Jim’s Tech Talk
By Jim Langley
Possibly timed to coincide with the start of the Tour de France, Shimano announced recently that they did what they said they would and have now made their former entry-level group 105 into a brand new electric group with their Di2 technology, the 105 R7100. Of note, it’s now their least expensive electric group.
I said “their former entry-level group,” because 105 R7100 won’t be seen as entry-level anymore with the price tag of $1,890. Consider that you can currently buy the latest mechanical 105 groupset for about $700. The huge price difference will mean that complete bikes with the electrified 105 will start at the low $3,000s, which again is hardly entry-level pricing.
Also changed is that there’s no rim brake option. If you want the new 105, you’ll need a bike ready for disc brakes. And the new group is 12-speed not 11 and there’s an 11-36 cassette (previously it maxed out at 34). The available cranksets are 53/36 and 50/34.
Shimano calls the group “wireless,” however in the fine print they use “semi-wireless.” Problem is there are still wires so it’s not actually wireless. If you want true wireless, go with SRAM’s eTap groups.
What’s the big deal about genuine wireless? For anyone who works on bikes, routing wires can be a huge hassle whereas wireless setup is as simple as pairing the levers to the derailleurs and installing the parts, no wire routing needed. Also, exposed wires are a potential failure point. Simply having someone tangle their bike up with yours could result in a non-shifting bike should they sever your Di2 wire moving their bike. Plus, hidden wires are failure points, too. A common Di2 assembly glitch is not fully connecting a wire.
Weird decision or great decision?
I’d like to hear what you think, but the move to drop all mechanical groups still strikes me as weird. I get the feeling even Shimano might feel this way. Watch their video about the new Di2 105 here. Notice the pains they take to sell the amazingly quiet and smooth shifts of Di2. Listen to how they suggest that mechanical shifting is difficult.
I’ve been riding Di2 since it came out and while I do love the shifting, when I go back to cable shifting I don’t feel like I’m struggling in any way to shift. I find it hard to accept that Shimano really believes mechanical shifting is bad.
Here’s the video:
The problems I have with Di2 as the only option
Here are 4 reasons I think that it’s a mistake for Shimano to only offer electric shifting road groups:
1. The high prices. Since e-groups showed up I’ve been trying to understand why they cost so much. I appreciate that the battery has to add cost, but it’s a tiny and seemingly simple one. Also and probably a bigger question, other electronics always drop in price after they’re established. Why is it that all that e-groups seem to do is stay expensive? The little motors and controllers can’t be all that expensive, can they?
2. Obsolescence. When my Dura-Ace Di2 front derailleur stopped shifting I reached out to Shimano and learned that the only fix was to replace it. When I asked if I could order a replacement I learned that they’re not made anymore. Why? Because the new derailleur isn’t compatible with the old. Just like the way computers and cellphones become useless when technology pulls the rug out from under your feet, that’s what happened with my Di2 derailleur.
3. Electric derailleurs wear out. Mechanical derailleurs last decades, which is what you expect from high-priced top-quality things. My Di2 derailleur wore out in years. If an electric drivetrain is going to wear out that fast, I would hope replacement parts would be readily available and cheap. But they’re not. Here’s the whole story of my failed derailleur:
4. Di2 has a basic operational problem or issue that mechanical shifting does not. It’s something that both SRAM and Campagnolo realized and addressed/avoided in designing their e-groups. The problem is that there are two small buttons (or “paddles” or “levers” if you prefer) on each Shimano shifter. These buttons are inline and as close together as possible. This means that you have to choose and push the correct button to hit the gear you want. It’s easy to mis-shift by unintentionally pressing the wrong button. It gets worse when wearing winter gloves. On Shimano STI mechanical shifters, there are two levers, too, but they’re large and different shapes so you’re far less likely to mis-shift.
Summing up, the thing that troubles me the most about this development is the eagerness to drop mechanical groupsets. The magnificent thing about bicycles is how easy they are to fix by almost anyone and with really basic tools. Yes some specialized tools are needed for some tasks but those aren’t that hard to come by or expensive.
Batteries, applications, chargers, motors, controllers, wires and wireless tech is anything but user-friendly when things stop working. The Shimano and SRAM e-groups I’ve used and worked on have been reliable and worked well when properly set-up. But, when things really go wrong as with my failed derailleur, there’s no fixing it. In fact it wasn’t even made to be fixed.
Maybe the big companies can change that by making their electric components repairable. Even better would be if they were upgradeable to work with future electric, communication and software technologies.
Yet, a company as powerful as Apple can’t even make computers that aren’t obsolete in a few years. Maybe Shimano wants to be Apple, or like Apple? I can see how that might be appealing. That unfortunate pun aside, I have a hard time believing the bicycle industry can do better than Apple. Which is sad because Shimano was really, really good at making mechanical stuff.
I’ve had my say. What’s your take on this development?
I actually received a somewhat related comment from frequent contributor Kenneth Pierce. I’ll share what he wrote to start the conversation – he touches on reverse compatibility:
“Why are gears getting so low that us flatlanders can’t enjoy the ride? I just bought a new high end race bike and the rear cassette is an 11-36!!!! What is happening? My mountain bike gears aren’t even that low. And I bet the pros don’t use gears that low, and I bet the big S makes higher gearing for them. Why not pass it on to us?
And to top it off Shimano only makes two cassettes for their 12 speed, 11-34 and 11-36, arrrrr! I still use a 53×12 and rarely get into the lowest three cogs. And if I do I’m still in my big ring, the old fashioned 53T. I tried putting an 11-23 on my 11 speed Di2 but it won’t work. Frustrating. Thanks for letting me vent.”
Here are some links to more details on Shimano’s Di2 105:
Shimano’s overview: https://road.shimano.com/us/105di2/#components
Shimano’s page with more details: https://bike.shimano.com/en-US/product/component/shimano105.html
BikeRadar’s extensive report: https://www.bikeradar.com/news/shimano-105-di2-r7150/
GCN’s sponsored video – lots of riding shots: https://youtu.be/juGiU45tEAc
Jim Langley is RBR’s Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter. Jim’s cycling streak ended in February 2022 with a total of 10,269 consecutive daily rides (28 years, 1 month and 11 days of never missing a ride). Click to read Jim’s full bio.