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If you thought we were reaching peak gravel and the bike industry couldn’t get much more segmented than it already is, think again. Shimano just doubled down on gravel with the release of GRX, the first purpose-built component group not just for grinding gravel but for any kind of off-road adventure on a drop-bar bike. With claims of improved ergonomics on the brake levers, and gear ratios that work better with fat tires, Shimano says it’s not trying to reinvent the wheel with GRX. Rather, the idea is more about refining the cycling experience and increasing the options so riders can cherry pick the components that will work best for them. To that, Shimano has made GRX compatible with current 11-speed mechanical and Di2 component groups. If you’re happy with everything on your bike but like the look of these new levers, there is no need to buy the entire GRX groupset.
I can already hear the excitement from techies and see the eye-rolling from the purists who think it’s simply an attempt to coerce us into buying new gear. In the interest of full disclosure, that was my reaction when gravel bikes first popped onto the scene. I was part of the group that wondered why road bikes with 23mm tires were no longer good enough for riding off-road. But just like the advent of gravel bikes didn’t mean you couldn’t ride gravel on a road bike, GRX doesn’t make the Di2 on your current gravel bike suddenly inadequate.
The first question that came to mind when learning of Shimano’s new gravel group was, “What can I do with GRX that I can’t do with current road mechanical and Di2 groups?” The answer: GRX isn’t about being able to do more, it’s simply a refinement of the current product, with subtle design tweaks to make it work better under the unique demands that gravel puts on equipment. And since Shimano electronic and mechanical components are already so good for the road, the company decided it was better to make a different, dedicated gravel component group rather than make adjustments to an already successful product.
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Consumers will be happy to learn that all of the new GRX components are cross-compatible within the two levels of GRX—GRX800 and GRX600—but they are also compatible with current mechanical and electronic 11-speed groupsets. GRX400 10-speed is compatible with current Shimano Tiagra-level 10-speed groups.
GRX800 will be available with mechanical and Di2 shifting; GRX600 will be available only with mechanical. Both, however, will be available in 1x and 2x configurations. The 10-speed GRX400 will be available only as a 2x drivetrain.
These aren’t three distinctly different groupsets. In a few cases, there is some overlap in the components. Both the 800 and 600 groups use the same mechanical derailleurs as well as hydraulic brake calipers, which are simply rebranded calipers from Shimano’s road disc brakes. The 600- and 400-level groups share the same cranks but with different chain rings.
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Hydraulic Disc Brakes
Cannondale
Topstone Disc SE 105
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Redesigned Levers
The biggest differences are in the control levers. GRX 800-level Di2 levers received a dramatic makeover from current road Di2 levers. First, the brake lever pivot was raised by 18mm, which Shimano claims will make the brakes easier to use while holding onto the hoods. The hoods themselves are tackier and feature a larger knob in the front to give a more secure handhold and minimize the chances of slipping off when hitting an unexpected bump. The levers also have a textured surface to make them easier to grab in bad weather, and are angled out in a way that’s meant to work well with flared bars.
The mechanical levers have the same textured surface as the Di2 levers, but outside of that remain largely unchanged from current mechanical, hydraulic disc brake levers.
Dropper Post Integration
Riders opting for a 1x mechanical drivetrain can choose a left brake that has no shifting mechanism in it, or they can select a brake lever that also uses a lever to activate a dropper post rather than a front derailleur. Riders using mechanical 2x or Di2 GRX will have to use a bar-mounted remote if they wish to use the dropper post.
Sub Brakes Are Back
In another first, GRX boasts hydraulic sub-brakes. Sub-brakes used to be popular in cyclocross until the advent of hydraulic disc brakes essentially phased them out. Now riders can, again, enjoy the benefits of accessing the brakes while riding on the tops. These will be available both as a set and individually, in case riders don’t feel the need to use both.
