Shimano creates a whole new wireless GRX groupset with just two new components

June has seen a lot of action from Shimano. We’ve covered a brand new Shimano XTR groupset, the first ever wireless groupset from the Japanese giant, and hot on its heels was the launch of the lower-tier Deore XT wireless groupset.

Both of these groupsets were all-new; a systemic overhaul, which kind of explains why Shimano decided to clean-slate both ranges at once. Now Shimano has released a new GRX wireless Di2 groupset, but unlike XTR or XT it’s not really a new groupset at all, but rather a combination of a new rear derailleur and a new left hand shifter that, in combination with current component offerings, can create a fully wireless, 1x gravel groupset.

Two new components, one new groupset

Shimano’s GRX gravel groupset already exists in several guises. There’s the flagship 2x12 Di2 version, and second-tier cable-actuated 1x and 2x12 offerings. This means there are a lot of parts out there with which to mix and match to make a new setup.

Effectively, Shimano has launched a new wireless rear derailleur, the RD-RX827, which draws heavily from the designs of the XTR and XT rear derailleurs. This can be combined with the cranks and cassette from the cable-actuated GRX drivetrain, the wireless right-hand shifter from the 2x Di2 drivetrain, and a brand new, gutted BL-RX825-L left-hand shifter, which is devoid of buttons.

Users could conceivably also opt to use the dropper-specific GRX lever, whereby the brake lever also swings to actuate a mechanical dropper post, or simply run a standard pair of 2x levers and use the redundant Di2 shifter paddles to augment the bonus buttons and control things like their computer screens.

A new wireless rear derailleur

Unlike XTR, which offered two new derailleurs (short cage and long cage), this new GRX RD-RX827 rear derailleur is only available in a long cage version. As it is only really designed to work with the micro spline 10-51t cassette, though this should work with other 12-speed cassettes.

The gearing range isn't set in stone, however, as the existing 1x GRX cranksets are offered in 40t or 40t chainring sizes, and for those looking to create hybrid drivetrains, it is possible to use mountain bike standard cranksets to get a lower gear range.

Like the XTR and XT derailleurs, it features a removable battery for off-bike charging and a design that is claimed to help alleviate the risks associated with rock strikes. Rounded edges aim to stop it catching so badly on protruding trailside objects, and the new impact recovery function automatically returns the derailleur to the position it was in before the impact occurred, meaning you should be able to just keep pedalling.

Add to this a new dual-spring design which aims to improve chain retention, also ported over from the MTB derailleurs, and it seems like Shimano has been speccing its gravel components for ever-rougher terrain.

The new derailleur weighs in at 449g and boasts a battery range of 700-1,000km.

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A new dummy lever

While it is possible to use the new wireless rear derailleur with the current 2x shifter hoods, it would leave you with two redundant shifter paddles on the left-hand shifter. One could use these to control a computer, a set of smart lights, but three spare buttons (including the bonus upper one) are likely too many for most people.

As such, Shimano has also launched the BL-RX825-L left-hand GRX shifter, which features the same ergonomics as the 2x Di2 shifters but is totally devoid of features besides a hydraulic brake lever. This only saves 19.5 grams, with the shifter weighing in at 188g, but reduces the complexity and saves your fingers from reaching for buttons that won’t do anything.

This leaves the current RX825 right-hand lever to take control of all the shifting and bonus button duties, with the remaining extra on the inside face of the upper part of the hood.

At present, pricing and availability details haven't been shared.