More images of Shimano’s next-generation Dura-Ace Di2 R9300 groupset have surfaced on the Weight Weenies forum.
The images appear to be leaked from US government filings related to the groupset’s wireless communications protocols, and potentially confirm which parts will operate wirelessly – and which will not.
They also offer a closer look at Shimano's new direct-mount cranks and integrated power meter.
This latest leak follows our sneak peak at the new groupset at La Vuelta late last month, and adds weight to our suspicions that the groupset we saw there is close to the finished article.
Semi-wireless looks increasingly likely
The main conclusion we can draw from this set of leaked images is Dura-Ace Di2 R9300 will very likely be semi-wireless.
Aside from the absence of any images of a wireless front derailleur module, the rear derailleur module shown features both a wire port and a charging port – both of which are almost identical to those on the current version, Dura-Ace Di2 R9200.
This indicates strongly that Dura-Ace Di2 R9300 will continue with a semi-wireless configuration, with the rear derailleur and front derailleur (where present) wired to a single battery housed within a bike frame. In this system, the rear derailleur acts as the ‘brain’ of the system, communicating wirelessly with the shifters.
Note I say ‘almost identical’, though, because it appears Shimano has modified the charging port on the new rear derailleur module.
While the current charger port also uses a four-pin design, the pins are arranged in a horizontal line, rather than grouped into a square as in the leaked images.
Hopefully this change is required due to improvements with the internal battery – perhaps a higher-capacity or faster-charging model, for example – rather than a simple change just to kill off backwards compatibility.
Although it’s not clear whether the filenames were amended by the person who uploaded the images to the Weight Weenies forum, they also appear to confirm the part name will be RD-R9350.
Shifters mostly unchanged
Another area where it seems there’ll be little to no change is with the main shifter paddles.
Shimano has stuck doggedly to its shifter logic for Di2 ever since its inception back in 2009, with Dura-Ace Di2 7900 – with two main buttons on the side of each brake lever.
Although now configurable, the typical shifter logic is that the two right-hand buttons control the rear derailleur (shifting up and down the cassette), while the two left-hand buttons control a front derailleur in the same manner.
This much was already a fairly safe bet based on what we saw of the new shifters at La Vuelta, but it’s nevertheless interesting to get a more specific confirmation of the fact.
Of course, it’s worth noting that there appears to be a larger change coming to the auxiliary button on the top of the brake hoods.
Images from La Vuelta show a new larger button placed on the inside of the top part of each brake hood, instead of directly on top, as on the ST-R9270 shifters.
As with the rear derailleur module, the filenames of the leaked images appear to confirm the part name for the new shifters will be ST-R9370.
A closer look at the new power meter
In contrast, substantial change looks to be confirmed for the groupset’s new power meter crankset.
Ever since Shimano began making its own power meters back in 2017 (alongside the launch of Dura-Ace R9100), it has taken its existing integrated crankset design – which combines the driveside crank, the chainring spider and a 24mm steel spindle – and retrofitted the relevant sensors to each crank arm.
Now, though, we have our strongest evidence yet that Shimano is moving to a direct-mount crankset design, with the chainring spider mounting separately via a splined interface.
This design is likely borrowed from its mountain bike groupsets, such as XTR Di2 M9200.
Instead of a hollow axle, though, it seems almost certain that the power meter battery will be housed in there (as on current Shimano power meter cranksets), because there are now battery ports on the crank arm sensors themselves.
What looks like a single, centralised charging port is placed at the base of the driveside crank arm.
Somewhat frustratingly, the shape of the port suggests this could require a different charging cable from the Di2 groupset itself. That would represent a change from the current design where the same cable can be used to change both the Di2 R9200 groupset and the power meter (just not concurrently).
Although this is purely speculation, we’d suspect this change comes with an eye on improving the performance of Shimano’s power meter cranksets – which, it’s fair to say, have garnered a poor reputation for accuracy over the years.
Aside from the fact an inaccurate power meter simply doesn’t live up to its promises, the UCI is actively exploring the possibility of using rider power data to catch dopers – so having a power meter that measures a rider’s power output both accurately and consistently is a must for the Japanese brand this time round.
There have been some suggestions over the years that Shimano’s asymmetric crank design has been the root cause of its accuracy problems, which could help explain the move to a more symmetrical design as seen here.
As with the other parts, the image filenames suggest the power meter part name will be FC-R9300-P.
Is Shimano Dura-Ace Di2 R9300 almost ready?
Given the changes between the current-generation Dura-Ace groupset and this upcoming one appear to be fairly small – based on what we know so far, at least – some have questioned whether what we saw at La Vuelta was simply a ‘work in progress’.
These leaked images add weight to the idea that it’s much closer to a finished product, however.
Shimano (and other companies) typically make such regulatory fillings for products when they are ready to go, rather than in a prototype phase, after all.
Of course, that doesn’t mean it will released in the immediate future, and there may well be much that we don’t yet know about the new groupset and its functionality.
But these leaks, and the recent release of new Dura-Ace R9300 wheels, certainly imply a full launch of the next-generation Dura-Ace groupset isn’t too far away.
