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Shimano’s GRX groupset could be the perfect pick for your next gravel adventure

Tuesday, May 7th, 2019 3:50pm
Category: Latest News

Shimano have just released details of their new GRX groupset, aimed at the ever-growing adventure/gravel bike market.

A blend of the company’s hugely popular road and mountain bike groupset offering, Shimano GRX is available in many different configurations – including 2×11 speed, 2×10 speed and 1×11 speed – we’ve included a full breakdown of the possible configurations below.

Shimano GRX groupset at a glance:

  • Includes double and single drivetrains
  • Mechanical or electronic shifting
  • 11 and 10-speed drivetrains
  • Dropper post integration
  • Wide or close-range gear ratios
  • Shimano Ultegra = Shimano RX800 (Ultegra mechanical shifters: ST-RX810, Ultegra Di2 shifters: ST-RX815)
  • Shimano 105 = Shimano RX600
  • Shimano Tiagra = Shimano RX400


Here’s a breakdown of the possible configurations with Shimano GRX:

So what makes this a ‘gravel’-specific groupset?

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

Shimano GRX STI levers

Let’s start with the Gravel ST shifter. GRX shifting comes courtesy of dedicated gravel-specific ergonomic levers (Di2: ST-RX815 or Mechanical: ST-RX810/RX600/RX400, ST-RX810-LA) featuring an 18mm higher axis point, curved brake lever profile and anti-slip textured finish which can be gripped with assurance over rough terrain.

A textured surface and taller hoods prevent hand slippage, while the brake lever axis has been raised by 18mm for easier braking. The brake lever has been curved for extra confidence during off-road descents too.

Shimano’s Servo Wave action, made famous in its many mountain bike braking systems, is also employed at the top level GRX to offer supreme braking power with very minimal lever action. This provides a stronger braking feeling with greater modulation options for more aggressive riding.

The non-Servo Wave version, or the RX600 and RX400-series levers, still provide an excellent level of disc brake stopping power, similar to Ultegra, 105 or Tiagra road disc brakes respectively, so you won’t be disappointed.

Shimano GRX sub-brake levers

Sticking with the brakes, Shimano GRX also allows you to run sub-brake levers, allowing you to brake in an upright position. This additional braking option 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.

Down at the business end, the brake caliper provides excellent heat dissipation and when it comes to maintenance, has an easy-to-use one way bleeding system.

Integrated dropper post lever

Dropper posts are pretty much a must-have on modern mountain bikes, and any gravel ride with a fair amount of descending will be made all the more enjoyable with the option to drop and raise your saddle on-the-fly. 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 Shadow RD+

Adopting the technology introduced in 2018’s Shimano RX rear derailleur, the GRX Di2 RDs (RD-RX815/RX817) or mechanical RDs (RD-RX810/RX812/RX600) 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.

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.

We’re looking forward to giving the new gravel groupset a go – let us know what you think of it down in the comments section below.

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