Gravel Grinder News: Shimano Introduces 12spd DI 2 GRX

Note: All images and information for this post were provided by Shimano.

Today Shimano, not surprisingly, introduced its electronic version of the new 12 speed GRX. While it may seem a forgone conclusion after last year's mechanical 12 speed GRX intro, there are a few very interesting details in the new DI2 GRX 12 speed group that are new and notable. 

As many suspected, the new `12 speed GRX follows in the footsteps of its road 12 speed DI2 siblings and has new wireless shifters. The shifters work wirelessly while the derailleurs are still tethered to each other via the battery. Shimano feels that a more reliable, stable connection between the derailleurs is necessary at this point. 

The shifters are all new with a raised hood to help prevent rider's hands from slipping forward off the hoods in rougher or less than ideal conditions. The hood covers are, again, ribbed for better grip for the same reasons. However; what might be missed here is that Shimano has profiled the grip section to fit in the hands better when these shifters are mounted on the flared drop bars so commonplace with gravel riders. 

Shifters/calipers weigh a claimed 830g grams/pair.

The shifters operate using two coin type lithium ion batteries located at the peak of each shifter under the hood grip material. Note the inner shift button.

Battery level can be checked at the shifter. Lifespan of the batteries is estimated at 3.5 to 4 years.

Furthermore, the shifter button/levers are ergonomically designed with rounder edges and larger area for the fingers to find more easily. The big news here is that there is now a third, inner button that can be assigned to do several tasks via Shimano's E-Tube app. These user customizable buttons can be utilized as shifters, computer screen scrollers, or can turn on or off lights that are Bluetooth enabled. 

Interestingly, the third button can also function as a control for Shimano's new FRONT SHIFT NEXT technology which, when enabled, allows the rider to hit a button to shift to whatever front ring they are not in at that time. This means that a rider only has to press a singular button while the front derailleur is commanded to go into whatever chain ring is "next", inner or outer. This should simplify front shifting for riders and theoretically one could customize their shifter to operate front and rear derailleurs from one side, leaving the other side to do other tasks like turning off/on lights, or changing computer pages, for example. 

The FRONT NEXT SHIFT will also be available as upgrades to previous DI 2 Dura Ace, Ultegra, and 105 12 speed groups as well. 

The new third button on the RX 825 levers can be assigned to do several tasks.

Derailleurs And Gearing:

GRX RX825 Di2 compatible gearing options:

• 48/31T RX820 crank
• 46/30T RX610 crank
• 11-36T HG710 cassette
• 11-34T R9200, R8100, R7100 cassettes

Note: At this time there is no word on any 1X group. (See my "Comments" section below)

The new GRX DI2 rear derailleur is the communications hub for the new GRX system.

The new Shimano RD+ Shadow Rear Derailleur features the chain stabilization system which is switchable on/off via a lever for easy wheel removal. It also has the system's charge port and can communicate with the E-Tube app via Bluetooth from any smart phone. Riders can customize settings using this app, check battery levels, and enter adjustment mode for each derailleur. Weight for the rear derailleur is listed at 310 grams. 

The front derailleur features the now standard for GRX 2.5mm offset of the chain line to accommodate larger tires used on gravel bikes and for better mud clearance. Claimed weight is 142 grams. This derailleur can be configured to operate in the aforementioned FRONT SHIFT NEXT mode and in the other more common DI2 modes.

 Comments: Following are my own comments on this introduction and these comments may not reflect Shimano's or anyone else's opinions. 

This was expected, obviously, especially after the introduction last year omitted the DI2 12 speed GRX, which everyone was expecting would be released first. Thinking about this, the omission of any 1X DI2 news may also be a planned thing with a later introduction to follow this one. 

I know some will quibble about the lack of pie-plate sized rear cassette cogs and that front derailleurs are antiques that should be relegated to the dust bin, but I think that is flawed thinking for several reasons. Let's just say that there are alternatives out there and that - generally speaking - most brands have both flavors, SRAM or Shimano,  at your disposal. You don't HAVE to buy this new GRX 825. And don't forget that there is a mechanical 1X GRX 12 speed that does support those big gearing ranges.

Also, and this may come as a shock, but since GRX 825 is geared toward racing, and racers tend to like 2X more, you might not see 1X until later, if it is coming out. 

I also am thinking that Shimano is carefully walking out these new introductions so as to not overwhelm an already 'drowning in inventory' marketplace that needs to find its footing yet. Had we been in a normal economic cycle I think that the mechanical and DI2 groups would have been launched simultaneously. 

But another theory is that this new FRONT SHIFT NEXT is an alternative to 1X. Think about it: You already have to operate a shifter anyway, so by simplifying the front shifter to being a one-push operation with no resistance to doing that, and then combining that on the lever that also operates the rear shifter, which can be done via the E-Tube customization, one could theoretically gut the left shifter, (assuming right handed rider, or you could do the opposite for Lefty's) save weight, and have a "1X Plus" set up which could utilize two front rings, keep your chain line straighter, and allow you to choose when the front switches gears. 

Whatever the case may be with the lack of a 1X GRX 825 at this time, the DI2 option is definitely welcomed and should find fans easily. 

PRO Discover Aero Carbon Handlebar:

In conjunction with the new release of the GRX Di2, PRO brand has released the new aero carbon bar which brings the benefits of Dyneema infused carbon, aerodynamic profiling, and semi-internal routing to gravel riders. 

The handlebar will be available in 40cm, 42cm, and 44cm widths with matching PRO Discover alloy stems in seven lengths ranging from 60mm to 120mm in length. These stems have a flippable -10°/+10° configuration for a great compliment to the current PRO stems which are featuring plus/minus six degree design. The PRO10 Stems are made in alloy to match perfectly with the new PRO Discover Aero Carbon Handlebars. 

These bars have a 12° flare and feature minimal drop at 100mm. The tops are flattened and sweep forward a bit for more comfort and areo purposes, of course. All components are based on a 31.8mm clamping diameter and should be available now from PRO dealers. Furthermore; these new PRO offerings are the first to be tested with a combined Road and MTB testing protocol that is being called  the PRO Gravel Standard. Look for Professional rider Lauren ten Dam to be riding these components at the upcoming Unbound event in Emporia, Kansas.

Thanks to Shimano for providing this information.