Shimano GRX RX820 brings an extra cog, increased gear range and other features to the gravel party

While Shimano’s GRX RX820 is 12-speed, with options for a wider gear range, it’s still mechanical. That’s not to say that Shimano aren’t planning to make a Di2 version: just not yet. However that’s not an issue for me, I’ve always found Shimano’s mechanical shifting to be spot on. Reading some of the PR material, Shimano do say that GRX RX820 is “rooted in simplicity, reliability, and adventure.” In fact it makes sense for those riders that are looking to take on long-haul trips. They may be travelling off-grid, where battery charging isn’t an option, making a mechanical option a bonus.

In a move unusual for Shimano, GRX RX820 has been split into three “personalities”; Unbeatable, Unstoppable and Undroppable. Usually Shimano would use a numeric system to differentiate between sub-families, but gravel is special! Apparently this is because gravel is “all about personal expression and freedom“.

Unbeatable – GRX 1×12 with 10-45

Unbeatable is aimed at the those wanting to race. They get a 10-45 cassette paired with either a 40 or 42 tooth chainring. Shimano says that like its predecessor you’ll get the same smooth and reliable shifting, but with a wider gear-range and an extra cog. This is intended to make it easier to “find the optimal cadence for maintaining your position in the pack.“

The Unbeatable range uses the RD-RX822-GS medium cage rear derailleur. This is designed for use with a 10-45 cassette. It also has Shimano’s integrated SHADOW RD+ chain stabiliser, which is designed to provide quieter shifting and lessen chain-slap.

Unbeatable specs

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 – GRX 1×12 with 10-51

Unstoppable is aimed at the adventurers out there. Those that are heading out on long, hilly rides over one or more days. To help you carry your loaded bike over long hills, Unstoppable pairs a 40t chainring with a 10-51 cassette: plenty of gears there.

Unstoppable uses the RD-RX822-GSG long-cage rear derailleur, which also uses SHADOW RD+ stabilisation. The long and medium RD-RX822 cages are interchangeable, handy if you’re swapping gears. That’s also good news if you damage and need to replace your cage.

Unbeatable and Unstoppable both use Shimano’s MICRO SPLINE mountain bike hub technology. This allows the use of a 10t cog and has smaller, more widely spaced splines. The latter apparently limits cog damage over time, which should mean longer lasting components.

Unstoppable specs

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 2×12

Undroppable is aimed at riders that want to do it all. The RX820 Undroppable drivetrain uses 48/31t chainrings paired with an 11-34T or 11-36T cassette. According to Shimano this will give you an “ultrawide gear range for spinning a comfortable cadence when cruising the flats, smashing endless dirt-road rollers, or tackling a massive backcountry climb.”

The Undroppable RX820 derailleur also has SHADOW RD+ chain stabilisation. The tighter rear cassette reduces the jumps between gears, allowing you to fine tune your cadence. The 2×12 option uses the tried and tested HG freehub design.

Undroppable specs

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

FD-RX820 Front Derailleur
– 2×12-speed gearing
– Toggle link construction offers more cable routing options
– Wider tire clearance
o 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
o 345 grams
o Freehub type: HG and HG L2 
– CS-HG710-12 range: 11-36T
o 391 grams
o Freehub type: HG and HG L2

Updated ergonomics

The RX820 series shifters have had a re-design, optimising them for use on flared bars. The re-design seeks to reduce pressure points and increase the surface for your hands. I’ve always found Shimano’s shifting to be faultless and expect the same of the new 12-speed shifters. Apparently they’ve managed to add the extra cog without adding any bulk to the shifter body.

Shimano have also brought in some material knowledge from the world of fishing. The lever hoods are now made from a material that was developed for Shimano’s fishing rods. This should give you extra grip on wet rides.

While the Undroppable’s left-hand lever deals with front shifting, with 1×12 you have options. You can get a brake lever only option, keeping it simple. Alternatively there’s a dropper-specific option, if that’s what you need.

RX820 shifter specs

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 coa􀆟ng 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

Shimano has also updated the cranks and shifters of its 600 series. The 600 series is seen as being aimed at the “budget conscious consumer”, however it will use some of the features from the 800 series. These include textured hoods and anti-slip brake lever coating.

GRX RX610 specs

FC-RX610-1 Crankset
– 1×12-speed gearing
– Crank arm lengths: 165 mm, 170 mm, 172.5 mm, 175 mm
– Chainring options: 38T and 40T
– 815 grams (with 40T chainring)

FC-RX610-2 Crankset
– 2×12-speed gearing
– Crank arm lengths: 165 mm, 170 mm, 172.5 mm, 175mm
– Chainring combination: 46-30T
– 815 grams (with 46/30T chainrings)

ST-RX610-R/L – Hydraulic Disc Brake DUAL CONTROL Lever
– Gravel-specific brake lever and bracket ergonomics
– Anti-slip coating on brake lever surface
– Light and responsive mechanical shifting
– 611 grams (2×12 pair)
– 542 grams (1×12 pair)

BL-RX610-L – Hydraulic Disc Brake Only
– Left side brake lever
– Gravel-specific brake lever and bracket ergonomics
– Anti-slip coating on brake lever surface

Shimano RX880 Carbon Gravel Wheels

Alongside the mechanical components, Shimano have also brought out an updated carbon gravel wheel. Shimano say that it’s “ purpose-built to handle the rough-and-tumble rigors of dirt road riding.” While it has the same 32mm rim height, they’ve shaved 64 grammes off of it. The rim has a 25mm inner width and is tubeless ready.

Moving to the rear hub it uses a direct engagement hub, borrowed from Dura Ace. This allows you to convert between Micro Spline and HG L2 12-speed freehubs. Spoke count is 24 on both the front and rear.

WH-RX880-TL Carbon Tubeless Wheels specs

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
o Note: Not compatible with 11-speed HG cassettes
– 1394 grams (MICRO SPLINE)
– 1397 grams (HG L2)

Read more on the Shimano website.