Shimano Ultegra ST-R8170-L Di2 Left Shifter/Disc Brake Lever – Wireless Precision, Pro-Level Control
Built for seamless front shifting and high-performance braking, the Shimano Ultegra ST-R8170-L brings next-gen Di2 wireless technology and refined modulation to your left-hand controls.
As part of Shimano’s 12-speed ULTEGRA R8100 series, this left-side Dual Control Lever offers ultra-fast, wireless Di2 front shifting in a sleek, aerodynamic package. SERVO WAVE action delivers rapid pad engagement followed by smooth, progressive braking—perfect for confident cornering and steep descents.
With input from pro riders, the hood profile has been raised and reshaped for enhanced grip and ergonomic comfort, no matter your riding style. It's also compatible with SD300 satellite shifters and customisable via the Shimano E-Tube Project App for tailored performance and setup flexibility.
Key Features:

Left-hand 12-speed Dual Control Lever for Di2 front shifting and hydraulic disc braking
Wireless Di2 connectivity ensures fast, clean, and reliable performance
SERVO WAVE technology provides quick pad contact and controlled brake modulation
Ergonomic lever design with raised hood peak for improved grip and comfort
Compatible with Shimano E-Tube Project App for personalisation and firmware updates
Supports SD300 satellite shifter integration for cockpit customisation
Uses Shimano Mineral Oil with funnel bleed compatibility
Long-lasting CR1632 coin cell battery offers 1.5–2 years of typical use
Reach and free stroke adjust for a tailored fit

Technical Specifications:

Model: ST-R8170-L (Left Side Only)
Series: Shimano ULTEGRA R8100
Speeds: 12-speed (front shifting)
Shifter Type: Dual Control Lever (Di2 Electronic)
Brake Compatibility: Hydraulic disc, recommended with BR-R8170 caliper
Brake Hose: SM-BH90-JK-SSR (straight joint, black)
Oil Type: Shimano Mineral
Clamp Diameter: 23.8–24.2 mm
Connectivity: Wireless and wired Di2
Satellite Shifter Ports: 1x SD300
SD300 Port Count: 1
Battery: CR1632 (user-replaceable)
Firmware Updates: Via Shimano E-Tube Project
Reach Adjust: Yes (with bolt)
Free Stroke Adjust: Yes
Average Weight: Approx. 195 g (left side only; total pair weight: 391 g)
Funnel Bleed Compatible: Yes