There have been predictions, rumours, speculation and an unconfirmed Instagram video leaked by Remco Evenepoel, but now US patents filed by Shimano seem to confirm that the new Dura-Ace groupset will not only be 12 speed and wireless, but it could also use a piezoelectric element in the shifters instead of batteries.
The patent application, which was filed on July 22 this year and discovered by mechanical engineer Alan Coté for Cyclingtips, reads: “The electric-energy generation element generates the electric energy using pressure and/or vibration… caused by a movement of at least one of the brake operating member, the additional operating member, and the button element. Examples of [this] electric-energy generation element include a piezoelectric element.”
Piezoelectric effect works by applying mechanical force to certain materials, such as crystals and ceramics. Under stress, the crystal produces an electrical charge – which would be used to send a signal to the derailleurs. Trigger-operated gas hob lighters and ‘electronic’ cigarette lighters are examples of piezoelectricity in action.
An alternative version of the shifter in the patent describes the use of a more traditional coin-cell battery.
As for the brakes, the shifter descriptions in the document include both the mechanical cable-operated and hydraulic types.
Derailleurs: shared central battery?
Dura-Ace’s new derailleurs will include wireless receivers and in one of the embodiments in the patent application will both be operated by a single battery: “The second battery can be integral with the first battery and provided as one battery,” reads the patent. As with the shifters, however, there’s an alternative version that places a battery in each derailleur.
12-speed cassette: 10-48t
The details of the cassette are more difficult to interpret from the patent application. Twelve sprockets can be counted, and it seems likely Shimano will include a 10t sprocket, as in the drawing, and a 48t sprocket is also pictured, but clearly there will be various ratios available. Hub compatibility remains an unknown.
As was widely predicted, the new Dura-Ace seems set to be electronic only. The patent application documents don’t give any clue as to what it will be named, but if Shimano follows its current numbering system it will be designated Dura-Ace 9200.
Campagnolo this year launched the 13-speed Ekar gravel groupset, while the Italian firm introduced 12-speed to its road groupsets in 2019. SRAM eTap AXS, which was launched in 2019, is the second generation of its wireless technology.
However, Shimano has remained quiet, with the new Dura-Ace groupset rumoured to be tied to the brand’s 100 year anniversary, in 2021. No details have been officially revealed, and by filing applications simultaneously for different ’embodiments’ of its components, Shimano could keep us guessing right up until new the Dura-Ace is unveiled next season.