In addition to the new 105 12-Speed groupset, SHIMANO have launched GRX Mechanical 12-Speed components. As our Events Calendar shows, gravel is here to stay. Check out the full press release here:

With the introduction of Shimano GRX RX820 12-speed mechanical components, Shimano continues its legacy of innovation as the originator of gravel-specific componentry. Rooted in simplicity, reliability, and adventure, the new 12-speed GRX lineup delivers more gearing options along with unrivaled ergonomics, so riders get the most out of each unpaved adventure, wherever that might be.
With a focus on the heart and soul of gravel cycling, Shimano mechanical GRX receives this 12-speed upgrade delivering top-tier performance without an over-the-top price. Since gravel is all about personal expression and freedom to choose how and where to ride, Shimano GRX includes three unique 12-speed mechanical drivetrain personalities to cover the full spectrum of riders and rides.



UNBEATABLE – SHIMANO GRX 1×12 with 10-45T
Riders who love pushing for personal bests or duking it out at the sharp end of a race, will appreciate the gear steps of the RX820 1×12 UNBEATABLE setup with a 10-45 cassette paired with a 40- or 42-tooth chainring. Like its 11-speed predecessor, RX820 delivers smooth, reliable shifting and now features a wider gear range and extra cog, making it easier to find the optimal cadence for maintaining your position in the pack.

This setup employs the RD-RX822-GS medium cage rear derailleur designed for use with the 10-45T cassette and includes Shimano’s integrated SHADOW RD+ chain stabilizer — providing quieter shifting and secure chain management in 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
- 655 grams (172.5mm with 40T chainring)
RD-RX822-GS Rear Derailleur
- SHIMANO SHADOW RD+ Chain Stabilization
- Max cassette range: 45T
- Interchangeable, replaceable GS/SGS derailleur cage – 290 grams
CS-M8100-12 Cassette
- Freehub type: MICRO SPLINE – 10-45T range
- 461 grams
UNSTOPPABLE – SHIMANO GRX 1×12 with 10-51T
For all-day—or multi-day—adventures heavy on climbing, the new RX820 1×12 UNSTOPPABLE option features Shimano’s wide-range, 10-51T cassette along with a 40- or 42-tooth chainring. This setup delivers optimal climbing gears for the steepest fire roads or high mountain ascents.

The UNSTOPPABLE 1×12-speed setup includes the RD-RX822-GSG long-cage rear derailleur with integrated SHADOW RD+ chain stabilizer that is optimized for use with the 10-51T cassette. New for this generation of GRX is the ability to change or replace the derailleur cage between 1×12 options. This means if you need to replace your cage or your gearing needs to change, you don’t have to buy a whole new derailleur. Additionally, Shimano brings its proven MICRO SPLINE mountain bike hub technology to gravel with both 1×12 mechanical GRX setups. This lightweight aluminum freehub design seamlessly integrates with 10- tooth top gears and features smaller, more widely spaced splines that limit cog 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 – 288 grams
FC-RX820-1 Crankset
– 1×12-speed gearing
– Crank arm lengths: 170 mm, 172.5 mm, 175 mm
– Chainring options: 40T, 42T
– SHIMANO HOLLOWTECH II construction – 655 grams (172.5 with 40T chainring)
CS-M8100-12 Cassette
– Freehub type: MICRO SPLINE – 10-51T
– 470 grams
UNDROPPABLE – SHIMANO GRX 2×12
This option delivers precise mechanical front and rear shifting and features integrated SHADOW RD+ chain stabilizer for ultimate drivetrain security over bumpy terrain. It maintains tighter rear cassette gear steps, ideal for subtle cadence changes during competitive racing and spirited weekend group rides. The 2×12 setup seamlessly interfaces with most existing 700c wheels thanks to its use of the tried- and-true HG freehub body design.

