Shimano believes in gravel
It's not every day you get a new groupset from Shimano. With the "GRX", this rare case has occurred: Shimano presents its own groupset for gravel bikes. And with several options, including single and double cranks, mechanical or electronic shifting, 11- and 10-speed drivetrains and the integration of dropper posts.
In developing the groupset, the Shimano development team has gone far beyond traditional boundaries to create a platform that meets the needs of riders today and in the future. Whether gravel riding, modern adventure road riding, bikepacking or meeting the needs of demanding cyclocross riders, the Shimano GRX offers options ranging from the right gear ratios for a wide variety of terrain to individual ergonomics, dropper post integration and dedicated GRX wheels with wider rim profiles, according to Shimano.
To go into more detail, GRX offers three crankset options - 1x11, 2x11 or 2x10-speed - as well as front and rear derailleurs, disc brake calipers with inline brake lever option and left and right STI hydraulic levers available with either Di2 shifting or mechanical shifting. These components utilize Shimano's drivetrain technologies from both the road and mountain bike side to deliver the trademark shifting precision and stability the company is known for. With GRX, the result is a smooth and quiet drivetrain that is specifically tuned to the unique characteristics of gravel terrain.
For simplicity, Shimano GRX recommends the use of Shimano MTB (Deore XT, SLX or Deore) or Road (Ultegra, 105, Tiagra) cassettes and chains already available in the Shimano line. In addition to the category-leading Shimano GRX 800 series, there are also cheaper 11-speed components, a 600 series crank and a shifter set that can be seamlessly combined with parts from the 800 series, as well as 10-speed cranks, front derailleurs and shift/brake sets. This means that anything is possible, from a premium-level lightweight GRX groupset to a GRX workhorse on a budget price plan.
The GRX cranks are designed for a wide range of riding situations and riding styles and all feature a +2.5 mm chainline for more tire and frame clearance. GRX single cranks offer the simplicity of shifting on the rear cassette only (options include RX800/600 40T chainrings or RX800 42T chainrings) and come with Shimano's Dynamic Chain Engagement tooth profile on the front chainring for increased chain retention on rough terrain. Meanwhile, the GRX RX810 double chainring crank features a 17-tooth jump, which at 48-31T is the company's largest ratio to date. Together with the additional RX600-11/10 46-30T options, the double cranksets offer big enough gearing to tackle the steepest climbs and the steepest descents.
GRX crankset weights: 1x11: FC-RX810-1: 655g, FC-RX600-1: 753g. 2x11: FC-RX810-2: 722g, FC-RX600-11: 816g, FC-RX600-10: 819g
In addition to the cranksets, the Di2 (FD-RX815) or Mechanical (FD-RX810/RX400) front derailleurs are equipped with 2.5 mm more initial clearance for wider tires (up to 42 mm) to withstand riding on rough roads. This means that GRX front derailleurs must be combined with Shimano GRX +2.5 mm cranksets. Both the RX800 series and Di2 series chainrings are designed to accommodate Shimano's widest 17T front chainring 48-31T gear ratio, while the FD-RX400 10-speed chainring accommodates the 16T chainrings of the RX600 46-30T 10-speed cranksets.
GRX derailleur weights: FD-RX815-F: 131g, FD-RX810-F: 94g (pictured), FD-RX400: 95g
GRX rear derailleurs (RD):The GRX Di2 RDs (RD-RX815/RX817) or mechanical RDs (RD-RX810/RX812/RX400) are designed for quiet, smooth and reliable shifting on rough terrain with a chain stabilization system called SHADOW RD+ to control the chain
.GRX STI levers: Shimano launches the GRX drivetrain with Gravels-specific ergonomic levers (Di2: ST-RX815 or mechanical: ST-RX810/RX600/RX400/RX400, ST-RX810-LA) with curved brake lever profiles and a non-slip, textured surface that can be operated with confidence even on rough terrain. The ST-RX815 also has an 18 mm higher axle point.
To integrate the use of dropper posts in gravel riding, SHIMANO developed the GRX mechanical ST-RX810-LA left hydraulic disc brake lever, which can control a dropper post when used with a 1x11 drivetrain while keeping the cockpit tidy. The integrated cable pull system has a 9mm lever stroke for actuating vario kits with cable heads on the shifter. SHIMANO GRX also includes 1x11-specific RX800 and RX600 series left hydraulic disc brake levers without drop or shift internals, including the 1x11 Di2 left lever (ST-RX15), which is equipped with three buttons (two side buttons and a hood top button) for operating additional functions such as lights or third-party computers.
GRX STI shift/brake lever weights: ST-RX815-L/R Di2: 565g, ST-RX810-LA left side vario lever: TBDg, ST-RX600-L/R: 611g, ST-RX400-L/R (10-speed): 613g
A major concern for gravel riders, according to Shimano, is having enough braking power to control speed on steep and sudden descents. For this reason, a variant of the RX800 series brake levers (ST-RX815) offers servo wave technology, which originates from Shimano's mountain bike brakes. This provides a stronger braking feel with greater modulation options for more aggressive riding. If you prefer the RX810 Non-Servo Wave version or the RX600 and RX400 series levers, they still provide an excellent level of disc brake stopping power, similar to Ultegra, 105 or Tiagra road disc brakes.
An additional braking option is an in-line hydraulic auxiliary brake lever (BL-RX812-L/R), which connects to the main hydraulic line that rides to the front and/or rear caliper. The lower link lever is designed to be mounted on the handlebars next to the stem and offers options for braking when riding with your hands on the tops.
GRX hydraulic disc brake lever weight: BL-RX812L/R: TBDg
The mechanical version of the GRX should be available from June, the Di2 version from August.
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Note: This content has been automatically translated from German. Please report any incorrect translations.