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Shimano finally introduces new electronic 12-speed GRX Di2 gravel groupset

The Japanese giant brings 12-speed Di2 technology to gravel riding, featuring wireless shifting and redesigned shifters

Shimano has expanded its gravel components range by launching GRX RX825 12-speed Di2. With Shimano's Dura-Ace, Ultegra and 105 road groupsets firmly in the 12-speed Di2 realm, the Japanese giant's gravel-specific GRX line was at a bit of a crossroads following the launch of the mechanical GRX RX820 12-speed groupset last August, as electronic GRX was still 11-speed. That is no more though, as the new 12-speed GRX Di2 gets wireless shifting and redesigned shifters. It is currently only compatible with a 2x setup, though. 

2024 Shimano GRX 12-speed Di2 on bike

Last year, Shimano released the much-anticipated GRX 12-speed mechanical groupset. After much speculation, it has now (perhaps inevitably) unveiled the electronically shifting version, which Shimano claims "delivers precise, reliable, distraction-free performance in all conditions". 

Wireless shifting

The first major design change on the new 12-speed GRX Di2 is wireless shifting. An electronic GRX groupset already exists, but it's an 11-speed version with a wired junction box at the handlebar/stem.

2024 Shimano GRX 12-speed Di2 handlebars

> New patent suggests Shimano 13-speed electronic groupsets are coming

Like its 12-speed Dura-Ace, Ultegra and 105 Di2 road-specific siblings, the new GRX Di2 system is semi-wireless with a central internal battery along with wireless shifting.

Wireless shifting eliminates the need for a wired junction box at the handlebar/stem, and the shifters communicate wirelessly with the derailleurs. Wireless means fewer cables to route through the frame, particularly useful on modern road bikes.

Redesigned shifters 

The brake and shift levers are the heart of the Di2 system, allowing you to control the derailleurs as well as the hydraulic brakes. 

2024 Shimano GRX 12-speed Di2 shifter

Shimano's 12-speed GRX Di2 features dual control levers, each equipped with three Di2 buttons for E-Tube Project customisation (more on this below). The third button is positioned near the top of the shifters, on the inside, in a similar location to the new SRAM Red AXS. 

These dual control levers feature a redesigned rounder shape, a refinement aimed at creating a smoother transition from handlebar to hood and ensuring seamless integration with flared handlebars, according to Shimano. 

Similar to all Shimano Di2 shifters, they operate on replaceable coin cell batteries, with an expected lifespan of 3.5 to 4 years.

Satellite shifting

2024 Shimano GRX 12-speed Di2 satellite shifter

Shimano's new Di2 system also allows for accessory shift buttons. Shimano's satellite shifters can be positioned anywhere on your bike's handlebars to enable quicker shifting during efforts without the need to move your hands.

Shadow RD+ rear derailleur 

Like Shimano's mechanical RX820 rear derailleur, the RX825 rear derailleur features Shimano's Shadow RD+ technology, which is designed for more secure chain management during rough rides. 

2024 Shimano GRX 12-speed Di2 Shadow RD+ rear derailleur

It has an on/off switch which aims to make removing the rear wheel easier when it's turned off. When on, "the drivetrain is under additional tension that makes for a quieter ride and more precise shifting", according to Shimano. 

As with all of Shimano's road 12-speed Di2 systems, the rear derailleur also houses the charge port and multi-function button, allowing you to check the battery level. 

E-Tube Project customisation 

'E-Tube Project Cyclist' is Shimano's app which allows you to customise your electric shifting. Whether that's for controlling shifting of either derailleur, or scrolling through screens on your bike computer. 

2024 Shimano GRX 12-speed Di2 front mech

> Your complete guide to Shimano road bike groupsets

The launch of Shimano's 12-speed GRX Di2 groupset also coincides with its new Front Shift Next functionality, implemented through a firmware update. Through the E-Tube Project Cyclist app, you can programme any Di2 button to shift the front derailleur to whichever chainring you're not currently using, and vice versa. This update extends to all of Shimano's 12-speed road Di2 groupsets too. 

Shimano 12-speed GRX Di2 pricing

Obviously, you are interested in what all of this new 12-speed Di2 GRX stuff is going to cost, right? 

There are a number of components that are shared between the mechanical RX820 GRX and Di2 RX820 groupsets, with the crankset, chain, cassette and brakes all being the same whether you choose cables or wires. 

Like with the RX830 mechanical components, you can also use the RX610 cranks and its 46/30T chainrings. 

2024 Shimano GRX 12-speed Di2 groupset

Here are all the individual component prices you need to know:

825-series shifter and disc brake set

  • RX825 GRX Di2 12-speed STI bled with RX820 calliper, right front - £399.99
  • RX825 GRX Di2 12-speed STI bled with RX820 calliper, left rear - £399.99

825-series shifters only 

  • RX825 GRX Di2 12-speed STI - £299.99 each 

825-series derailleurs

  • Rear derailleur RD-RX825 (max 36T for double) with Shadow+ tech (310g) - £324.99
  • Front derailleur FD-RX825 braze 2x12-speed (142g) - £184.99 

Cassette and chain options 

  • The 11-34T cassette is £119.99 and the 11-36T cassette retails for £84.99
  • CNM8100 with Hyperglide tech - £49.99 

RX820 series components

820-series chainsets 

  • The double chainsets are available with 170mm, 172.5mm or 175mm cranks and 48/31 chainrings (710g) and retail for £229.99

820-series brake callipers 

  • BR-RX820 GRX flat mount calliper with adapter 140/160mm front - £79.99
  • BR-RX820 GRX flat mount calliper without adapter rear - £74.99

Emily is our track and road racing specialist, having represented Great Britain at the World and European Track Championships. With a National Title up her sleeve, Emily has just completed her Master’s in Sports Psychology at Loughborough University where she raced for Elite Development Team, Loughborough Lightning.

Emily is our go-to for all things training and when not riding or racing bikes, you can find her online shopping or booking flights…the rest of the office is now considering painting their nails to see if that’s the secret to going fast…

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Secret_squirrel | 3 weeks ago
1 like

they missed a trick in not tweaking the battery to create room for a dropper for this and MTB DI2.

60kg lean keen ... replied to Secret_squirrel | 3 weeks ago

What they need is a wireless droper in 27.5,  this could house the battery.  That is the killer blow that Sram have over Shimano at the moment.

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