Shimano GRX Di2 ST-RX815 Shift/Brake Lever Disc left black/anthracite

SHIMANO GRX - EXPLORE BEYOND
Designed for rides on rough roads, through gravel and mud, so you can get comfortable and stress-free wherever you want to go and achieve that unique feeling of performance. The first group of components developed by Shimano for gravel rides. Instead of telling gravel riders what they need, Shimano developers asked them what they wanted. Shimano has listened for two years and spent countless hours talking to Gravel enthusiasts from around the world. They drove on dust and gravel roads and narrow tracks, crossed streams and mountain passes to imagine what a Shimano Gravel group could look like. The result of all these trips and also new friendships? First the Shimano Gravel Alliance and now the Shimano GRX - the world's first series with components designed specifically for gravel.

The goal is not to dominate the Gravel scene or change its direction. Shimano did not want to reinvent the wheel. The engineers at Shimano love Graveln as he is. Shimano simply wanted to give you and your friends the opportunity to ride the bike the way you want with a new group of components. And the GRX does just that.

And last but not least, the developers envisioned a Shimano GRX group that delivers top performance in gravel racing while offering options that make it affordable for cost-conscious drivers. By setting these design goals, Shimano has developed components that are also suitable for cyclocross, bike adventures and almost every similar type of bicycle diszplin. Simply put, the Shimano GRX is the world's best way to move freely and discover new territory on the Gravel bike.

E-TUBE
Thanks to the "Plug & Play" connections of the E-TUBE platform and the D-FLY wireless connections, it is easier than ever to check the status of the system and apply customized settings for DI2 and SHIMANO STEPS components with a PC, tablet or smartphone.
Functions such as SHIMANO SYNCHRONIZED SHIFT can be adjusted wirelessly via Bluetooth while driving. At each start, an automatic check for firmware updates is performed to ensure that the current version is running on all components. The PC, Smartphone and Tablet applications facilitate rapid troubleshooting and simplify the repair process. E-Tube provides a nice visual implementation of the SHIMANO STEPS real-time driving data on your smartphone.

SEIS - SHIMANO ELECTRONIC INTELLIGENT SYSTEM
A technologically innovative, computerized switching system based on the DI2 concept called SEIS (SHIMANO ELECTRONIC INTELLIGENT SYSTEM).
The innovative switching technology of the SEIS is still based on the SHIMANO INDEX SYSTEM (SIS), whose outstanding switching capacity has proven itself over many years. The main difference between the systems is that the switching process is no longer mechanical, but electronic.
This electronic switching system has been extensively tested in recent years by several professional cyclists under all conceivable conditions, e.g. rain, mud, extreme cold, on cobblestones and even a combination of these factors. The switching process is carried out by simply pressing a button. No effort is required to shift gears, which has significant advantages, as the driver always has a firm grip on the handlebars and can concentrate on driving without being distracted by the gearshift. The shifting system allows precise and effortless shifting in all situations, even with cold hands or when the driver has fully exerted himself. The shifting capacity can also no longer be affected by dirty or stretched trains as the shift signal is transmitted electronically. The control buttons work in a similar way to mechanical DUAL CONTROL levers, making it easy to get used to the SEIS.

DUAL CONTROL LEVER
DCL stands for DUAL CONTROL LEVER. It has braking and switching functions and is easy to operate. The improved ergonomics are probably even more important for the high standard than additional ratios. The technology of the new shift levers provides the stability of MTB technology and works so precisely and smoothly that it is possible to shift front and rear gears with just one finger. This is really a highlight of the SHIMANO TOTAL INTEGRATION. To understand this, you simply have to experience it for yourself.
The dual-control shift/brake levers from DURA-ACE, ULTEGRA and 105 have been optimised and now feature, for example, a weight-reduced joint on the inside of the shift mechanism and integration of the cable for easier steering. The extremely compact and high-precision manufactured individual parts result in an extremely high level of precision.

REACH ADJUST
The brake lever is equipped with a handle width adjustment. This allows the handle to adapt to the size of the driver's hand, driving style or personal preferences.

SHIMANO SHADOW RD+
Shadow RD+ means for Shimano a low-noise drive with an additional rear derailleur stabilizer, which reduces the impact of the chain to prevent the chain from jumping off.