Shimano Announces 105 Di2 Group

Shimano Announces 105 Di2 Group – by Guitar Ted

Shimano brings its wireless shifting, 12 speed Di2 to the 105 level.

The Shimano 105 component group has arguably been the workhorse road bike component group since its introduction in the early 1980’s. The component group is known for its value to the rider but also for its functionality, which has proven itself over the years in many applications. Now riders can experience the advantages of electronic shifting in a more attainable package via this new introduction of 105 Di2.

This is a road bike group, yes, but we feel that this introduction has implications for the gravel going cyclist as often developments in one area of Shimano’s range end up becoming parts of other component groups. Just like with this example of 105 Di2. It doesn’t take much imagination to see that some of these features would be welcome additions to Shimano’s GRX range.

Note: Images and information in this post were provided to Riding Gravel by Shimano. All prices listed are subject to change and are in USD.

What It Is: Shimano debuted a new Di2 system with its 12 speed Dura Ace and Ultegra groups not all that long ago. Shimano could have easily made the 105 Di2 an 11 speed group with the older features, but instead, they have utilized the same features from the upper groups in the new Di2 105. So, you have wireless levers, 12 speed cassettes, but all at a lower price point. This new group, which celebrates the 40th anniversary of the introduction of 105, also has some big improvements in braking, and a carbon fiber wheel set which compliments the group nicely. Following is a bullet point list of the new features and improvements:

A frontal look at 105 Di2 levers on a handle bar

Evolved Di2 platform – A completely redesigned Di2 system delivers fast shifting in a wireless
cockpit design.

Most advanced drivetrain – Optimized 12-speed gearing for unmatched efficiency and seamless
shifting.

Refined interface and ergonomics – With the optimal balance of comfort, aerodynamics, and
aesthetics, Shimano 105 provides secure and comfortable ergonomics and a cleaner cockpit
aesthetic.

Enhanced brake system – Improving braking control, the new Shimano 105 brake system offers a
quieter, maintenance-friendly system.

New carbon wheels – Blending aerodynamics, rigidity, weight and cost in a competitive full-carbon, tubeless wheel option.

Image showing a smart phone display showing the Shimano E-Tube Project app.
Riders will be able to access Shimano’s E-Tube Project via smart phone to adjust the new 105 Di2 and more.

The new Di2 also features customizable shifting and adjustments via the Shimano E-Tube Project which is an app for your smart phone. Riders can use the app to adjust shifting speed, how many cogs are shifted per shift, or utilize the Synchronized or Semi-Synchro shifting options. You can also pair the system with most third party cycling computers, including Garmin and Wahoo, to monitor shifting selections and battery life.

The new 105 Di2 Dual Control Levers have been refined with a new lever shape and improved ergonomics in the hood. These refinements include improved button access and better aerodynamics as well. Internally, the Dual Control levers have batteries which can be accessed via a flip top at the peak of the levers just under the hood covers. The 2X12 levers each use two CR1632 wafer batteries to operate the wired derailleurs which run off one internally mounted battery pack. This battery has an indicator located on the back of the rear derailleur and the battery recharging port is located on the rear derailleur as well, making recharging the battery easier for the rider.

The drive train has several features and innovations which are listed in the following bullet point listing provided to us by Shimano in their press release;

The new 105 Di2 crank set

FC-R7100 Crank (Retail $179.99 w/chain rings)

  • HOLLOWTECH II Crank Set
  • 2×12-speed
  • Chainring combinations:
    o 50-34T
    o 52-36T, available at later date

CS-R7100 Cassette (Retail $65.99)

  • 12-speed
  • 11-tooth small cog for optimal efficiency
  • Optimized “Sweet Spot” Gears for pedaling efficiency
  • Compatible with 11-speed freehub bodies
  • 11-34T
  • CS-HG710-12 Cassette (Retail $87.99)
  • 12-speed
  • 11-tooth small cog for optimal efficiency
  • Compatible with 11-speed freehub bodies
  • 11-36T, available at later date
    RD-R7150 Rear Derailleur (Retail $279.99)
  • SHIMANO SHADOW Rear Derailleur
  • Integrated D-FLY connectivity
  • 12-speed Di2 technology
  • Compatible with 11-34 and 11-36T cassettes
    FD-R7150 Front Derailleur (Retail $152.99)
  • 12-speed Di2 technology
  • Fast, precise front shifting
A graphic showing the improved pad to rotor clearance on the new 105 brake calipers.

The brakes on the new 105 group also get upgraded with faster pad contact, 10% more pad to rotor clearance when the brakes are at rest, and a new ICE TECH rotor for quieter performance. Riders should experience improvements in modulation and power with the new 105 level hydraulic calipers. Furthermore; the bleeding procedure has been simplified by not having to remove the caliper from the frame or fork to do the bleeding procedure.

