Bring the precision of Dura-Ace Di2 shifting and the stopping power of hydraulic disc brakes to your time trial or triathlon build. This matched set pairs the ST-R9180 left lever — which controls rear braking and Di2 rear shifting — with the BR-R9270 rear disc brake caliper, giving you seamless electronic control and fade-resistant hydraulic braking in a single, integrated package.

Highlights

• Dura-Ace Di2 electronic shifting with Synchro-Shift mode for single-button control of both derailleurs
• Hydraulic disc braking with mineral oil fluid for consistent, low-maintenance performance
• BR-R9270 Mono-Body caliper cold-forged from a single aluminium block — exceptionally light and rigid
• 10% larger brake pad clearance compared to previous generation, reducing rotor noise
• Adjustable reach on the lever body to suit a wide range of hand sizes
• Ice-Tech resin brake pads (L03A) with cooling fins for superior heat dissipation
• One-Way Bleeding system with Easy Hose Joint for straightforward maintenance and hose replacement
• Flat mount caliper standard — clean integration with modern road and TT framesets

Lever & Shifting

The ST-R9180 is purpose-built for TT and triathlon handlebars with an inner diameter of 19–22.5 mm (aluminium or aluminium-insert bars). Its carbon fibre reinforced polymer (CFRP) construction keeps weight low while the ergonomic lever shape allows braking from multiple hand positions — ideal for aero bars. Di2 Synchro-Shift intelligently manages both front and rear derailleurs with a single button press, letting you focus on your effort rather than your gearing. The lever connects to the Di2 system via a single EW-SD50 port.

Caliper & Braking

The BR-R9270 rear caliper uses a 2-piston hydraulic design with mineral oil for consistent bite and modulation across long descents and variable conditions. The Mono-Body single-piece cold-forged aluminium construction improves rigidity without adding weight — the rear caliper weighs approximately 110 g. Flat mount compatibility and support for 140 mm and 160 mm rotors (rotor and adapters sold separately) makes it broadly compatible with current TT and road disc frames. Maintenance is simplified by the One-Way Bleeding system and J-Kit hose joint.

Compatibility & Fit

This is the left lever / rear brake set, appropriate for Australian riding convention (left lever controls rear brake). Compatible with Shimano 11-speed Dura-Ace Di2 drivetrains; use the EW-AD305 adapter for compatibility with 12-speed R9200 Di2 components. Handlebar inner diameter must be 19–22.5 mm. Flat mount frame required. Rotors sold separately; compatible with 140 mm and 160 mm flat mount rotors including the RT-MT900 series. SM-BH90 brake hose (1700 mm) included.