You could spend a lot of snowy days by the fire reading Shimano patents. Heck, you could spend years. Get cozy, because Shimano recently added to the pile with more patents regarding its wireless shifting system.

It’s a big question mark about when we’ll see Shimano’s wireless shifting system, or if we’ll see it at all. (All signs point to yes.) And of course, we still don’t know what it will look like. These patents give us some clues. But ultimately, a patent does not necessarily reflect what the final product will look like.

Let’s dig into some of the clues we can glean from the latest patents regarding Shimano’s wireless shifting system.

Wireless shifting: Now with wires!

Like FSA’s WE system, it appears Shimano’s wireless shifting system won’t ditch wires altogether. But we already knew that from previous patents Shimano has filed. The system will include fully wireless shifters, it seems. These will work in conjunction with the derailleurs, battery, and junction box. Wireless receivers appear to be integrated into the derailleurs (labeled WC3 on the rear derailleur in FIG. 3). 

Shimano wireless shifting FIG 3
FIG. 3 shows the wireless receiver integrated into the rear derailleur (labeled WC3).

The newest crop of patents regarding Shimano’s wireless shifting system seem to be iterative. That is, Shimano has been dreaming up a lot of different ways to set up the charging and powering system. This is yet another.

In this version, the front and rear derailleurs connect to the main battery. A junction box splits the power from the battery to each derailleur.

But there’s a third wire in FIG.3 that seems a bit mysterious upon first look. That wire, labeled EW, allows the system to charge without having to access the battery directly. That’s useful, since the battery will be tucked away inside the frame or seatpost, as is the case with the current Di2 system.

Instead, the system gets charged via the EW wire. This presumably plugs directly into a wall outlet. It’s possible this could eliminate a separate junction box component, similar to the one found on Di2 systems. That’s where you plug in the Di2 charger, and where you fine-tune the derailleurs. It’s possible future micro-adjustments can be accomplished via the shifters with the wireless system. SRAM’s eTap system works this way.

The wireless shifting mystery

Alternate battery setup
FIG.5 shows an external battery, labeled BT2. This would make a lot of sense for a 1X setup.

Check out FIG.5 and you’ll see an alternate battery setup. The rear derailleur has a battery labeled BT2 that is mounted to the derailleur itself. The same charging cable Shimano uses on the wired system can be used to charge this external battery. in this example, we’re seeing a truly wireless shifting system.

The problem is, there wouldn’t be a way to charge the front derailleur in this example. The solution: Who needs front derailleurs anyway? FIG.5 seems to represent a wireless shifting system ideally suited to 1X drivetrains. Does that mean gravel/road? Or does that mean MTB wireless shifting? indeed, the system could work in any of those scenarios.

Take your keys with you?

Removable wireless receiver
Can you take your wireless receiver with you? FIG. 8 shows a removable wireless shifting receiver.

FIG.8 has another intriguing little detail. The rear derailleur includes a removable wireless communicator, labeled WC5. It’s unclear what purpose this might serve.

My best guess here is that by removing the wireless communicator, you can disable the wireless shifting system altogether. That could be handy if you’re headed into the coffee shop and don’t want anyone to be able to shift your gears should they get it in their heads to steal your ride.

That’s purely a guess, though. It’s possible Shimano has other reasons for this removable communicator on its wireless shifting system. (Got ideas? Post ’em in the comments below!)

Dropper control

Shimano battery
Shimano’s battery has three ports, which means three wires will run to various components of the ‘wireless’ system.

In a separate patent filing, Shimano has also put its mark on a new power supply. This supply can drive power not only to the wireless shifting system, but also to a third component — most likely a dropper post.

Notably, the power supply features a wireless receiver. That means the wireless communicators — the shifters, in other words — will send wireless signals to the battery’s wireless receiver. The battery will then send power and shifting signals to the derailleurs. It’s possible that the same system works for the third component as well (think dropper post or even suspension systems).

Interestingly, the cables can transmit both power and information. FIG. 3 also shows that the system can connect wirelessly to your computer. That’s an important integration for us data nerds.

Wireless shifting diagram
According to FIG.3, the system will be able to communicate with your cycling computer.

Battery life is paramount

It should come as no surprise that Shimano seems to be placing a premium on battery life with its wireless shifting system. Its Di2 system notably has a long battery life, often allowing riders to go weeks or months between charges.

Sticking with the same type of battery and wires running to the derailleurs seems to be a play for reliable, long battery life, thereby setting it apart from some of its competitors.


Patent research assistance provided by Check them out for deeper dives on some of these patents and more.


  1. Bike Rumor: “we don’t know what any of this means”
    Meanwhile: has full ride reviews, got their hands on a preproduction models months ago, has already completed a long term test, and has articles ready to hit send on Sunday March 21st when Shimano goes live with their 100 year celebration site and new product launches…

  2. There is no mystery here! Shimano already said they won’t change anything unless they develop a wireless system that performs better than the current system.

  3. Why’s that important? You’ll already have a fat hydraulic line running from your shifter to your rear wheel. Why would just one small di2 wire make an important difference?