FC-RX820-2 Crankset
- 2×12-speed gearing
- Crank arm lengths: 170 mm, 172.5 mm, 175 mm – Chainring combination: 48-31T
- SHIMANO HOLLOWTECH II construction
- 721 grams (172.5 with 48/31T chainrings)
RD-RX820 Rear Derailleur
- 12-speed
- SHIMANO SHADOW RD+ Chain Stabilization – Max cassette range: 36T
- 270 grams
FD-RX820 Front Derailleur - 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
- 95 grams
CS-R8100-12 and CS-HG710-12 Cassette
- CS-R8100-12 range: 11-34T
-345 grams - Freehub type: HG and HG L2 – CS-HG710-12 range: 11-36T
- 391 grams
- Freehub type: HG and HG L2
Updated Ergonomics and Brakes
GRX’s ergonomic distinctiveness continues with its redesigned shift/brake levers. Adding 12-speed shifting without any additional lever bulk, the RX820 series shifters are designed for all-day comfort when using flared drop bars–a gravel cycling staple. By reducing pressure points and increasing surface area, your hands will feel less fatigued, and you’ll be better in control as you test your limits.
The new GRX shift/brake levers offer light and responsive mechanical 12-speed shifting. While the left lever of the UNDROPPABLE 2×12 GRX group delivers Shimano’s unrivalled smooth front shifting, the new 1×12 groups carry over functions for the left lever first introduced with the original GRX: a brake lever- only model and a dropper-specific option that seamlessly integrates braking and dropper post actuation.

ST-RX820-R/L – Hydraulic Disc Brake DUAL CONTROL Lever
- Gravel-specific brake lever and bracket ergonomics – Optimized for use with flared handlebar
- Anti-slip coating on brake lever surface
- Light and responsive mechanical shifting
- 572.5 grams (2×12 ST pair) – 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 bracket ergonomics
- Optimized for use with flared handlebar
- Anti-slip coating on brake lever surface
- 263 grams
BL-RX820-L – Hydraulic Disc Brake Only
- Left side brake lever
- Gravel-specific brake lever and bracket ergonomics – Optimized for use with flared handlebar
- Anti-slip coating on brake lever surface
- 222 grams

SHIMANO GRX RX610
For the more budget conscious consumer and to allow a wider price range on complete gravel bikes, Shimano has also updated its 600-series cranks and shift levers for 1×12 and 2×12 setups that utilize trickle-down technology from the original 800 series GRX component line.
Top features include textured hoods and anti-slip brake lever coating that bolsters control on rugged terrain. The new cranksets offer gearing options that specifically cater to the demands of gravel riding. The RX610 2×12 crank features 46/30 chainrings and is available in 165 mm, 170 mm, 172.5 mm, and 175 mm crank arm lengths. The RX610 1×12 crank has the same four crank length options and is available with highly durable steel 38T (a new option) and 40T chainrings to pair with a 10-45T or 10-51T cassette.
SHIMANO RX880 Carbon Gravel Wheels
Along with GRX mechanical components, Shimano is also introducing an updated carbon gravel wheel that’s purpose-built to handle the rough-and-tumble rigors of dirt road riding. The new RX880 wheelset is a full 64 grams lighter per pair than its predecessor and features the same shallow 32mm rim height for faster acceleration and quicker climbing. The RX880 wheels are tubeless-ready and employ a progressive 25 mm inner rim width that’s suitable for tyres from 32 mm to 50 mm wide.

User-friendly compatibility is further enhanced via a revamped DIRECT ENGAGEMENT hub design, borrowed from DURA-ACE wheels, that easily converts between MICRO SPLINE and HG L2 12-speed freehub bodies. It features quick and efficient engagement for rapid acceleration no matter what the riding surface. The RX880 hubs and rims are laced with 24 J-bend spokes front and rear that maximize strength and reliability no matter how adventurous your next ride gets.
WH-RX880-TL Carbon Tubeless Wheels
- DIRECT ENGAGEMENT freehub – Rim height: 32mm
- Internal width: 25mm
- Full carbon rim
- Recommended tire size: 32-50mm
- Replaceable freehub body – switch between
MICRO SPLINE and HG L2
Note: Not compatible with 11-speed HG cassettes - 1394 grams (MICRO SPLINE) – 1397 grams (HG L2)

Stock is expected in December, with pricing TBC. For more product info check out road.shimano.com and get in touch with Coolheat for local queries.
I’ve always wanted to convert my hardtail into a gravel bike now I can hopefully just get the GRX shifters paired with my SLX 12 speed setup and some new handlebars.