Shimano launches 12-speed GRX groupset for Gravel | 3bikes.fr, your Cycling, Gravel & Triathlon magazine

With the introduction of the GRX RX820 12-speed mechanical components, Shimano continues its innovations as a pioneer of gravel-specific components. The new 12-speed GRX range offers more gearing options in 1x or 2x chainring configurations, as well as new ergonomics, so riders can make the most of every adventure, wherever it may be.

Source: Press Release

Focusing on the heart and soul of Gravel, the Shimano GRX mechanical range receives this twelfth speed, offering high-level performance at an accessible price. Since Gravel is about personal expression and the freedom to choose how and where to ride, the new Shimano GRX mechanical component range offers three 12-speed drivetrain options to cover the entire spectrum of rider types and terrains.

The Shimano GRX 1×12 with 10-45 cassette

Riders who like to beat personal records or compete for the end of a race will appreciate the gear ratios of the 10-45 cassette paired with a 40 or 42-tooth chainring from the RX820 1×12 speed range. Like its 11-speed predecessor, the RX820 version offers smooth and reliable shifting. It now has a wider gear range and an additional cog, making it easier to find the optimal cadence to maintain your position at the front of the pack.

This configuration uses the RD-RX822-GS (medium cage) rear derailleur designed for use with the 10-45 cassette and includes the integrated SHADOW RD+ chain stabilizer, offering quieter and more stable shifting on rough terrain.

FC-RX820-1 Crankset

1×12 speed
Crank arm length: 170mm, 172.5mm, 175mm
Available chainrings: 40, 42 teeth
SHIMANO HOLLOWTECH II construction
Weight: 655 g (172.5mm with 40-tooth chainring)

RD-RX822-GS Rear Derailleur

SHIMANO SHADOW RD+
Maximum capacity: 45 teeth
Interchangeable derailleur cage, replaceable with GS/SGS cage
Weight: 290 g

CS-M8100-12 Cassette

For MICRO SPLINE freehub body type
10-45 teeth
Weight: 461 g

The Shimano GRX 1×12 with 10-51 cassette

For day-long or multi-day adventures, the new RX820 1×12 option includes a 40 or 42-tooth chainring with the large capacity of the 10-51 cassette. This configuration offers optimal ratios for the steepest roads or high mountain climbs.

The 1×12 speed configuration includes the RD-RX822-GSG long cage rear derailleur with integrated SHADOW RD+ chain stabilizer, optimized for use with the 10-51 cassette.

New to this generation of GRX is the ability to change or replace the derailleur cage between the 1×12 options. This means that if you need to replace your cage or switch to a larger cassette, you don’t have to buy a whole new derailleur.

In addition, Shimano brings its proven MTB freehub body technology, MICRO SPLINE, to Gravel, with both GRX 1×12 mechanical configurations. This lightweight aluminum design is specifically intended for the 10-tooth cog.

RD-RX822-SGS Rear Derailleur

12 speed
SHIMANO SHADOW RD+
Maximum capacity: 51 teeth
Interchangeable derailleur cage, replaceable with GS/SGS cage
Weight: 288 g (SGS)

FC-RX820-1 Crankset

1×12 speed
Crank arm length: 170 mm, 172.5 mm, 175 mm
Chainring options: 40, 42 teeth
SHIMANO HOLLOWTECH II construction
Weight: 655 g (172.5mm with 40-tooth chainring)

CS-M8100-12 Cassette

For MICRO SPLINE freehub body type
10-51 teeth
Weight: 470 g

The Shimano GRX 2×12

For cyclists looking for the best of both worlds, the new 2×12 RX820 drivetrain uses gravel-optimized 48-31 tooth chainrings, paired with an 11-34 or 11-36 cassette. This configuration offers an ultra-wide gear range to keep the legs spinning at a comfortable cadence on the flats, devour endless miles of dirt roads, or tackle a big climb.

This option offers precise mechanical front and rear shifting, and includes an integrated SHADOW RD+ chain stabilizer for ultimate chain security on rough terrain. It maintains closer gear steps, ideal for subtle cadence changes during races or lively weekend group rides. The 2×12 configuration harmonizes perfectly with most existing 700c wheels thanks to its HG freehub body compatibility.

FC-RX820-2 Crankset

2×12 speed
Crank arm length: 170 mm, 172.5 mm, 175 mm
Chainring teeth: 48-31
SHIMANO HOLLOWTECH II construction
Weight: 721 g (172.5mm with 48/31 chainring)

RD-RX820 Rear Derailleur

12 speed
SHIMANO SHADOW RD+
Maximum capacity: 36 teeth
Weight: 270 g

FD-RX820 Front Derailleur

2×12 speed
Toggle-plate construction offering more cable routing options
More clearance (+2.5mm chain line compared to a conventional road derailleur)
Precise and simplified adjustment with integrated cable tension screw
Weight: 95 g

CS-R8101-12 and CS-HG710-12 Cassettes

CS-R8101-12: 11-34 teeth
Weight: 345 g
For HG and HG+ freehub body type
CS-HG710-12: 11-36 teeth
Weight: 391 g
For HG and HG+ freehub body type

Revised Ergonomics and Brakes

The ergonomic character of the GRX range continues with its redesigned shift/brake levers. The RX820 series shifters are designed to provide all-day comfort when using flared handlebars – a gravel riding essential. By reducing pressure points and increasing contact area, your hands will feel less fatigued and you’ll have better control when pushing your limits.

The new GRX controls offer smooth and responsive 12-speed mechanical shifting. While the left lever of the GRX 2×12 version offers unparalleled chainring shifting, the new 1×12 groupsets offer left lever functions, first introduced with the original GRX range. These include a brake-only lever model and a specific shifter reference that seamlessly integrates braking and dropper post actuation.

DUAL CONTROL ST-RX820-R/L Hydraulic Shifters

Ergonomics specifically designed for gravel
Optimized for use with flared handlebars
Anti-slip coating on the hoods
Smooth and fast shifting
Weight: 572.5 g (2×12 ST pair)
Weight: 511.2 g (1×12 ST pair)

ST-RX820-LA Hydraulic Shifters – dropper post compatible

Left brake lever and dropper post control
Ergonomics specifically designed for gravel
Optimized for use with flared handlebars
Anti-slip coating on the hoods
Weight: 263 g
Left brake lever
Ergonomics specifically designed for gravel
Optimized for use with flared handlebars
Anti-slip coating on the hoods
Weight: 222 g

The Shimano GRX RX610

For budget-conscious riders and to allow for a wider price range on complete Gravel bikes, Shimano has also updated its 600 series cranksets and shifters for 1×12 and 2×12 configurations. These use technology inherited from the original GRX 800 component range.

Key ergonomic features include textured hood covers and an anti-slip brake lever coating that enhances control on rough terrain. The new cranksets offer chainring options that specifically meet the demands of gravel riding. The RX610 2×12 crankset features 46/30 chainrings and is available in various crank arm lengths: 165mm, 170mm, 172.5mm, and 175mm. The RX610 1×12 crankset has the same 4 crank arm length options and is available with 38-tooth (new option) and 40-tooth steel chainrings to pair with a 10-45 or 10-51 cassette.

FC-RX610-1 Crankset