Updated Front Derailleur
The front derailleur also boasts some significant differences over current road derailleurs, and it’s here where we start to get into the meat of what Shimano means when it says “specifically tuned for gravel.” The derailleurs are designed to work with a 17-tooth difference between the large and small ring, a much larger gap than current road derailleurs can handle. The largest chainring available is a 48, but paired with an 11t cog and the large tires common on gravel bikes, riders will end up with a top gear that Shimano believes will be suitable for fast riding on smooth roads.
At the other end of the spectrum, you get a 31-tooth inner ring. Shimano settled on that size because it is the smallest ring it could get to work perfectly with the 48t outer ring. Pair that 31 with the smallest available cog on Shimano’s cassettes, which in the case of using 2x is a 34, and you’ll have gearing that is small enough to get you over just about anything.
No new cassettes were introduced with GRX and all current Shimano 11-speed cassettes are suitable to use with the new drivetrains. However, running the 1x configuration will push you toward Shimano’s 11-40 and 11-42 cassettes and the long cage rear derailleur, and going 2x will force you into the medium-cage derailleur and the 11-32 or 11-34 cassettes.
The front derailleur has also been tweaked to work better with fat tires, sitting 2.5mm farther outboard than current road options to increase tire clearance.
Medium- and Long-Cage Rear Derailleurs
Both 11-speed groups have medium- and long-cage derailleur options. Medium-cage derailleurs will work best with 11-30 and 11-34 cassettes, and bumping up to the 11-40 and 11-42 cassettes will require the long-cage derailleur. The RX400 10-speed groupset offers only one rear derailleur, and that one works with Shimano’s 11-32 or 11-36 cassettes. However, all versions of the rear derailleur feature the Shadow RD+ tension adjuster, or clutch as it’s commonly called, for better shifting performance on rough terrain.
1x or 2x Chainrings
Both the RX810 and RX600 groupsets give riders the choice between 1x and 2x drivetrains. RX810 comes with 48/31 rings as a 2x, and 40 or 42t options for 1x. With an eye toward keeping everything as simple and compatible as possible, the cranks actually remain the same between the 1x and 2x options, so riders can upgrade from 1x by adding the chainrings, front derailleur, and left shifter; and riders using 2x can simply remove their derailleur and add the single ring to change to a 1x setup.
RX600 cranks come with 46/30 rings for 2x, and a 40t ring for 1x. RX400 10-speed also uses the RX600 cranks and chainring configurations, but the rings are 10-speed specific.
Availability
Shimano says the mechanical components will start appearing in stores throughout June and July, and the Di2 components will be available sometime in August.
Cranks
RX810 1x: $225, 655 grams
RX810 2x: $225, 722g
RX600 1x: : $147, 753g
RX600 2x: $147, 816g
RX600 1x10-Speed Cranks: $147, 819g
Front Derailleurs
RX815 Di2: $227, 131g
RX810 Mechanical: $52, 94g
RX400 Mechanical: $37, 95g
Rear Derailleurs
RX817 Di2 1x: $320, 322g
RX815 Di2 2x: $287, 288g
RX812 Mechanical 1x: $114, 264g
RX810 Mechanical 2x: $112, 251g
RX400 Mechanical 2x: $63, 303g
Shift Levers
RX815 Di2 Shift Lever Set: $534, Weight TBD
RX810 Mechanical Shift Lever Set: $534, 565g
RX600 Shift Lever Set: $410, 611g
RS400 Shift Lever Set: $330, 613g
Dropper Post Lever: $245, Weight TBD
Brake Levers
RX812 Sub Brakes: $66 each, Weight TBD
RX810 Left Brake Lever (1x): $215, Weight TBD
RX600 Left Brake Lever (1x): $185, Weight TBD
Wheels
650B Tubeless Front: $198
650B Tubeless Rear: $225
650B Wheelset: $420
700c Tubeless Front: $198
700c Tubeless Rear: $225
700c Wheelset: $420
