When Shimano launched its latest 12-speed Dura-Ace and Ultegra groups in 2021, it announced the end of mechanical shifting for these premium product levels—leaving its excellent 105 groupsets to carry the torch of mechanical shifting. In 2022, we got the long-rumored 12-speed 105 Di2, but Shimano was still rather cagy about whether there would be a 12-speed mechanical equivalent.
Fortunately for fans of not having to charge their drivetrains, Shimano officially unveiled a 12-speed 105 mechanical group in 2023 with the numerical designation of 105 R7100. In many ways, Shimano’s most premium mechanical groupset shares all of its big details with 105 Di2. The groups share many parts, including chain, cassettes, cranks, and brake calipers.
Pros
- Great shift quality
- Excellent lever ergonomics
- Solid brake performance
- Lots of crank length options
Cons
- Stepped reach adjustment could bother riders looking for more precise adjustment
Riders can still choose between an 11-34T or an 11-36T cassette, which feature simplified versions of the downshift ramps, compared to Ultegra and Dura-Ace cassettes. The chain is the M7100 model shared with 105 Di2 and the SLX mountain bike group. Cranks are carried over from the 105 Di2 groupset and are available in lengths of 160, 165, 170, 172.5, and 175 mm. Riders can opt for chainrings in either 50/34 or 52/36T.
The 105 calipers are carried over from 105 Di2 and share the same revised design that trickles down from Dura-Ace and Ultegra. They provide an extra 10% more pad clearance compared to older 10—and 11-speed groups. Shimano matches the calipers to the SM-RT70 disc rotors, which are center-lock and feature Shimano’s IceTech cooling technology. However, pretty much any Shimano disc brake rotor will work.
Shimano revised the shifters and derailleurs, but you’d be hard-pressed to tell much difference between the 11-speed and 12-speed versions. Shimano also significantly consolidated the options of the 12-speed 105 from the 11-speed version. There is only one option for both derailers, there is no longer a rim brake option for the shifters, and the shorter reach version has also been discontinued. Instead, the new shifters feature a shape that, according to Shimano, is in the middle of the two previous options and features a revised brake lever that allows for a shorter reach.
Cross Compatability and Upgradability
The new R7100 groupset is cross-compatible with Shimano’s 12-speed chains, cassettes, and cranks. This is good news for riders who love mechanical shifting and prefer higher-end options for mechanical groups. These riders could buy a bike with new 105 and upgrade the crank, cassette, chain, and rotors to Dura-Ace or Ultegra level. Or they could piece together a 105 mechanical groupset with upgraded parts for a frame-up build.
This would improve the shifting performance as Shimano’s higher-tier cassettes and chains feature more complicated ramping. It would also drop considerable weight and give riders options for more aggressive gear ratios. For more forgiving gear ratios, riders can mix in parts from Shimano’s 12-speed mechanical GRX group, which is cross-compatible.
Shimano maintains 12-speed cassette compatibility for HG freehub bodies, so if you have some 11-speed disc brake Shimano wheels, the new 12-speed cassette will fit fine. Otherwise, backward compatibility is an official no-go with 12-speed 105. Unofficially, you can run an 11-speed crank and chainrings, but Shimano will greatly frown on this.
Price and Weight
Claimed weight for the new groupset is 3,026 grams. This is based on a 172.5 mm long crank with 50/34T chainrings, an 11-34T cassette, and 160 mm brake rotors. This is within a few grams of 105 R7000. By comparison, 105 Di2 is 2,991 g, Ultegra Di2 is 2,690 g, and Dura-Ace Di2 is 2,437 g.
Those weights are good when you consider the pricing. R7100 retails for $1,005 (down from $1,110 for the 11-speed R7000), $850 cheaper than 105 Di2, or about a quarter of the price of a Dura-Ace groupset.
Ride Impressions
The shifting on R7100 is as crisp and precise as ever. I can’t say if it’s as good as Dura-Ace or Ultegra since there is no Dura-Ace or Ultegra to compare it to. But it’s excellent and on par with the 11-speed Dura-Ace and Ultegra groups. The shift action at the lever is light and pleasant, but with just the right amount of weight and feedback, you never feel unsure of what the drivetrain is doing.
Shifting under power is as good as it gets with a mechanical groupset. You can shift the rear derailleur at will. While the front takes more care, I never found it to hold me back when riding normally. Only if I tried to shift it poorly on purpose did it struggle.
The shape of the hoods is largely carried over from the 11-speed version. The rubber hood covers are grippy and comfortable. While I don’t love the looks of these levers, I constantly marveled at just how comfy they were when riding.
The new curvier brake lever allowed my fingers to rest on the brake levers more comfortably. It’s a subtle but noticeable change. To accommodate various hand sizes, there is a reach adjustment built into the shifters that can be adjusted using a 2 mm hex key.
Brake performance is solid but not entirely up to the high bar set by Dura-Ace and Ultegra. This is mainly because 105 levers do not feature Servo Wave Action, which improves modulation on the Dura-Ace and Ultegra levers. Still, there is plenty of power, and unless you’re constantly switching between 105 and Dura-Ace, you won't notice the drop-off in modulation.
Competition and Final Thoughts
R7100 has no direct competition in the current market. SRAM’s current road groups are all eTap AXS (electronic). SRAM’s only mechanical groupset offering is Apex XPLR, which is more gravel-focused and only available in a 1x setup. Campagnolo still offers a range of mechanical groups, starting with Centaur (which is rim-brake only). If you want hydraulic disc brakes combined with mechanical shifting, you'll need to go with Chorus, which is priced closer to 105 Di2. This is to say that riders have minimal options for mid to high-level mechanical shifting in 2025.
Part of this likely comes from overall consumer trends and what sells at a given price point. The new 105 groupset is excellent and continues the long tradition of 105 being the groupset of (collegiate racing) champions. But I’m not convinced that I would want to run a mechanical shifting groupset on a modern bike with through-the-headset cable routing. Most of these systems are designed with just two hydraulic lines in mind, and cramming an additional pair of housings through that space is a recipe for a reduced lifespan for those cables. Combine that with the increased cost of maintenance for bikes like this, and what you get is riders shopping at the mid to low end of the market are hit with higher and more frequent repair bills.
Despite all this, I’m glad Shimano is keeping its mechanical 105 groupset going. While it doesn’t carry the premium cache of Dura-Ace or Ultegra, it’s one of the best shifting mechanical groupsets I’ve had the pleasure of testing.
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Test Editor Dan Chabanov got his start in cycling as a New York City bike messenger but quickly found his way into road and cyclocross racing, competing in professional cyclocross races from 2009 to 2019 and winning a Master’s National Championship title in 2018. Prior to joining Bicycling in 2021, Dan worked as part of the race organization for the Red Hook Crit, as a coach with EnduranceWERX, as well as a freelance writer and photographer.