    • Less labor for OEMs to install, less materials to purchase, then manufacture and package and sell, and for retailers to stock.

  4. What Shimano needs to do is develope a complete wireless system with shifting and breaking. It will happen someday.

    • What do you do when your brake runs out of battery? That is a hard pass for me and an instant lawsuit for any company that releases wireless brakes. You already see pro athletes forget to have their team mechanics charge the batteries. Or the batter stops working. Just imagine if that was your brakes and you are mid decent.

  5. SRAM wireless system is easily adaptable to any frame, from what I see, Shimano again is going against the grain / PRO level system with few chosen brands (read very expensive) and not transferable between bikes… Waste of time in my mind…

  6. Existing Di2 components are interchangable between Ultegra and Dura-ace. Therefore, the new Shimano Di2 maybe compatible with older versions to allow a gradual upgrade.

  7. I’m an EE and have been worried that Shimano would go the SRAM e-tap etap path and lose all of the advantages of super long battery life. Wireless levers still have the problem of running hydraulic lines so the idea of simply bolting on levers and being good to go will have to weight for electronic brakes which I don’t see anytime soon.

    Shimano engineers are way ahead here and achieve the advantages of wireless without the disadvantages.

  8. This is flawed logic. Not every bike will be this way so only the shop that exclusively works on DI2 would see any benefit. Same for the manufacture. Plus they would need wires for the rest of the build. This really solves nothing or almost nothing. As already mentioned you still have a brake line so it is not like you could take the bars off completely for traveling or something.

  9. ^This. In terms of shifting performance, wireless groups have nothing over wired groups. For those worried about the extra grams, eTap is heavier than Di2. Battery life? Another win for Di2. Aesthetics? Well, that’s a subjective measure, and given the design “evolution” of modern bikes and their concealment of wires, I don’t see any aesthetic win here. Aerodynamics? See the previous point. There’s likely no difference in aero drag between the two, give or take a gram or two.

    The only real advantage I can see that eTap has over Di2 is that eTap can be more easily adapted to older frames, but I think Shimano is more than willing to cede that small portion of the market to SRAM.

    Oh, I guess eTap is easier to install, but honestly how many buyers are doing their own installation? And for those doing their own installation, it’s a one time thing. It’s not like it’s something that has to be repeated frequently.

  10. The current landscape of hard-to-get bicycles, frames, parts, etc. has seen a huge uptick of frame build-ups, parts swaps and rebuilds in our shop so far this year.

    After completing several of these projects over the past couple months I can say that all current, high-end component groups have their quirks.

    We can all concede that running hydro hoses through frames and handlebars is an equal inconvenience shared across the current offerings.

    I can definitely say that after the brake plumbing is completed, a fully wireless or a fully mechanical shifting system is easier and faster to assemble and adjust than Shimano’s current system of junctions, wires, internal batteries, etc. and if they don’t go fully wireless as Sram has done, there’s no point in changing their current system.

  11. for me it looks like a groupset where the customer can choose between:
    a: easy mounting & clean look = wireless and
    b: long battery life = with powerful central battery.
    very smart from my point of view.

  12. Interesting. I am going to guess Shimano is going to do a multi-step transition to wireless shifting. Or, only their really high end groups get wireless, the others get semi-wireless. In either case, I will not pay for semi-wireless. I think it is dumb. Full wireless as SRAM has done is the way to go. Also, if you look at the ridiculous prices Shimano charges for bits of wire to connect all the parts of Di2, you don’t want to be stuck with that again. They need to look at the simplicity of the SRAM system. All you do is attached the derailleurs to your frame and then adjust them with the levers. Not stupid junction boxes and external controllers needed to adjust things.

    • My two knocks against AXS are that it has 4x batteries and the gearing scheme isn’t very useful. They should get rid of the 10t and use larger chain rings so the most common ratios have straighter chain line and larger cogs.

      I like the consolidation of battery and wiring on this system and I might’ve liked it more if the radio were centralized too, so the F/D could be simpler and smaller. Since the main drivetrain parts will always be fixed in their positions, I don’t see any benefit in making them wireless from each other.

  13. Oh just please make these such that one can charge the battery with some regular USB(-C) charger, so that one doesn’t need yet-another-proprietary-charger for that.

  14. For me the best system would be the one that lets the end user decide. If you took your derailleurs and had a detachable battery (think SRAM AXS) that would provide for clean builds and for those who want 1 x systems such as XC & Gravel. Communication between the shifter and derailleur is wireless. Then for those who want a single more powerful battery running everything like current Di2, you would simply run a wire and have a connector going where the battery would otherwise go. Then Shimano only need to manufacture one model of derailleur (road, gravel & mtb) and it is up to the end user as to how they implement it (individual batteries or a central battery).
    What I really hope for is for Dura-Ace and Ultegra being released together as well as XTR & XT. Then mortals won’t have to wait a year before they can afford it.

COMMENT HERE: (For best results, log in through Wordpress or your social media account. Anonymous/fake email comments may be unapproved or deleted. ALL first-time commenter's posts are held for moderation. Check our Comment Policy for full details.)

This site uses Akismet to reduce spam. Learn how your comment data is processed.