With the introduction of the Shimano GRX RX12 820-speed mechanical components, SHIMANO refines its series of gravel-specific components. Rooted in ease of use, reliability and adventure-readiness, the new 12-speed GRX range offers more drivetrain options along with unprecedented ergonomics. All to the advantage of a user experience that enables the cyclist to get the most out of every outing, wherever he is pedalling.
Source: press release
Focusing on the heart and soul of gravel cycling, the new mechanical Shimano GRX receives this 12-speed update that offers high-level performance and even more versatility of use. Precisely because gravel is all about personal expression and the freedom to choose how and where to pedal, the new range of Shimano GRX components offers three unique 12-speed mechanical drivetrain options to cover the entire spectrum of riders and terrain they ride on .
UNBEATABLE – SHIMANO GRX 1×12 – 10-45T
Cyclists who like to push their personal limits and challenge themselves in races will appreciate the gear ratios of the UNBEATABLE RX820 1×12 configuration which features a 10-45 tooth cassette combined with a 40 or 42 tooth chainring. Just like its 11-speed predecessor, the RX820 boasts smooth, reliable shifting but now features a wider gear range and extra cog, making it easier to find the optimal cadence in every situation.
This configuration uses the RD-RX822-GS medium cage rear derailleur designed for use in combination with the 10-45 tooth cassette, includes SHIMANO's integrated SHADOW RD+ chain stabilizer, which provides a quieter operation and safe handling of the chain on rough terrain.
FC-RX820-1 Crankset
- 1×12-speed gearing
- Crank arm lengths: 170mm, 172.5mm, 175mm
- Chainring options: 40T, 42T
- SHIMANO HOLLOWTECH II construction
- Weight: 655 grams (172.5mm with 40T chainring)
- SHIMANO SHADOW RD+ Chain Stabilization
- Max cassette range: 45T
- Interchangeable, replaceable GS/SGS derailleur cage
- Weight: 290 grams
UNSTOPPABLE – SHIMANO GRX 1×12 – 10-51T
For cyclists who prefer adventure cycling, articulated over one or more days riding challenging with a lot of height difference, the new UNSTOPPABLE RX820 1×12 option features a configuration that involves the combination of a 10-51 tooth SHIMANO cassette with a 40 or 42 tooth chainring. This setup offers optimal climbing gears for steeper roads or high mountain climbs.
The UNSTOPPABLE 1×12 speed configuration involves the use of an RD-RX822-GSG long cage rear derailleur equipped with an integrated SHADOW RD+ chain stabilizer, optimized for the use of the 10-51 tooth cassette. New for this generation of GRX components is the ability to change or replace the derailleur cage between the 1x12 drivetrain options. This means that if you need to replace your cage or your gearing needs change, you won't have to buy a completely new derailleur.
Additionally, Shimano brings its proven MICRO SPLINE mountain bike hub technology to the gravel arena on both 1x12 mechanical GRX setups. This lightweight aluminum freewheel design integrates seamlessly with the 10-tooth chainrings and features smaller, more spaced splines that limit gear damage over time.
RD-RX822-SGS Rear Derailleur
- 12 speed
- SHIMANO SHADOW RD+ Chain Stabilization
- Max cassette range: 51T
- Interchangeable, replaceable GS/SGS derailleur cage
- Weight: 288 grams (SGS)
FC-RX820-1 Crankset
- 1×12-speed gearing
- Crank arm lengths: 170mm, 172.5mm, 175mm
- Chainring options: 40T, 42T
- SHIMANO HOLLOWTECH II construction
- Weight: 655 grams (172.5 with 40T chainring)
CS-M8100-12 Cassettes
- Freehub type: MICRO SPLINE
- 10-51T
- Weight: 470 grams
UNDROPPABLE – SHIMANO GRX 2×12
For cyclists looking for the best of both worlds, competition and adventure, the new UNDROPPABLE 2×12 RX820 drivetrain features 48/31-tooth front chainrings paired with an 11-34 or 11-36-tooth cassette. This configuration offers an extremely wide range of gears to pedal with a comfortable cadence on all terrains, from flat to dirt roads and even the most difficult climbs.
