Shimano has expanded its range of gravel components with the launch of the GRX RX825 12-speed Di2. With Shimano Dura-Ace, Ultegra and 105 road groupsets firmly in Di2 12-speed territory, the Japanese giant’s gravel-specific GRX range was at a crossroads following the launch of the GRX RX820 mechanical 12-speed group last August, as the electronic GRX was still an 11-speed. However, this is no longer the case, as the new 12-speed GRX Di2 features wireless shifting and a redesigned shifter. However, it is currently only compatible with the 2x setup.
Last year, Shimano launched the highly anticipated 12-speed GRX mechanical set. After much speculation, it has now (perhaps inevitably) revealed an electronic shifting version that Shimano claims “delivers precise, reliable, distraction-free performance in all conditions”.
Wireless shifting
The first major design change of the new 12-speed GRX Di2 is wireless shifting. The GRX electronics kit already exists, but it’s an 11-speed version with a cable junction box on the handlebars/forehead.
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Like its 12-speed Dura-Ace, Ultegra and 105 Di2 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 cable junction box on the handlebars/stem and the shifter communicates wirelessly with the derailleurs. Wireless means fewer cables running through the frame, which is especially useful on modern road bikes.
Reworked gearing
The brake and gear levers are the heart of the Di2 system and allow you to control the derailleurs as well as the hydraulic brakes.
Shimano’s 12-speed GRX Di2 features two control levers, each equipped with three Di2 buttons to accommodate the E-Tube project (more on that below). The third button is located at the top of the shifter, on the inside, in a similar location to the new SRAM Red AXS.
These dual control levers have a redesigned rounder shape, an improvement aimed at creating a smoother transition from the handlebars to the hood and ensuring seamless integration with the extended handlebars, according to Shimano.
Like all Shimano Di2 shifters, they run on replaceable button batteries with an expected life of 3.5 to 4 years.
Satellite displacement
The new Shimano Di2 system also allows accessory shift buttons. Shimano’s satellite shifter can be placed anywhere on your bike’s handlebars to allow for faster shifting under stress without having to move your hands.
Shadow RD+ rear derailleur
Like the Shimano RX820 mechanical rear derailleur, the RX825 rear derailleur features Shimano Shadow RD+ technology, which is designed for safer chain guidance during rough rides.
It has a switch which aims to make it easier to remove the rear wheel when it is switched off. When engaged, “the drivetrain is under additional tension, allowing for a quieter ride and more precise shifting,” according to Shimano.
As with all Shimano road 12-speed Di2 systems, the rear derailleur houses a charging port and a multi-function button that lets you check the battery level.
Adaptation of the E-Tube project
“E-Tube Project Cyclist” is a Shimano app that allows you to customize your electric shifting. Whether it’s controlling the shifting of either the derailleur or scrolling through the screens on your bike computer.
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The launch of the Shimano GRX Di2 12-speed groupset also coincides with its new Front Shift Next feature, implemented via a firmware update. Through the E-Tube Project Cyclist app, you can program any Di2 button to shift the derailleur to whichever derailleur you’re not currently using, and vice versa. This update also applies to all Shimano 12-speed road Di2 groupsets.
Price Shimano 12-speed GRX Di2
You’re probably wondering how much this new 12-speed Di2 GRX will cost, right?
Few components are shared between the RX820 GRX and Di2 RX820 mechanical kits, with cranks, chain, cassette and brakes being the same whether you choose cables or wires.
As with the RX830 mechanical components, you can also use RX610 cranks and their 46/30T chainrings.
Here are all the individual component prices you need to know:
825 Series Shifter and Disc Brake Kit
- RX825 GRX Di2 12 Speed ​​STI Vented with RX820 Caliper Right Front – £399.99
- RX825 GRX Di2 12 Speed ​​STI Vented with RX820 Caliper Left Rear – £399.99
825 series shifting only
- RX825 GRX Di2 12 Speed ​​STI – £299.99 each
825 series derailleurs
- RD-RX825 derailleur (max 36T for double) with Shadow+ technology (310g) – £324.99
- Derailleur FD-RX825 soldering 2×12 speed (142g) – £184.99
Cassette and chain options
- The 11-34T cartridge is £119.99 and the 11-36T cartridge sells for £84.99
- CNM8100 with Hyperglide technology – £49.99
RX820 series components
820 Series Chain Sets
- Twin chainrings are available with 170mm, 172.5mm or 175mm cranks and 48/31 (710g) chainrings and sell £229.99
820 series brake calipers
- BR-RX820 GRX flat caliper with 140/160mm front adapter – £79.99
- BR-RX820 GRX flat caliper without rear adapter – £74.99