Shimano 105 transformed with Di2, 12-Speed and £$£$£$£$£$

Shimano 105 Di2 12-Speed R71

Shimano 105 Groupset gets 12-Speed, Di2 Upgrade

This is a very significant upgrade for the entry-level, performance groupset from Shimano which puts its technology in sync with the higher-end Ultegra equivalent and pro-level Dura-Ace groupset.

There are several changes but the two headline moves are support for 12-Speed rear cassettes and the move to electronic shifting with semi-wireless Di2.

It’s a BIG update and the BIG update comes at about twice the cost of the previous version.

Latest-gen Di2

The 105-level shifting becomes electronic for the first time at this level. But this requires every component to be completely new to 105.

  • Both derailleurs are wired to a battery which you normally have in the seat post
  • The battery is charged via a port on the rear derailleur
  • Derailleurs communicate to the shifters wirelessly
  • The shifters have coin cell batteries to power them and no wires whatsoever, giving a clean cockpit.
  • You change gear with a ‘button’ that’s built into the main shifter…sounds weird but works well.
  • Hoods are ergonomically redesigned but do NOT have a button on top to wirelessly control your Garmin Edge or Wahoo head unit. (that’s different from Ultegra/Dura-Ace)
  • Di2 offers wide-ranging electronic customisation options
    • Special shift modes to control how the front and rear derailleurs work together. You can control both with one shifter or have intelligent rear gear selection when you shift the front derailleur.
    • Speed and certainty of shifting are configurable
    • Button and lever actions are fully configurable
    • Battery and gear status information is broadcast to your head unit
    • The E-Tube app configures everything and offers firmware updates over the air


It’s like 11-speed but with one more.

Many wheels that currently use 11-speed cassettes will take a 12-speed cassette. Check first!

  • Front chainrings: 50×34 and 52×36
  • Rear cassettes: 11-34 (11-36 to follow)

Eagle-eyed readers will spot the possibility of a super-spinny 34 (front) and 36 (rear) gear combination that gets anyone up the Tourmalet. This is achieved with one cage size (long).

Carbon Wheels

The new C32 carbon wheelset has a 32mm rim depth and is suitable for climbing whereas the deeper, C46 is 46mm and is more of an aero-all-rounder. Weight and rigidity will not be quite as good as the C36 and C50 equivalents for Dura-Ace/Ultegra.

The front weighs 719g and the rear 893g and they come as 21mm Tubeless (TL).


Braking is said to be ‘better’ but other improvements include easier bleeding of the hydraulic system and a wider pad clearance. Presumably, the latter will reduce noise due to misalignment or debris.

Currently, only disc brakes are listed by Shimano. It’s probable that cabled rim brakes will not be supported at all by shifters, calipers and wheels.

Shimano 105 R7100 Product Codes & Pricing

Components for the new Di2-enabled 105 system start with R71




What’s Missing?

There is no mention of an R7100p power meter option. Ultegra only recently received an option for this so it’s possible that R7100 never will. 3rd party power meter manufacturers like Stages and 4iiii will provide compatibility in due course.

Cabled rim-braking systems seem to have gone the way of the dinosaur.



Newer generations of groupsets are genuinely superior to previous iterations. They are typically lighter, faster and perform better in most respects. However, components are becoming technologically and mechanically more complex in order to add value to the product offering…in YOUR terms that means it costs you more but you might be happier with the superior kit; at least until it breaks and an extensive component replacement looms.

Prices are steep but R7100 will be focused on new bikes and you can bet your bottom dollar that Trek, Cervelo, Specialized, Giant and Co will get Shimano components considerably more cheaply than you and I. So there will be ‘deals’ when you get a new bike. That said 105 is broadly half the price of Dura-Ace, so it’s a ‘bargain’ in that sense.

I love Di2 and have done so in earlier iterations of Shimano groupsets. The main thing that excites me with the latest generation is the removal of cabling and a cleaner-looking cockpit.

105 is a great option for nearly all riders but the best performance riders will always want lighter, more rigid and more aero wheels plus lighter components that support a wider range of gearing options.



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