfortable finger placement and quick braking response.
Bleeding the Brake System
Shimano recommends bleeding the hydraulic brake system if you experience spongy braking feel or inconsistent stopping power.
- Remove the bracket cover and position the bleed port screw upward.
- Use a 2.5 mm hex wrench to remove the bleed screw, then install the Shimano oil funnel.
- Fill the funnel with Shimano mineral oil[paid link] and gently pump the brake lever to release trapped air bubbles.
- Once the bubbles stop appearing, plug the funnel, reinstall the bleed screw, and clean any excess oil with isopropyl alcohol.
Maintaining the Shimano ST-R8025 Dual Control Lever
Regular maintenance of the ST-R8025 dual control lever ensures long-term reliability and optimal braking/shifting performance. Shimano recommends inspecting the lever every 5,000 km, or more frequently if riding in wet or high-stress conditions.
Replacing the Brake Fluid
Shimano mineral oil should be replaced annually or if it becomes discolored. Use the bleeding process outlined earlier to refresh the system.
Cleaning and Lubrication
To maintain smooth operation, regularly wipe down the lever body and hood with isopropyl alcohol. Avoid harsh degreasers, which may damage rubber components.
Inspect the shifting cable for fraying or wear. If shifting feels sluggish, apply Shimano SP41 grease to the cable housing.
If braking efficiency decreases, check the brake pads for wear. Worn pads should be replaced immediately to maintain stopping power.