7th May 2019 / Comments (0)

Shimano Goes Gravel – New GRX Series

shimano gravel groupset

Shimano GRX (Updated 09/05/2019 with component prices and availability dates, see below)

Shimano has finally gone 1x in one of the most anticipated moves of the decade. While SRAM has dominated the gravel drivetrain market with the superb Apex, Rival and Force 1x groupsets, Shimano has stuck firmly to supporting the front mech.

Until now that is. Maybe the best news is that the new range of long-cage GRX rear mechs can comfortably run a 11/42t cassette, which opens up a whole wealth of options for the gravel cyclist. Still a firm supporter of the front mech? Don’t worry, they are not killing it off just yet.

Shimano gravel groupset

Shimano plays catch-up. Hello single ring!

Most importantly, when can you get your gritty mitts on the new GRX components? EU availability for the mechanical series is June. With Di2 specification due to arrive in August.

With mechanical and electrical options, 10 and 11 speed, 1x and 2x, there’s lots to digest. So without further ado, here’s the info from Shimano.


Featuring multiple options including double and single drivetrains, mechanical or electronic shifting, 11 and 10-speed drivetrains, dropper post integration and wide or close-range gear ratios dedicated to every style of gravel and adventure riding.

Following a comprehensive research, testing and development process, bringing together global feedback from riders on trails, bridleways, pavement and paths at all levels of competitiveness, Shimano introduces a new component series known as GRX; the world’s first dedicated family of gravel/adventure components built for both fast riding and assured capability on loose surfaces.

The GRX in full

Shimano GRX in all it’s gravelly glory.

GRX offers RX800, RX600 or RX400-series components with 1×11, 2×11 and 2×10 drivetrains and mechanical and Di2 electronic shifting options, allowing riders to tailor their mixed surface riding experience and explore beyond their usual limits to pursue a wide range of terrain.

Developing the series took Shimano’s development team well outside traditional confines to create a platform that addresses riders’ needs now and into the future. Be it gravel riding, modern adventure road riding, or bikepacking, Shimano GRX provides options ranging from gravel-tuned gearing ratios to custom ergonomics, dropper post integration and gravel-specific GRX wheels with wider rim profiles.

Shimano GRX lifestyle shot

A lifestyle shot of gravel cycling that doesn’t include gravel! We can relate to that.

The components

Diving into the detail, GRX includes three crankset options – 1×11, 2×11 or 2×10-speed – plus front and rear derailleurs, disc brake calipers with an in-line brake lever option, and left and right STI hydraulic levers, coming in either Di2 shifting or mechanical shifting options.

These components employ Shimano’s class-leading drivetrain technologies from both the road and mountain bike side to deliver the hallmark shifting precision and stability for which the company is known. With GRX the net result is a smooth and quiet-running drivetrain that is specially tuned for the unique characteristics of gravel terrain, riding positions and gravel bicycle designs.

GRX Cranksets: The GRX cranksets are built for tackling different riding terrains and riding styles, all coming with a +2.5mm chainline for increased tire and frame clearance. GRX single ring cranksets offer the simplicity of shifting only on the rear cassette (options include RX800/600 40T chainrings or the RX800 42T chainrings) and are delivered with Shimano’s Dynamic Chain Engagement tooth profile on the front chainring to offer increased chain retention over bumpy ground.

The 1x crankset

Single ring cranks…

Meanwhile the GRX double chainring RX810 crankset employs a 17-tooth gap which, at 48-31T, is the company’s widest-ever gear ratio. Together with the additional RX600-11/10 46-30T options, the double cranksets give big enough gear ratios for tackling the steepest climbs and pinning the steepest descents.

Shimano GRX double

… and doubles

GRX Front derailleurs (FD): Complementing the cranksets, the Di2 or Mechanical  front derailleurs are built with 2.5mm more outbound clearance for wider tires (up to 42mm) to cope with riding on rough roads. This means GRX front derailleurs must be combined with Shimano GRX +2.5mm cranksets.

Both RX800-series mechanical and Di2 front derailleurs are built to accommodate Shimano’s widest 17T front chainring 48-31T gear ratio whilst the FD-RX400 10-speed derailleur accommodates the 16T chainrings found on the RX600 46-30T 10-speed cranksets. Shimano Di2 FD’s can be perfectly adjusted using Shimano’s simple and integrated controls whilst mechanical FD’s bring an extremely light front shifting feeling with an ergonomic power curve, toggle link construction for more cable routing options and an integrated cable tension bolt for precise and easy adjustments.

Front mech GRX style

That GRX front mech. The component everyone is least excited about?

GRX Rear derailleurs (RD): Adopting the technology introduced in 2018’s RX rear derailleur, the GRX Di2 RDs (RD-RX815/RX817) or mechanical RDs (RD-RX810/RX812/RX400) are designed for silent, smooth and reliable shifting on rough terrain with a chain stabilising system known as SHADOW RD+ to manage ‘chain chatter’, minimise unnecessary derailleur arm movement and provide uninterrupted shifting performance. GRX comes with the choice of four derailleurs depending on which cassette and gear shifting operation you choose.

Shimano GRX rear mech

We like the angle of your dangle.

Riders using an Ultegra, 105 or Tiagra level 11-30/34T cassette will need to use the short cage Di2 RD-RX815 or mechanical RD-RX810 rear derailleur, whilst riders choosing a Deore XT, SLX or Deore level 11-40/42 cassette will need to use the longer cage Di2 RD-RX817 or mechanical RD-RX812 RD, both of which come with a pull ratio similar to Shimano’s road derailleurs.

GRX STI levers: GRX shifting comes courtesy of dedicated gravel-specific ergonomic levers featuring an 18mm higher axis point, curved brake lever profile and anti-slip textured finish which can be gripped with assurance over rough terrain.

