While the dust has yet to settle around Shimano’s brand-new XTR Di2 Wireless mountain bike groupset – which our sister magazine ENDURO has already tested thoroughly – the Japanese manufacturer is already turning its attention to the gravel segment. With the launch of the GRX RX827, Shimano bring their popular gravel-specific groupset into the wireless era. At first glance, the update may seem modest – after all, it’s only the derailleur that’s been replaced. But it’s precisely this detail that could have far-reaching consequences.
Just a week after American rival SRAM launched its new RIVAL and FORCE XPLR 1×13 groupsets, which offer a wider gear range and long-standing mullet compatibility, Shimano’s update feels almost like a delayed counterattack. This, despite the fact that Shimano only revised their gravel-specific lineup last year – though genuine leaps in innovation have remained elusive.
So is the RX827 essentially a technological trial balloon – and perhaps even a quiet signal that a wireless DURA-ACE or ULTEGRA could be on the horizon? Shimano are staying vague for now. But one thing is clear: the cables have disappeared. And with them, perhaps, the final barrier on the road to a fully wireless future for drop-bar bikes.
Just a Rebranded XTR Derailleur? – A Closer Look at the New Shimano GRX Di2 Wireless
It may look like an XTR – and in many ways, it is. But the arrival of the new GRX Di2 Wireless marks more than just a simple rebranding exercise. With this launch, Shimano introduce their first fully-wireless 1×12 Di2 groupset designed specifically for gravel use – a significant milestone for drop-bar enthusiasts.
At the heart of the system is a redesigned derailleur with an integrated battery. With this move, Shimano are saying goodbye to the traditional Di2 frame-mounted battery and fiddly internal cable routing in the gravel segment. Instead, the power source now sits directly inside the RD-RX827’s housing – protected, removable, and externally rechargeable, much like SRAM’s approach. Shimano claim a range of 700 to 1,000 km per charge, depending on riding style and shifting frequency. Self-charging systems like Shimano’s new Q’Auto remain off the table for gravel, at least for now.
As usual, the system can be customised via the E-Tube app and is compatible with all 12-speed wireless shifters – whether from the GRX, DURA-ACE, ULTEGRA, or 105 Di2 series. Flat-bar riders are covered too: the RX827 works seamlessly with XTR and DEORE XT levers. The result is a flexible ecosystem that finally brings Shimano closer to SRAM’s modular approach – but without the requirement for a UDH. The RX827 can be mounted on virtually any frame, including older models.
Technically, the GRX derailleur closely mirrors the XTR: the low-profile, wedge-shaped design is intended to deflect impacts rather than snag. In the event of a collision, the servo motor automatically disengages and resets itself.
Also new is the chain management system. Instead of relying on a clutch mechanism, Shimano use a dual-spring construction to increase chain tension. Whether this holds up under rough, real-world conditions remains to be seen. What’s clear is that the RX827 is offered exclusively in an SGS long-cage version, compatible with 10–51T cassettes. Paired with 40 or 42-tooth chainrings, the setup feels a bit limited, especially for riders looking for more customisation. Expanding these options would have been a welcome move.
At 449 g, the RX827 derailleur is around 10% heavier than the XTR version, which tips the scales at 408 g – but with a retail price of €489.95, it’s significantly more affordable than the XTR derailleur, which costs €664.95. So the question “Why not just go for XTR?” is certainly justified – but not without context.
The new GRX RX827 isn’t a gamechanger for racers; it lacks the fine-tuned gearing options and customisation some riders demand. A 10–51T cassette does offer an enormous range, but with only two chainring options available, fine-tuning is limited – at least straight out of the box. Riders chasing maximum weight savings or looking to run smaller cassettes like a 9–45T might be better served by the XTR or XT with a short cage. Which raises the question: why doesn’t Shimano offer the short cage format for gravel as well?
Then there’s the emerging playground of mullet setups. What was once a DIY workaround is now a fully supported option. Combine a GRX chainring with an MTB cassette – and optionally flat-bar shifters– and you’ve got yourself a rugged, wireless adventure bike with either drop or riser bars. Shimano’s new GRX Wireless makes it possible.
On test: The New Shimano GRX Di2 Wireless
Just a few months after its official launch, we got our hands on a test sample of the new GRX RX827 — which makes us one of the first German-language outlets to put it through its paces. And where better to test a gravel-specific groupset than on a gravel outing? We took it over roots, through fields and meadows, and into muddy forest trails to see how Shimano’s first wireless gravel drivetrain holds up in the real world — far from lab conditions and polished press releases.
At first glance, the rear mech looks solid and well built. The design draws heavily from the existing GRX 1×12 and 2×12 Di2 groupsets, as well as Shimano’s latest XT and XTR Di2 MTB components. Compared to their predecessors, these newer drivetrains have a bulkier appearance, which is largely due to the integrated battery. Anyone familiar with Shimano will feel right at home — although there are a few new touches to discover.
Shifting performance is exactly what you’d expect from Shimano: crisp, precise and direct. Even under load, the derailleur shifts without delay or annoying noises. In that respect, Shimano deliver the high standard we’ve come to expect from their Di2 technology.
However, removing the battery takes a bit of patience. To take it out, you have to flick a small lever and then remove a cover. This can be a hassle if you’re on the move — especially if the little cover falls off during the process.
Compared to SRAM’s more user-friendly AXS batteries, Shimano’s approach does feel a bit finicky. Still, it has one clear advantage over the traditional central Di2 battery hidden inside the frame: you don’t need to run any cables at all.
The brake hoods are unchanged from the GRX Di2 2×12. The only difference is that the left shifter has no buttons, simply because this is a 1x-specific setup. In terms of braking ergonomics, Shimano stick to their one-finger philosophy, which generally offers solid control. However, nothing has changed since the last GRX release — and when it comes to ergonomics, SRAM still have the upper hand.
Who should take a closer look at the new Shimano GRX Di2 Wireless?
The new GRX is a well-rounded solution for anyone after a wireless 1x drivetrain with reliable Di2 technology. It ensures precise shifting, intuitive operation and performs just as well in a race setting as it does on long adventures. What really stands out is the fast, quiet shifting and how seamlessly it integrates into the existing Shimano ecosystem. The only real compromise lies in the cassette range: if you’re after maximum gearing spread, a 1×13 setup might suit you better. But for most riding scenarios, the 10–51 cassette provides more than enough range.
Conclusions about the Shimano GRX Di2 Wireless
With the new GRX Di2 Wireless, Shimano finally brought wireless tech to the gravel world — with a solid build, quiet operation and precise shifting. Battery handling is a bit finicky, while ergonomics remain unchanged from the previous GRX generation. When it comes to one-finger operation, the American competition currently feels more refined. That said, on our test bike — the Avona Callis — the GRX Di2 Wireless still delivered a strong performance, particularly in terms of braking power and shift speed. Shimano are clearly pointing the way forward: no more cables, and greater modularity. But while the gravel setup is now wireless in its 1x configuration, Shimano are still relying on their proven wired Di2 system on the road — at least for now. When they’ll make the leap to wireless there remains to be seen.
More info at shimano.com.
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Words: Jan Fock Photos: Jan Fock, Jan Richter
