Shimano has entered the wireless drop-bar era with the launch of its all-new GRX 1×12-speed Di2 groupset, designed specifically for gravel riding. The GRX RX827 series employs a fully wireless drive system, building on the wireless shifters from Shimano’s 2×12 road and gravel lines and incorporating the same wireless technology first seen in the XTR M9200 rear derailleur. Engineered for performance, durability, and versatility, the RX827 completes the GRX lineup—which now includes both mechanical and electronic options in 1x and 2x configurations—allowing riders to build their ideal gravel drivetrain.
Designed for Freedom and Compatibility
The GRX RX827 system is rider-focused and frame-agnostic. It fits a wide range of gravel bikes without special compatibility requirements, letting you upgrade your current bike with Shimano’s latest wireless technology for more adventurous rides.
Centered around the RD-RX827 wireless rear derailleur, the GRX 1×12 system delivers precise shifting and reliable chain control across mixed terrain. Built for everything from racing and backroad exploring to all-day adventures, it puts you in full command.
Key Features of GRX 1×12 Di2
- Fully Wireless Di2 Platform: Delivers fast, precise shifting with excellent reliability. Compatible with all Shimano 12-speed wireless shifters, including GRX, DURA-ACE, ULTEGRA, and 105 Di2 for drop bars, as well as XTR and XT Di2 trigger shifters for flat bars.
- Robust Gravel Drivetrain: The RX827 derailleur borrows design elements from Shimano’s mountain Di2 series, featuring a narrow profile, impact guard, built-in battery protection, and automatic impact recovery.
- Optimized Ergonomics: Offers a secure grip, clean cockpit layout, and customization options for improved control and comfort.
- Expanded Compatibility: A wide selection of GRX components lets riders fine-tune their setup for terrain, riding style, and preference.
The GRX Wireless Drivetrain in Detail
The new GRX 1×12 system pairs the RD-RX827 wireless rear derailleur with the existing RX825 Di2 shifters, RX820 crankset, brakes, and a 10-51T XT cassette. The result is a clean, tough 1×12 setup with Shimano’s signature Di2 shifting performance.
Riders can choose between 40T or 42T chainrings and match them with Shimano’s 10-51T Micro Spline cassette range. The RX827 also offers an electronic shifting solution for flat-bar mountain or adventure bikes using MTB cranks. Whether climbing steep grades or cruising flat sections, GRX adapts to a variety of styles and terrains.
SHIMANO SHADOW ES Rear Derailleur Technology
The GRX RX827 derailleur features the new SHIMANO SHADOW ES design, offered only in a long-cage SGS version focused on durability and function. Its low-profile wedge shape and integrated chain stabilizer reduce exposed areas, while rounded edges help it deflect impacts from rocks and debris.
When impacts do occur, the derailleur absorbs the force, and Shimano’s automatic impact recovery returns it to its original position—often without the rider even noticing.
A wide-link construction, reinforced guide plate, impact guard, and solid pulleys further boost durability in muddy and rough conditions.
Derailleur Tech Highlights
- Low-Profile Design: SHIMANO SHADOW ES wedge shape reduces frontal area and snag-prone edges.
- Automatic Impact Recovery: The derailleur self-corrects after a strike to maintain shifting stability.
- Rugged Construction: Wide linkage and solid pulleys resist debris and improve longevity.
- New Chain Stabilization: A dual-spring system increases chain tension for better retention and wrap.
- Protected Battery: A sealed, removable battery is tucked inside the derailleur body for security and easy charging.
RD-RX827 Wireless Rear Derailleur Specs
SHIMANO SHADOW ES technology
Precise wireless electronic shifting
Impact guard and robust construction
Solid pulley wheel system
Removable, rechargeable internal battery
Battery life: approx. 700–1,000 km per charge
Long cage (SGS), compatible with 10-51T 12-speed cassettes
Weight: 449 g
New Brake-Only Lever for Streamlined Setups
For riders who prefer a simplified 1x cockpit, Shimano introduces the BL-RX825-L hydraulic disc brake lever. This brake-only lever retains the ergonomic benefits of the RX825 dual-control lever—including the raised hood with non-slip texture and grippy brake lever—but omits the shift buttons for a cleaner, lighter setup.
BL-RX825-L Hydraulic Brake Lever
Brake-only option for 1×12 systems
Gravel-optimized ergonomics
Designed for flared gravel bars
Non-slip coating on brake lever
Saves 19.5 g vs. ST-RX825-L (188 g vs. 207.5 g)
Advanced Di2 Customization
Whether using the new BL-RX825-L brake lever or a pair of GRX ST-RX825 dual-control levers, the GRX 1×12 system supports a wide range of shifting configurations via customizable Di2 buttons and auxiliary shift switches.
The ST-RX825 shifters include three Di2 buttons—two on the lever and one inside the hood—and support additional auxiliary buttons mounted on the bar tops, drops, or aerobars. Each button can be assigned functions such as shifting, controlling compatible lights or computers, or activating shift micro-adjustment for precise tuning on the fly.
SHIMANO RX180 Tubeless-Ready Alloy Wheelset
Alongside the new groupset, Shimano introduces the RX180, an affordable and reliable alloy gravel wheelset. Designed for strength and versatility, it features a tubeless-ready design with a 25 mm internal width, compatible with 32–50 mm tires for a stable, adaptable gravel setup.
The RX180 uses a new interchangeable freehub system that easily swaps between Micro Spline and HG Lite, supporting one-piece or two-piece drivetrains and a range of 10-, 11-, and 12-speed cassettes.
WH-RX180-TL-700C Wheelset Specs
Interchangeable freehub: Micro Spline and HG Lite
25 mm internal width
Hooked tubeless rim
Quality alloy construction at an accessible price
Weight: 2105 g (with HG Lite), 2113 g (with Micro Spline)
With the launch of the GRX 1×12 Di2 groupset, Shimano delivers a wireless, robust, and highly adaptable gravel solution ready for any path you choose.