Shimano GRX shifters

Those GRX Shifters in the real world.

To integrate the use of dropper posts in gravel riding, Shimano created the GRX mechanical ST-RX810-LA left hydraulic disc brake lever that, when used with a 1×11 drivetrain, can control a dropper post whilst also keeping the cockpit tidy. The integrated cable pulling system has a 9mm lever throw to operate dropper posts with cable heads at the shift lever. Shimano GRX also includes 1×11-specific RX800 and RX600-series left side hydraulic disc brake levers with no dropper or shift internals, including the 1×11 Di2 left-hand lever (ST-RX15), which comes with three buttons (two side buttons and a hood top button) for operating ancillary functions such as lights or 3rd party computers.

Shimano GRX sifters

GRX shifters. Enjoying a little bar flare.

GRX Braking systems: A primary concern of gravel riders is having enough brake power to control speed on steep and sudden descents. That’s why, at the top tier of the GRX family, one variant of the RX800-series brake levers (ST-RX815) offers Servo Wave technology coming from Shimano’s mountain bike brakes. This provides a stronger braking feeling with greater modulation options for more aggressive riding. The non-Servo Wave versions still provide an excellent level of disc brake stopping power, akin to Ultegra, 105 or Tiagra road disc brakes respectively.

Brake caliper shot GRX

Heel rub. It happens to everyone.

An additional braking option comes with an inline hydraulic sub-brake lever (BL-RX812-L/R) which connects to the main hydraulic line running to the front and/or the rear caliper. The sub-brake lever is designed to be mounted on the handlebar next to the stem offering options for braking when riding with hands on the tops.

Shimano GRX gravel brake caliper

Gravel anchors…

The GRX calipers (BR-RX810/400) echo the design of Shimano’s flatmount road calipers to deliver powerful brake performance, taking features like one-way bleeding and ICE TECHNOLOGIES heat-dissipating finned brake pads and rotors to offer efficient cooling and long-lasting brake performance.

Gravel-specific Wheelset: To complete the experience, Shimano tips its cap to the experimental spirit of gravel with two gravel/adventure-inspired 12mm E-THRU axle wheel sets. The 700c or 650b tubeless-ready wheelsets offer an optimal balance between weight, stiffness and gravel durability, bringing a wide 21.6mm inner rim width, comparable with MTB XC wheels and an off-set rim height of 22mm.

Shimano GRX Gravel wheelset

These wheels are gravel specific…

For everything Shimano, head on over to: bike.shimano.com


Online retailer Tredz have just listed the GRX range in their webshop. Component prices and the dates they are due in are listed in the table below.




Shimano GRX RS470 100 X 12Mm Front Hub 28/32H



Shimano GRX FD-RX400 10 speed Braze-on Front Derailleur



Shimano GRX RX400 Disc Brake Caliper (Front)



Shimano GRX RX400 Disc Brake Caliper (Rear)



Shimano GRX FD-RX810 11 Speed Braze-On Front Derailleur



Shimano GRX BL-RX812 Sub Brake Lever (Cross-top L/RHS)



Shimano GRX RD-RX400 10 Speed Shadow+ Rear Derailleur (2×10)



Shimano GRX RX810 Disc Brake Caliper (Front)



Shimano GRX RX810 Disc Brake Caliper (Rear)



Shimano GRX RD-RX810 11 Speed Shadow+ Rear Derailleur (2×11)



Shimano GRX RD-RX812 11 Speed Shadow+ Rear Derailleur (1×11)



Shimano GRX600 10 Speed Double chainset



Shimano GRX600 11 Speed Single/Double chainset



Shimano GRX 400 10 speed STI Levers
Front Shifter (Hydraulic) Levers only



Rear Shifter (Hydraulic) Levers only


Pair Hydraulic Levers only


Front shifter ever w. BR-RX400 flat mount calliper


Rear shifter lever w. BR-RX400 flat mount calliper


Shimano GRX RX600 1x STI Levers
1×11 compatible-STI Hydraulic lever only



1×11 compatible-STI Hydraulic lever & BR-RX400 caliper


Shimano GRX 600 11 speed STI Levers

Front Shifter (Hydraulic) Levers only


Rear Shifter (Hydraulic) Levers only


Pair Hydraulic Levers only


Front shifter ever w. BR-RX400 flat mount calliper


Rear shifter lever w. BR-RX400 flat mount calliper


Shimano GRX RX810 1×11 speed STI Levers
1×11 Hydraulic Lever only



1×11 Hydraulic lever & BR-RX810 flat mount calliper


1×11 & Dropper post release hydraulic lever


1×11 & Dropper release & BR-RX810 flat mount calliper


2×11 Hydraulic Lever only (Front or Rear)


2×11 Hydraulic Levers only (Pair)


2×11 Hydraulic Levers & BR-RX810 Caliper (Front or Rear)


Shimano GRX RX810 11 Speed Chainset (Single/Double)



Shimano GRX WH-RX570 tubeless ready RR wheel (650b/700)



Shimano GRX WH-RX570 tubeless ready FR wheel (650b/700)


Shimano GRX FD-RX815 Di2 Braze-on Front Derailleur



Shimano GRX RD-RX815 Di2 Shadow+ Rear Derailleur (2x)



Shimano GRX RD-RX815 Di2 Shadow+ Rear Derailleur (1x)



Shimano GRX RX815 Di2 Hydraulic 11 speed STI Levers
2×11 STI Levers Only (Front or Rear)



2×11 STI Levers Only (Pair)


2×11 STI Lever & BR-RX810 flat mount calliper (Front or Rear)


Last modified: 9th May 2019

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