New patents reveal 12-speed Dura-Ace will be semi-wireless

Most conclusive US patent application yet shows front and rear mechs connected to a single junction box and battery

Dura-Ace shifter
(Image credit: US Patent and Trademark Office)

The big question over whether the new flagship Shimano Dura-Ace groupset will follow SRAM eTap in being wireless appears one step closer to being answered.

It will be semi-wireless, according to new US patent applications uncovered by road.cc.

Previous patent applications had featured multiple embodiments, including one where the shifters were powered by piezoelectricity, technology borrowed from ‘electronic’ cigarette lighters.

Shimano Dura-Ace

(Image credit: US Patent and Trademark Office)

But this latest one clearly shows coin-cell batteries and the way their compartments are integrated into the hoods – meaning the shifters themselves will be wireless.

Meanwhile, another wiring diagram shows both the front derailleur and the rear derailleur connected by wires to a Di2 battery, which looks identical to the current BT-DN110-A Di2 battery that mounts internally in the seatpost.

Shimano Dura-Ace

(Image credit: US Patent and Trademark Office)

Accompanying wording runs: “The operating device 10 is wirelessly connected to the electric component BC2 and the additional electric component BC3. However, the operating device 10 is connected to the electric component BC2 and the additional electric component BC3 via an electrical control cable.

"In this embodiment the electric component BC2 includes a gear shifting device such as a derailleur.

"Operating device 10 is a right-hand side operating/control device configured to be operated by the rider’s right hand. [Similar] structures can be applied to a left-hand side operating device."

It also seems certain that the new groupset will be 12 speed: early drawings have shown 12 sprockets.

What isn’t yet certain is when we’ll see new Dura-Ace in the flesh. There was earlier speculation that it would be unveiled to coincide with Shimano’s 100th anniversary in March, but that was celebrated instead with the launch of a limited-edition commemorative book.

It’s also unusual that we haven’t spotted it being race-tested on any Shimano-sponsored WorldTour team bikes yet.

Catch up with everything we know so far about the new Shimano Dura-Ace here.