By 
In June 2022, Shimano unveiled its new 7100-series 12-speed 105 Di2 components. At the time, we wondered if 105 was destined to become an electronic-only group (like Ultegra and Dura-Ace) or if Shimano would follow up with a 12-speed mechanical version. Those questions were seemingly answered in published information by KHS for the 2024 Flite 700 (pictured with 11-speed 105 parts) on the brand's website. I have posted screen captures here in case the bike’s page gets pulled down.
Shimano’s 105 Di2 components carry R7170 (STI levers) and R7150 (derailleurs) series numbers. However, the 105 parts on this KHS are listed with R7120 (STI levers) and R7100 (derailleurs). Parts with those model numbers do not exist in the current 12-speed 105 Di2 range or the outgoing 105 11-speed mechanical (R7000) series.
When Shimano mechanical and Di2 components exist in the same series, the mechanical parts have a lower series number. For the previous generation Dura-Ace, the Di2 parts were R9150 and R9170 series, while the mechanical parts were R9120 and R9100. So, history would suggest that the R7120 STI levers are for mechanical shift/hydraulic disc, and the R7100 derailleurs are mechanically actuated.
More From Bicycling
This is noteworthy because Shimano has not publicly acknowledged the existence of a 12-speed mechanical 105 group. When reached for comment about a 12-speed 105 mechanical group, a Shimano press representative said only, “Shimano is constantly in development of new products but does not comment on rumors, innuendo, or speculation about products whether they are in development or not.”
The other Shimano parts on the Flite 700 include the CM-M7100 12 chain, BR-7170 brake calipers (shared with 105 Di2), and CS-HG710 12-speed cassette. For the crank, KHS uses the FC-RS520 “non-series” 2x12 crank, which is less expensive than the R7100 series 105 crank.
A 12-speed mechanical 105 group is very noteworthy. 105 is a popular specification on many mid-range drop bar racing, road, all-road, gravel, and cyclocross bikes. 105 is perhaps the most popular group used on “enthusiast” drop bar bikes. And I’d guess there are more riders on 105-equipped drop bar bikes than any other road group (though Tiagra is also extremely popular).
105's popularity is for good reasons: Not only is it usually a great riding group (the outgoing R7000 11-speed mechanical group is/was stellar), 105 typically has 90 percent (or more) of the features and performance of top-range Dura-Ace for a lot less money.
However, the introduction of 105 Di2 12-speed and the sunsetting of 105 11-speed mechanical (Shimano says they “continue to support” the old 105 group) created a big hole in the middle of Shimano’s parts line. 105 Di2 12-speed costs significantly more than 105 11-speed mechanical and is therefore found on more expensive bikes. Using KHS’s line as an example, a 2022 Flite 750 with 11-speed 105 mechanical sold for $2,900; a 2024 KHS Flite 750 with 12-speed 105 Di2 sells for $4,400.
In its current form, Shimano’s line jumps from 12-speed 105 Di2 to 10-speed Tiagra mechanical. Returning to KHS’s line, the 2022 Flite 700 with Tiagra 10-speed sells for $2,500. This creates a wide gap (from $2,500 to $4,400) in KHS’s drop bar line. And this space typically includes some top-selling models in bicycle manufacturers’ lineups.
A 105 12-speed mechanical group would help plug that hole. I’d also expect Tiagra to get a revision shortly and become an 11-speed group. Perhaps Shimano will rebadge the awesome R7000 105 11-speed mechanical group with the Tiagra name and series numbers, though I doubt that will happen.
If you’re wondering why I’m not using any 2023 KHS models for comparison: The brand does not have any 2023 models. It skips the ‘23 model year, likely due to product shortages. In fact, the 2024 Flite 750 with 105 Di2 12-speed I mentioned above is not expected to land in shops until this September due to Shimano parts availability, or lack thereof.
Remember, Shimano announced its 12-speed 105 Di2 in June 2022. Sometimes it can be up to a year between a product announcement and when bikes with the parts are readily available for sale. Hopefully, Shimano straightens out its component availability before the 12-speed 105 mechanical is officially announced—all indications are that it will be at least a handful of months before it does. Even if Shimano has everything buttoned up, there will probably be some delay between the group’s announcement and bikes with the new 105 mechanical available for purchase.
A gear editor for his entire career, Matt’s journey to becoming a leading cycling tech journalist started in 1995, and he’s been at it ever since; likely riding more cycling equipment than anyone on the planet along the way. Previous to his time with Bicycling, Matt worked in bike shops as a service manager, mechanic, and sales person. Based in Durango, Colorado, he enjoys riding and testing any and all kinds of bikes, so you’re just as likely to see him on a road bike dressed in Lycra at a Tuesday night worlds ride as you are to find him dressed in a full face helmet and pads riding a bike park on an enduro bike. He doesn’t race often, but he’s game for anything; having entered road races, criteriums, trials competitions, dual slalom, downhill races, enduros, stage races, short track, time trials, and gran fondos. Next up on his to-do list: a multi day bikepacking trip, and an e-bike race.
