Shimano GRX ST-RX815 Di2 Shift Hydraulic STI Lever

Shimano GRX, with its gravel specific ergonomics, optimized gearing options, rugged reliability, and quiet and stable drivetrain, sets itself apart from the rest of the component world.

The Shimano GRX Di2 Dual Control Lever delivers light and responsive shifting for mixed-terrain riding. The ergonomic shifter design improves comfort and the textured, anti-slip brake lever increases control on bumpy terrain. The Di2 version offers the digital precision of Shimano electronic shifting and synchronized shifting.

Technology

Dual Control Lever

DCL stands for Dual Control Lever. It has brake and shifting functions in the system and enables easy operation.

Ergonomic innovation is probably more critical to the higher standard performance than the added gearing. The shift internals borrow the robustness from our MTB technology and are so smooth and effortless that one finger shifts front and rear are possible. Indeed, shifting is the ultimate act of Shimano Total Integration, and simply has to be experienced to be understood.

The Dura-Ace / Ultegra / 105 Dual Control Lever have an optimized structure with features that include the lighter weight pivot section in the near side of the shifting unit and the integral shifting cable for lighter steering. Its many component parts are made so compact and precise to achieve unprecedented high-speed performance.

SEIS

A technological innovation of the computerized shifting system based on the Di2 concept with which is called, the SEIS (Shimano Electronic Intelligent System).

The SEIS innovative shift technology is still based on the Shimano Index System (SIS) that has proved its superior gear changing characteristics over the years. The big difference is that in this case, the shifting action is provided for by electronics instead of mechanics.

This electronic shifting system has been extensively tested over past two years by several professional riders in all conditions possible, such as rain, mud, low temperatures, cobble stone roads and combinations of all of these at the same time.

Shifting is executed by simply pressing the button. No power is needed to shift, which gives important advantages since it is easier now to always keep a tight grip on the handlebar and to keep your concentration on riding instead on shifting.

The shift system allows accurate and effortless shifting in difficult circumstances for example when you have cold hands or when you are completely exhausted. Furthermore, the shifting performance will never be affected by contaminated or stretched cables since the shifting signal is transferred electronically. The operating buttons work similarly to mechanical Dual Control Lever so you don’t need to re-program your mind for the SEIS.

E-Tube

E-Tube is Shimano's “service” that uses websites or apps to maximize the enjoyment of riding a bicycle by connecting the riders, the bicycles and Shimano.

Shimano’s genuine application E-Tube Project for Mobile allows you to customize your bike, update firmware, and maintain it by connecting it wirelessly to your bike. You can also get the more detailed bike maintenance by connecting to your bike by wire with E-Tube Project for Windows V4 application.

• Easily update to the latest firmware with the user-friendly interface
• Set two e-bike assist profiles to your preference, and customize the assist characteristics according to the riding situation
• Design your favorite Di2 gearshift in Synchronized Shift
• Easily adjust both front and rear derailleurs via application

Reach Adjust

Brake lever is equipped with a reach adjust mechanism. The distance from handlebar grip to lever can be adjusted to suit any hand size, type of riding and individual rider preferences.

Features

• GRX hydraulic disc brake Di2 STI's give you control, modulation and power with minimal effort in all riding conditions
• Higher brake lever axis and curved brake lever,improves grip and confidence on choppy surfaces and descents
• Raised hood head prevents hand misalignment and slippage
• Recessed finger notch prevents upward slipping
• Anti-slip texture and brake lever coating gives higher braking efficiency and reduces fatigue on long rides
• 11-speed E-tube Di2 compatible
• Left hand 2-speed lever