Any lingering doubts about the staying power of the gravel cycling phenomenon will likely be put to rest following the latest drivetrain release from Shimano. Trumpeting it as the world’s first dedicated gravel component series (which it is), Shimano GRX has been unveiled. Looks like this gravel thing is here to stay.
The Shimano GRX 800 series (think Ultegra level) includes 1×11 and 2×11 drivetrains with mechanical and Di2 electronic options. Top line features include gravel-tuned gearing ratios, off-road friendly ergonomics, dropper post integration, and gravel-specific Shimano GRX aluminum wheels with wider rim profiles.
For simplicity, Shimano GRX uses cassettes and chains that already exist in the Shimano lineup. And in addition to the top end (for now) Shimano GRX 800 series, there are also two lower cost 11-speed components: a 600- series crank and set of shifters, which can be mixed with 800 level parts.
Here’s a part-by-part rundown of all the key components.
Shimano GRX Cranksets
Coming in the form of Shimano’s first ever 48-31T option, the RX810 series cranks offer Shimano’s widest-ever delta between small and large chainrings, a 17-tooth gap. Pair that with an 11-34 cassette, and you get an exceptionally low climbing gear, while still providing a 48-11 ratio that will help you keep speed on downhills and tailwind riding scenarios. The RX810 series cranks also come in a single chainring option.
This can be paired with one of Shimano’s wide ratio 11-40 or 11-42T cassettes, making a solid choice for ’cross or anyone who appreciates simplicity and lower weight. The mid-priced RX600 cranks employ a 2-piece design and are available in 2×11 and 1×11 configurations, and all GRX cranksets employ a +2.5mm chainline for increased tire and frame clearance.
Shimano GRX Derailleurs
The highlight here is that Shimano GRX front derailleurs offer more tire, debris, and frame clearance thanks to a new outboard +2.5mm chainline design also found on GRX series cranks. Because of the outboard chainline, GRX front derailleurs must be used with GRX cranksets and vice versa. RX800 series front derailleurs deliver Shimano’s consistently precise front shifting performance while increasing front gearing range to a 17T delta. They are available in mechanical and Di2 versions.
All Shimano GRX rear derailleurs utilize Shimano’s SHADOW RD+ technology that has been tuned specifically for gravel, enabling riders to adjust the chain stabilizer to match the terrain: engage for a quiet ride with uninterrupted shifting offroad, or disengage for tarmac. Shimano GRX rear derailleurs are available in short (30-34T low) or long cage (40-42T low) options for use with either road or mountain bike cassettes depending on the ideal range. RX800 rear derailleurs are available in both mechanical or Di2 configurations.
Understanding that it’s one thing to bomb down a paved road, but entirely different if that road is gravel, rough, and loose, Shimano GRX includes two new gravel-specific ergonomic hydraulic disc brake lever designs. The new GRX dual control levers feature a gravel-specific ST design for optimal braking from the hoods thanks to the brake lever axis being raised by 18mm, as demonstrated in the image below.
Additionally, the curved brake lever design improves brake feel and power. And to further improve grip the brake levers are encased with a unique anti-slip texture application.
Shimano GRX also includes a new hydraulic sub-brake lever for mounting on the top of the handlebars (think mountain bike levers). This creates more braking options, making the system ideal for cyclocross and/or the modern flared handlebars that are so popular with the gravel sect.
Droppers, Budget Options, and More
Shimano has also allowed for the integration of dropper posts, creating the GRX mechanical ST-RX810-LA left hydraulic disc brake lever that, when used with a 1×11 drivetrain, can control a dropper post while also keeping the cockpit tidy. The use of an integrated cable pulling system allows for 9mm lever throw to operate a dropper post. Shimano GRX also includes GRX600 and 800-series left side hydraulic disc brake levers with no dropper or shift internals for use with 1×11 drivetrains.
Meanwhile, the GRX hydraulic disc brake calipers are flat mount design offered in premium 810 series and 400 series. The calipers are designed to deliver powerful braking performance with ICE Tech heat-dissipating disc brake pads, and feature simple set up and maintenance thanks to Shimano’s one-way bleeding system.
The Shimano GRX ecosystem also includes a 2×10-speed drivetrain for the price conscious that uses a blended specification of RX600 and unique RX400 components. The 10-speed GRX drivetrain utilizes several of the new designs and features of premium GRX series.
Last but not least are the new Shimano GRX aluminum wheels, which are available in 700c and 650b, and feature a wider 21.6mm internal rim width to accommodate wider tubeless tires.
Availability of the new drivetrains will be staggered, with 1×11 and 2×11 mechanical coming in July, followed by Di2 options in August, and finally the sub-levers and dropper lever in September. Price for the complete 2×11 Di2 group is $2356, while 1x Di2 will sell for $2168. Mechanical 2×11 is $1447, with mechanical 1×11 coming in at $1349. Here’s a look at how the various components can be mixed and matched. Click on the image to enlarge.
To learn more head over to bike.shimano.com.