The Shimano Dura-Ace ST-R9170-L is the left-hand STI lever from Shimano's flagship road groupset, combining electronic Di2 shifting with hydraulic disc braking in a single precision control unit. Designed for road racing at the highest level, it delivers effortless, cable-free gear changes and powerful, consistent stopping power in all conditions.

Highlights

• Dura-Ace Di2 electronic shifting — no cables to stretch, corrode, or adjust
• Integrated hydraulic disc brake with optimised lever stroke, contact point, and stiffness for racing
• Carbon composite plastic hood for lightweight, comfortable grip
• Reach Adjust technology suits a wide range of hand sizes
• Customisable hidden button on top of the hood via E-TUBE Project app
• Two SD50 e-Tube ports for connecting derailleurs, satellites, or accessories
• More defined click feeling and ergonomic shift lever position for intuitive, quicker operation
• Openable hood cover for straightforward servicing

Electronic Di2 Shifting

The ST-R9170 replaces mechanical cables with electrical signals, eliminating shifting degradation caused by cable stretch, friction, and contamination. The E-TUBE Project ecosystem lets you customise button functions, set multi-shift sequences, and monitor system status — all from a smartphone or PC. The hidden top-of-hood button adds a third programmable switch to the lever.

Hydraulic Disc Braking

Shimano's hydraulic system delivers a progressive, powerful brake feel with an adjustable free stroke to fine-tune the lever's engagement point. The lever is engineered as a flat-mount disc brake system, pairing directly with Dura-Ace BR-R9170 flat-mount calipers. Compatible rotors are 140 mm or 160 mm; 180 mm and 203 mm rotors are not supported.

Compatibility & Fit

This is the left lever only, controlling the front brake and 2-speed front derailleur (2x11-speed). Designed for Shimano Dura-Ace R9150/R9170 Di2 groupsets. Pairs with FD-R9150 front derailleur and BR-R9170 flat-mount caliper. Requires Shimano mineral oil. Compatible with SW-R9150 satellite shifters. Not compatible with SW-R610 sprint shifters. Handlebar clamp bore: 23.8–24.2 mm.