Brakes w/Di2 Dual Control levers and hoses are $404.99 per side and rotors are $45.99 each. (See further below for information on the new ICE TECH rotors)

Detail of a new Shimano RS-710-46-TL rim
The new 105 level carbon wheels will have a subtle graphic treatment.

Rounding out the new introductions, Shimano also announced two new RS710 carbon wheel sets for the new 105 group. These affordable wheel sets will feature tubeless compatibility, 11 and 12 speed compatibility, and share 21mm internal rim widths. The two options differ in their intended use and profile. The RS-710-32-TL is a wheel with a rim that has a 32mm depth and is intended for climbing while its sibling, the RS-710-46-TL is the more aero, 46mm rim depth wheel. Target weights for the wheels are 665 gm front, 839 grams rear for the 32mm deep rims and 719 grams front, 893 grams rear for the 46mm deep rim wheels. Both wheel sets are set to retail for $1049.00 USD.

Comments: Here at Riding Gravel, we are taking a bit of a different view here with regard to this new road group from Shimano. As mentioned in the introduction, we have to wonder what features and innovations seen here in the new 105 Di2 might cross over to a new GRX group.

Graphic showing the 105 rear derailleur charging port and battery life indicator.
105 rear derailleurs have a charging port and battery life indicator built in.

GRX debuted in the Fall of 2019. So, it would stand to reason that GRX is coming due for an upgrade soon. Maybe not next year, but 2024? That would make sense to us looking at Shimano’s history of component upgrade cycles. It is safe to say that GRX is probably going to look different within the next two years.

We think it is safe to say that the upper level of GRX will definitely be 12 speed and should have the wireless levers, like the new 105 shown here does. The big question that we have is will Shimano axe any option for a mechanically shifted drive train under the GRX range?

Obviously, we don’t know the answer to that question yet, but Shimano is showing great confidence in the durability of its new Di2 systems by making 105 electronic. Still, we can see an 11 speed GRX which would replace the 10 speed GRX as the entry-level component group for bicycles ranging in the 1000-2000 dollar price point.

The braking improvements will most likely be seen on any new GRX introduction as well. We like the better pad-to-rotor clearances. That’s going to make traversing muddy roads less of a danger to pad life due to the allowance for grit and grime to pass through the calipers more easily.

The new RT-CL900 ICE TECH Freeza rotors.

The new rotors from Shimano, the RT-CL900 and the RT-CL800 are already being pushed by Shimano as a better rotor for gravel use. The CL900 has a heat dissipating paint treatment, while the CL800 does not. (Retail prices are CL900 – $85.99 and CL800 – $60.99 per rotor) Both are Center Lock, of course.

The new rotors are said to better resist heat deformation under prolonged usage during long descents. This has been achieved with the use of a new alloy arm carrier design. The improvements will allow for quieter and more consistent brake performance, according to Shimano.

We’d expect that all of this will be featured within the new GRX whenever Shimano introduces that upgrade. Related to the brakes, we also expect to see the new pivot placement, only available on the upper end GRX 810 Di2 levers now, to be applied across the board in any new GRX introduction. This new pivot placement will allow riders to brake from the hoods position with less effort. This along with the new features seen in the 105 brakes should make what is already the best brakes for gravel riding even better.

An exploded view of a Shimano 105 12 speed cassette.
The Shimano 105 12 speed cassette.

In the area of gearing, some have taken Shimano to task for not making a drop bar compatible, super-wide range drive train available in the GRX series. Will Shimano answer the call? SRAM has AXS XPLOR which already offers this option.

Shimano has always kept the MTB side quite separate from the road or gravel stuff and we’d expect that trend to continue. However; you might notice that the new 105 will have an 11-36T cassette option, which – in a road group- was unheard of a decade ago. So, we think there is a possibility that Shimano may make an extended range 1X GRX option available.

It probably won’t be quite as wide ranging as a SRAM offering, because Shimano is very focused on shifting quality and durability. If Shimano feels that by offering a wide range cassette in the GRX range compromises on those two area, you can bet you won’t see anything offered. Shimano would rather not have component performance issues at all than to have riders think that they are on par with SRAM’s offerings and have sub-par performance in their view.

That’s our take. What do you think?

Note: Riding Gravel would like to thank Shimano North America for providing us with the information and images used in this post.

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Author: Guitar Ted

Guitar Ted hails from Iowa. Home of over 70,000 miles of gravel and back roads. An inaugural member of the Gravel Cycling Hall of Fame and Co-creator of Trans Iowa in late 2004- Guitar Ted has been at the forefront of the growth of gravel events and riding since then. Creator of Gravel Grinder News in 2008, he produced the premier calendar of gravel and back road events. GT joined forces with Riding Gravel in late 2014.

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