Gravel cyclists live to be in the moment. It’s why we roll out of our driveway at dawn. Why we venture down lonely, unknown dirt roads. Why we take on routes and races with unpredictable outcomes. It's also why we demand the best from our gear; expecting precise, reliable, distraction-free performance in all conditions.
Shimano understands—and embraces—these lofty expectations, knowing that even the smallest hiccup can mean the difference between fun and frustration, failure and success. It’s this pursuit that defines the latest addition to Shimano’s growing family of GRX gravel-specific components.
Meet the new 12-speed Shimano GRX Di2 RX825 series, which includes dual control levers refined for comfort and control, a Shimano Shadow RD+ equipped rear derailleur for better chain management, and a gravel-optimized front derailleur for precise shifting.
Electrified 2x12 Gravel Gearing Options
This suite of components brings an electronic option to the 2x12 GRX RX820 items launched last year. Like with the RX820 mechanical components, riders can tailor their gearing with the RX820 crank and its 48/31-tooth chainrings or the RX610 crank with 46/30-tooth chainrings. At the back of the bike, both the HG710 11-36-tooth cassette and the full complement of Shimano 12-speed 11-34-tooth cassettes are compatible.
RX825 compatible gearing options:
• 48/31T RX820 crank
• 11-36T HG710 cassette
• 11-34T R9200, R8100, R7100 cassettes
Any of these gearing combinations pairs perfectly with Shimano’s latest carbon gravel wheels, the WH-RX880. With 25-millimeter internal width and updated DIRECT ENGAGEMENT freehub, the RX880 wheels provide a vital connection between rider and road, however remote or rugged.
All four of the gearing options listed above now benefit from Shimano’s WorldTour-proven Di2 electronic shifting platform. RX825 delivers a wide gear range with tight gear steps so you can spin a comfortable cadence whether hammering at the front of a racing pack, spinning solo down a quiet country lane, enjoying endless dirt road rollers, or tackling a precipitously steep backcountry climb.
Like its 12-speed Dura-Ace, Ultegra, and 105 Di2 siblings, Shimano’s new GRX Di2 is wired where it makes sense, featuring a central, multi-port battery that supplies stable, long-lasting power to both front and rear derailleurs. Smaller diameter wires connect directly from the battery to each derailleur, eliminating the need for junctions and streamlining the build process. The central internal battery also simplifies charging and remains secure over the roughest roads, trails, or whatever less traveled path you choose.
As mentioned earlier, the RX825 rear derailleur features Shimano’s pioneering SHADOW RD+ technology. With its convenient on/off switch, SHADOW RD+ makes removing your rear wheel easy when turned off. When on, your drivetrain is under additional tension that makes for a quieter ride and more precise shifting.
Like the very first GRX groups, the RX820 and RX610 systems employ a wider, +2.5mm chainline for improved tire clearance, allowing you to set up your bike exactly how you want without compromise.
Wireless Gravel-Specific Cockpit
At the front of the bike, Shimano’s 12-speed GRX Di2 features a wireless gravel-specific cockpit where raised hoods with ribbed surface texture and anti-slip brake levers provide ultimate hand security no matter how spicy your ride gets. That secure hand position is further enhanced, as it was with the original GRX RX815 Di2 shifters, with the location of the third Di2 button on the inside of the hood. Whether used as another shift location or for scrolling the screen on your GPS device so you don’t miss the next turn in your adventure, this third button is another way to fully experience Shimano’s electronic Di2 system.
The new Di2 system also allows for accessory shift buttons, another key advantage of electronic shifting. Plugging in one of Shimano’s satellite switches, whether on the tops, drops, or on aero bars, riders can more consistently maintain their effort without the need to move their hands. Like the third button on the GRX Di2 dual-control levers, these satellite switches can be assigned various functions including shifting of either derailleur, to control compatible lights and GPS devices, or as a lap button during workouts.
The new dual control levers also employ a gravel-optimized body shape cross-section for seamless integration with flared handlebars. Rounder in shape, the transfer from handlebar to hood is smoother and creates a larger surface area to help eliminate pressure points. With enhanced comfort, you can extend your day out a little longer.
E-TUBE PROJECT Customization
Using Shimano’s E-TUBE PROJECT Cyclist application, riders can also choose between different shift speeds, customize shift button assignment (what buttons perform which functions), program different shift modes like Synchronized and Semi-Synchronized shifts, fine-tune shifting, and connect with third-party bike computers.
The launch of RX825 also coincides with the debut of Shimano’s new FRONT SHIFT NEXT functionality. With this firmware update, you can now utilize Shimano's user-friendly E-TUBE PROJECT Cyclist app to program any of the RX825 Di2 switches to move the chain to whichever chainring you are currently not in. And you can assign the FRONT SHIFT NEXT function to any of the three shift buttons on the RX825 dual-control lever. The result is simpler, more intuitive shifting for less-experienced riders and quicker decision-making for veteran riders in the heat of competition.
Along with dramatically simplifying the gear-changing process, Shimano FRONT SHIFT NEXT can also free up other switches to handle tasks such as moving through multiple screens on a paired GPS device, turning on and off compatible lights, or hitting the “lap” button on your cycling computer so you can keep your hands securely in place, even during your hardest efforts.
It's these kinds of thoughtful customization options combined with Shimano’s legendarily precise and reliable electronic shifting that help make the expanded family of GRX components the ultimate worry-free choice for all types of gravel cyclists. So go ahead and plan your next ride, race, or multi-day adventure—and know that with Shimano GRX, you'll have the right gear—and gearing—to get you to the finish line, wherever that may be.
