At last! Shimano unveils 12-speed mechanical 105 R7100 groupset to sit alongside existing Di2

Shimano has launched a new version of its 12-speed 105 R7100 groupset, adding mechanical shifting as an option alongside the Di2 (electronic) components that were introduced last year. The new Shimano 105 R7100 Mechanical 12-speed groupset, which is compatible only with hydraulic disc brakes, is considerably cheaper than the electronic alternative – by nearly £700, costing £987 in total. At the same time, Shimano has also introduced a 12-speed mechanical option in its GRX gravel groupset lineup.

> Check out all the news on Shimano GRX Mechanical 12-Speed Components 

Here are a few bullet points to get you up to speed:

• Third-tier Shimano 105 R7100 groupset that was Di2-only is now available with mechanical shifting.
• This means Shimano is offering 12-speed mechanical shifting for the first time on the road.
• New groupset is compatible exclusively with hydraulic disc brakes.
• Shimano is also introducing a 12-speed mechanical option in its GRX gravel groupset lineup.

Shimano 105 Mechanical 12-speed has been the worst-kept secret in the bike industry for, ooh, about three weeks, since the launch of the Specialized Tarmac SL8.  The components were even accidentally displayed at Eurobike before Bianchi unintentionally confirmed that a launch was imminent a couple of weeks ago. 

> Shimano 105 12-speed mechanical groupset breaks cover 

Although Shimano 105 R7100 Di2 has been very well received, many riders were disappointed last year when the Japanese giant's everyman lineup became Di2 and disc brake-only. It also left a gaping hole in the middle of Shimano's range between 12-speed and electronic 105 and 10-speed and mechanical Tiagra.

> Check out our Shimano 105 R7100 Di2 groupset review

Shimano has now officially announced what has long been suspected – that there’s to be a version with mechanical (cable-operated) shifting, although rim brakes remain off the menu. Shimano 105 Mechanical 12-speed shares many components with the existing Di2 version but there are, of course, new shifters and derailleurs.

> Your complete guide to Shimano’s GRX gravel groupset

Shimano says, “With the introduction of the 105 R7100 Mechanical 12-speed groupset, Shimano brings the pure joy of self-powered adventure to the massive community of cycling enthusiasts looking for reliable, easy-to-maintain componentry at an affordable price.”

Of course, “affordable” is a relative term, especially with pretty much everything in the cycling world – and elsewhere – having gone up in price massively over the past couple of years. It’s certainly considerably cheaper than the electronic version of 105.

“The new, lightweight Shimano 105 Mechanical groupset offers premium mechanical shifting, which means riders can capture that natural riding feeling without worrying about battery levels – while still enjoying the comfort and range of a premium 12-speed groupset,” says Shimano.

Like the previous 11-speed option, the new 105 Mechanical 12-speed RD-R7100 rear derailleur uses Shimano’s Shadow RD technology, meaning that it doesn’t extend as far outboard of the bike as a more conventional design. This is intended to reduce the possibility of damage and, Shimano says, means that the derailleur doesn’t hit the chainstay in rough riding conditions.

Also like the previous generation, the FD-R7100 front derailleur features what Shimano describes as a toggle-link construction with an integrated cable tensioner.

“This means riders can rely on hassle-free shifting, whether going up to the larger chainring or dropping down to the small one,” says Shimano.

To be fair, that’s exactly what you’d expect from any front derailleur, isn’t it?

The biggest difference, apart from the change from 11-speed to 12-speed, is the increased gear range. Whereas the 11-speed Shimano 105 medium cage rear derailleur could handle a cassette with a maximum sprocket size (at least officially) of 34T, the 105 mechanical 12-speed RD-R7100 rear derailleur, like a 105 Di2 setup, can work with an 11-36T cassette.

“With the jump to 12-speed, Shimano 105 R7100 Mechanical delivers the high and low gearing that riders want, along with an intelligent progression of gear steps in between,” says Shimano.

“This is the result of optimised drivetrain components, including 11-34T and 11-36T cassette options, while the FC-R7100 Hollowtech II 12-speed cranksets have 50-34T and 52-36T chainring options.

“Using 50-34T chainrings with an 11-34T, or even an 11-36T cassette means riders can climb any mountain while keeping their cadence efficient and manageable up those long, steady climbs. Additionally, Shimano 105 Mechanical’s semi-compact 52-36T setup will reduce the chance of spinning out mid-descent or when sprinting on the flats.”

These are the cranksets – or chainsets,  if you prefer – that were already introduced for Shimano 105 Di2. The 53-39T option that you had with 11-speed 105 has gone, as it has from Shimano’s higher level Dura-Ace and Ultegra lineups.

