The Shimano Ultegra ST-R8170 right STI lever brings race-proven wireless Di2 shifting and precise hydraulic disc braking into the mid-range tier — delivering performance that rivals DURA-ACE at a more accessible price. Redesigned ergonomics, Servo Wave brake technology, and fully wireless connectivity make this lever an exceptional upgrade for road and endurance riders who demand the best from every kilometre.

Highlights

• Wireless Di2 electronic shifting — no wires required between lever and derailleurs
• SERVO WAVE hydraulic braking for rapid initial pad contact and progressive modulation
• 12-speed rear shift control, compatible with the Ultegra R8100 groupset
• CR1632 coin cell battery with 1.5–2 years typical life, swappable in under a minute
• 16.4 mm reach adjustment range to suit a wide range of hand sizes
• Three programmable switches for customisable shifting and function assignment via E-Tube Project app
• Compatible with satellite shifters (SW-RS801, SW-RS802) for tri/TT bar mounting
• Carbon (CFRP) brake lever blade for low weight and excellent feel

Wireless Di2 Platform

The ST-R8170 uses Shimano's latest Di2 platform — shared with DURA-ACE R9200 — to deliver fully wireless communication between the lever and rear derailleur. Shifting is 58% faster at the rear and 45% faster at the front compared to the previous wired Di2 generation. The lever hood extends 4.6 mm further than the outgoing R8070 model, improving grip and reducing hand fatigue on long rides. Synchro Shift and Semi-Synchro modes can be configured via the Shimano E-Tube Project app over Bluetooth.

Hydraulic Braking

SERVO WAVE technology uses a variable leverage ratio across the lever stroke — lighter effort for rapid initial pad engagement, transitioning to firm, progressive stopping power deeper in the stroke. The system runs on Shimano mineral oil and features tool-free reach and free-stroke adjustment so you can fine-tune lever feel without removing the bar tape. Compatible with SM-BH90-JK-SSR brake hose (sold separately) and the BR-R8170 flat mount caliper for a complete Ultegra hydraulic system.

Compatibility & Fit

Right-hand lever (controls rear brake in Australian/standard road setup). Designed for use with Shimano Ultegra R8100 Di2 derailleurs and BR-R8170 hydraulic disc brake calipers. Fits standard drop bars with a clamp diameter of 23.8–24.2 mm. Requires Shimano mineral oil (not DOT fluid). Hose kit SM-BH90-JK-SSR, calipers, and Di2 junction units sold separately. Lever sold individually — left lever available separately (SHM-ISTR8170LE).