This transmission option uses a mechanical derailleur at both the front and rear, the latter equipped with an integrated SHIMANO SHADOW RD+ chain stabilizer to guarantee maximum precision and safety when shifting on rough terrain. Choosing a 2X12 drivetrain offers tighter gear ratios, ideal for subtle cadence changes during competitions or spirited recreational weekend rides. The 2×12 drivetrain setup interfaces seamlessly with most existing 700c wheels on the market thanks to the use of the proven Shimano HG freehub body design.
- 2×12-speed gearing
- Crank arm lengths: 170mm, 172.5mm, 175mm
- Chain ring combination: 48-31T
- SHIMANO HOLLOWTECH II construction
- Weight: 721 grams (172.5 with 48/31T chainrings)
- 2×12-speed gearing
- Toggle link construction offers more cable routing options
- Wider tire clearance (chainline +2.5mm vs. conventional road FD)
- Precise and easy adjustment with integrated cable tension adjustment
- Weight: 95 grams
Updated ergonomics and brakes
The distinctive character of the GRX platform, which has its maximum expression in the ergonomics of the controls, continues with the new shift / brake levers that have been redesigned. Upgraded to 12-speed without any additional lever bulk, the RX820 Series shifters are designed for the flare-friendly comfort that has become a gravel cycling staple. By reducing the pressure points and increasing the contact surface, your hands will feel less tired giving you better control as you put your riding skills to the test.
New stock GRX shift/brake levers offer light and responsive 12-speed mechanical shifting. While the left lever of the UNDROPPABLE 2x12 GRX groupset offers the unrivaled smoothness of Shimano's front shifting, the new 1x12 groupsets carry over the functions of the left lever first introduced with the GRX 11-speed component series: a model with brake lever only and a specific option for the telescopic seat post which perfectly integrates braking and activation of the seat post itself.
ST-RX820-R/L – Hydraulic Disc Brake DUAL CONTROL Lever
- Gravel-specific brake lever and ergonomic bracket
- Optimized for use with flared handlebars
- Anti-slip coating on brake lever surface
- Light and responsive mechanical shifting
- Weight: 572.5 grams (2×12 ST pair)
- Weight: 511.2 grams (1×12 ST pair)
ST-RX820-LA – Hydraulic Disc Brake and Dropper Lever
- Left side brake and dropper post lever
- Gravel-specific brake lever and ergonomic bracket
- Optimized for use with flared handlebars
- Anti-slip coating on brake lever surface
- Weight: 263 grams
BL-RX820-L – Hydraulic Disc Brake Only
- Left side brake lever
- Gravel-specific brake lever and ergonomic bracket
- Optimized for use with flared handlebars
- Anti-slip coating on brake lever surface
- Weight: 222 grams
SHIMANO GRX RX610
For the more budget-conscious consumer, Shimano has updated the GRX 600-series drivetrain components for 1x12 and 2x12 setups that utilize the “trickle-down” technology of the GRX 800-class component line.
Key features include textured handguards and a non-slip brake lever coating that strengthens control on rough terrain. The new transmissions offer shifting options that specifically meet the needs of gravel drivers. The RX610 2×12 crankset is equipped with 46/30 tooth chainrings and is available with crank arms lengths of 165 mm, 170 mm, 172,5 mm and 175 mm. The RX610 1x12 crankset has the same four crank length options and is available in 38-tooth (new option) and 40-tooth high-strength steel chainrings to pair with a 10-45 or 10-51-tooth cassette.
- 1×12-speed gearing
- Crank arm lengths: 165mm, 170mm, 172.5mm, 175mm
- Chainring options: 38T and 40T
- Weight: 815 grams (with 40T chainring)
ST-RX610-R/L – Hydraulic Disc Brake DUAL CONTROL Lever
- Gravel-specific brake lever and ergonomic bracket
- Anti-slip coating on brake lever surface
- Light and responsive mechanical shifting
- Weight: 611 grams (2×12 pairs)
- Weight: 542 grams (1×12 pairs)
BL-RX610-L – Hydraulic Disc Brake Only
- Left side brake lever
- Gravel-specific brake lever and ergonomic bracket
- Anti-slip coating on brake lever surface