The new 105 Mechanical shift/brake levers are a slightly different shape from the existing ST-R7170 Di2 Dual Control Levers. The hood is more rounded, for example, and there’s a more pronounced bump in the brake lever – as with the previous generation 11-speed Shimano 105.

“Designed to fit any hand size and shape, the ST-R7120 Shift/Brake levers provide a relaxed shifting experience with the next-generation ergonomic mechanical shift levers, ensuring more comfort and control,” says Shimano.

“Thanks to a lighter, smoother lever action and expanded braking control area, the reach – the distance from handlebar to lever – is also reduced.”

As previously, the cables and hoses are integrated rather than exposed. Shimano says that braking is optimised for use with its existing 105 BR-7170 callipers which offer 10% more brake rotor clearance than previous designs. The idea is to reduce the chances of pad/rotor rub when you’re not braking. As mentioned earlier, Shimano 105 Mechanical is compatible only with hydraulic disc brakes – there’s no rim brake or cable-operated disc brake option.

Shimano 105 R7100 Mechanical 12-speed components

Here are the various component details. The descriptions are in Shimano’s own words.

RD-R7100 Rear Derailleur £59.99
• Shimano Shadow RD
• Direct mount attachment
• Super low profile, single tension construction

FD-R7100 Front Derailleur £41.99-£44.99
• Fast, precise front shifting

ST-R7120 Hydraulic Disc Brake Set (calliper and lever) £279.99 per side
• Dual control levers
• New blade shape gives a shorter lever access curve
• Refined ergonomics and shaping create a new lever position
• Each shifter is available without a brake calliper, priced at £179.99

FC-R7100 Crankset £159.99
• HollowTech II Crankset
• 2 x 12-speed
• Chainring combinations: 50-34T and 52-36T
• Crankarm lengths: 160mm, 165mm, 170mm, 172.5, 175mm

CS-R7101-12 Cassette £69.99
• Hyperglide 12-speed
• 11-tooth small cog for optimal efficiency
• Compatible with 11-speed freehub bodies
• Cassette combinations: 11-34T and 11-36T (CS-HG710-12, £84.99)

SM-RT70 Disc Brake Rotor £29.99 each

CN-M7100 Chain £34.99

How does the price compare with Shimano 105 Di2?

Here are the prices of the various Shimano 105 R7100 Mechanical 12-speed groupset components compared with their Shimano 105 R7100 Di2 12-speed equivalents (many of the components are the same):

You can see that the Shimano 105 R7100 Mechanical 12-speed groupset is nearly £700 cheaper than Shimano 105 R7100 Di2 12-speed.

How does the weight compare with Shimano 105 Di2?

Here are the official weights for Shimano 105 R7100 Mechanical 12-speed components along with Shimano 105 R7100 Di2 12-speed and SRAM Rival eTap AXS equivalents. We've included Rival because, like 105, it's a third-tier groupset, sitting underneath SRAM Red and Force.

We're not really comparing like with like here in that two of these groupsets are electronic while one is mechanical. Plus, it's impossible to have uniformity between Shimano and SRAM because of different chainring sizes, cassette ranges, and so on, so take these figures as an approximation only.

Shimano says, then, that R7100 Mechanical 12-speed is heavier than 105 R7100 Di2 12-speed by 75g.

Bikes available with Shimano 105 R7100 Mechanical 12-speed

We’ve asked key bike brands whether they’re immediately announcing bikes equipped with Shimano 105 R7100 Mechanical 12-speed. This is the info we've got back so far...

Merida says it will offer the following models:

Scultura Endurance 4000
Scultura Endurance 400
Scultura 4000
Scultura 400
Reacto 4000

We don’t yet have prices on these.

Ribble will immediately offer the following models:

CGR Ti, £2,899 
CGR SL, £2,699 
Endurance SL Disc, £2,199 
Endurance Ti Disc, £2,799 
Endurance SL e, £3,399 

Orbea is announcing these models:

Orca M30, £2,699
Orca M35, 3,899

Bianchi has these already announced models, although it didn’t previously confirm that they were equipped with new Shimano 105 R7100 Mechanical 12-speed components:

Oltre Race, €3,399
Sprint, €2,549

Giant says that it will have 12 Shimano 105 12-speed Mechanical and GRX 12-speed Mechanical bikes arriving shortly, although we don’t yet have details on the models.

This information is by no means exhaustive. Nearly all big bike brands will have bikes equipped with Shimano 105 R7100 Mechanical 12-speed components, if not immediately then within the next few weeks.