This pending Shimano patent from last year for a “Derailleur for human-powered vehicle” illustrates an all-new electronic bicycle derailleur design with its own built-in rechargeable battery, and the ability to shift across 13 cogs. Yes, this is a sneak peek at fully wireless Shimano Di2 13-speed drivetrain, with a removable battery.
And control systems tied in with those removable batteries also hint at electronically-controlled suspension AND braking…
Fully-wireless next-gen Shimano Di2 drivetrain patent
In classic patent application legalese speak, this is 28,000 words and 61 diagrams of Shimano describing how a battery could exist on a derailleur in a unique way. In fact, there are 13 or 14 different embodiments (separate design examples) of how this concept could be achieved in a rear derailleur.
Shimano go around in circles to describe what is unique as locating the battery in “a preferred position while maintaining mobility of a connecting assembly”. The gist of it seems to be, that Shimano thinks they have a better place to put their battery on a derailleur’s parallelogram links (inner or outer) for improved performance (Fig. 14), without restricting the movement of the derailleur’s linkage or cage itself.
It’s pretty common, but interesting nonetheless, the Shimano wireless electronic derailleur patent application cites three previous patents. First, an early battery-powered pre-Campagnolo Wireless derailleur patent from six years back. Then, one of Shimano’s own recent Di2 patents. And finally, a still pending SRAM AXS T-Type wireless derailleur patent filed four years ago.
Semi-modular removable batteries
Of note, both front & rear derailleurs appear to have differently shaped/sized batteries (which I believe is necessary to get around a SRAM AXS patent). But Shimano designed the proposed smaller Di2 front derailleur battery (Fig. 5) so you could potentially attach it to a rear derailleur in the case of a dead rear derailleur battery (Fig. 7) while riding. That is a limp home mode that would let you get a few more rear shifts. On the other hand, the larger rear battery could not fit into the front derailleur, so if you drain the front battery, you’ll be stuck on one of the front rings.
In the face of SRAM AXS patents, this is a really big deal!
Also noteworthy, a proposed Shimano multi-charger (Fig. 8) shows the possibility to charge 2 large & 2 small batteries at a time, supporting the idea that more electronically controlled components could be combined in a new wireless Di2 ecosystem. And a separate single battery charger (Fig. 54) that clearly illustrates the smaller battery fitting in the footprint of the larger battery.
Wait, electronic-controlled suspension and electric brakes, too!
A further block diagram specifically mentions electric suspension control, an electronically-actuated dropper seatpost, and even… electric brakes! Yep, dig deep in the patent-speak and we find this: “The second component 24 includes another of the following components: the electric adjustable seat post, the electric front suspension, the electric rear suspension, the electric front brake, the electric rear brake, the electric shift lever, the electric brake lever, the electric front derailleur 30 and the electric rear derailleur 32.”
Wow.
It’s not the first time we’ve heard chatter of electric suspension or electric brake control from Shimano. But do you think they are seriously considering that now?
Road or gravel bike derailleur with a clutch?
The overall shape of the derailleur most used in the patent drawings looks more Dura-Ace than GRX, but there’s clear reference to a low-profile damping system (Fig. 9, #58) between the derailleur body and cage. Plus, a small adjustment screw to dial in clutch tension. But no simple lever to completely disengage it as far as I can see. But there are two notes to a damping electrical cable and even a hydraulically-damped clutch option.
Plus, there’s also a more basic MTB-shaped derailleur (Fig. 29) that shows both the internal battery in the parallelogram and the clutch.
What about this Shimano Di2 patent’s 13-speeds?
The focus of this Shimano Di2 patent application is surely on the wireless aspect and removable battery configuration. But we certainly are not going to skip over the fact that Shimano chose to illustrate their new Di2 concept with a 13-speed cassette (Fig. 10). The cog sizes certainly don’t look to scale (unless we are talking about at 32-53T cluster). But there are undeniably 13 gear there. And with all the talk of a front derailleur, this could be a first 2×13 road bike groupset.
They could have easily drawn 11 or 12 cogs, but decided to show 13!
Now, we just wait and see.
