What it is:Shimano’s latest revamp of its popular Dura-Ace Di2 and Ultegra Di2 electronic road groupsets.
Features:Semi-wireless format, 12-speed cassette, revised lever shape, Servo Wave variable-ratio brake lever design.
Weight: 2,507 g (claimed, complete disc-brake groupset without pedals).
Highs:Even-faster shifts, more controllable braking, updated lever shape, wider range and/or tighter gearing relative to 11-speed, choice of wired or semi-wireless setup, very long battery life.
Lows:Updated lever shape, disc-brake pad clearance isn’t much better than before, semi-wireless configuration and 12-speed might not be sufficiently strong arguments for upgrading.
It’s hardly a shock that Shimano has today officially unveiled its latest Dura-Ace Di2 flagship electronic road groupset with a 12-speed cassette and semi-wireless format. We’ve been expecting it for months, and there’s been no shortage of spy photos circulating online. But what few people expected is that — for the first time ever — Shimano has simultaneously launched the new Ultegra Di2 groupset, with all the same features and benefits.
What features and benefits, you ask? According to Shimano, the shifting is faster across the board, the brakes run quieter and offer better modulation and feel, it’s easier and more intuitive to install and customize, and there’s even a new lever shape that claims to address some minor issues with the outgoing model without alienating riders who love the current stuff.
And yes, there are some surprises, too, both good and bad.
Without further ado, let’s get into the shared details.
Say hello to wiredless
Probably the biggest story about the new Dura-Ace Di2 R9200 and Ultegra Di2 R8100 is that all of the components are no longer physically wired together. Instead, Shimano has moved to a semi-wireless format — hereby dubbed “wiredless” — where each lever is fully independent, but the derailleurs are connected to a new central battery.
According to Shimano, this wiredless setup offers the best of both worlds. With the explosion in fully internal cockpit routing, getting rid of the wires up front eliminates one of the biggest hassles of building up a new bike (particularly on the OEM side, which was perhaps a big driving factor in the decision). It’s one less wire to feed through a stem and/or steerer tube, one less junction box to hide somewhere, and a lot fewer wire lengths that shops have to keep on hand to join the various pieces together up there.
The system can be set up for wireless communication like this, but it can also be physically wired together like previous Di2 systems. Photo: Shimano.
The new Dual Control levers send commands directly to the rear derailleur, and each of those components now houses a bunch of extra wireless hardware that wasn’t there before. Also packed into the new rear derailleur is wireless communication for the associated E-tube smartphone app, the function button that used to live on the Junction A box, and a new charge port that uses the same plug as the current power meter. Handy LEDs are incorporated into all three of those components to provide visual information on things like charge level, setup status, and mode changes.
Why didn’t Shimano go the full wireless route, you wonder? Shimano says that maintaining a central battery for the two derailleurs makes for longer run times. SRAM claims an AXS rear derailleur battery will last for about 60 hours of riding, for example, while Shimano says the new Dura-Ace Di2 and Ultegra Di2 battery will last at least 1,000 km for most users, which unfortunately makes it tricky to directly compare the two based on official claims. Moreover, the 5,000 mAh Di2 battery sports the same shape and internal mounting options as before, so there’s no chance of accidentally leaving a removable battery at home when driving (or flying) somewhere for a ride.
On the transmitter end, each Dual Control lever is powered by a non-rechargeable CR1632 coin-cell battery. Why not the more common CR2032 cell, you’re wondering? Shimano says the CR1632’s smaller size is one of the reasons why the Dura-Ace Di2 and Ultegra Di2 lever bodies are so compact, and because the wireless protocol supposedly draws so little power, the claimed run time per lever is still a generous 1.5-2 years — about the same as SRAM AXS levers.
The new Dura-Ace Di2 R9200 Dual Control levers bear a strong resemblance to the previous edition for the most part, but the shape has actually been tweaked subtly.
Shimano says that, in addition to drawing little power, its proprietary wireless protocol also somehow transfers signals from the levers to the derailleurs faster than the previous wired setup, apparently due to updated circuitry that processes the commands “four times faster”.
Interestingly, Shimano claims the actual chain movement between cassette sprockets and chainrings is faster than before, too, although that’s mostly due to changes in the drivetrain tooth shaping (more on that in a bit).
Even more interesting? You can run the system semi-wirelessly if you want (and this is how I expect the vast majority of groupsets to be set up), but Shimano is still leaving the option to physically wire everything together. Run time in that configuration goes up a whopping 50%, which ultra-distance riders might find appealing. And if something were to happen to that connection, the system would revert to a wireless state to keep things up and running.
The new wires are markedly smaller than the previous ones.
Speaking of wires, Dura-Ace Di2 R9200 and Ultegra Di2 R8100 introduce yet another generation of E-tube. Shimano says the new EW-SD300 wires can handle more information than the current stuff, and the connectors are dramatically downsized to make them easier to fish through stubborn internal routing paths. Shimano didn’t make any mention of this, but I wonder if bike brands will follow suit and eventually reduce the size of wiring ports to match.
Going along with all of this is an updated smartphone app — offered for iOS and Android operating systems — with a more intuitive interface that allows Di2 users to quickly customize things like button functions, shift speed (as in, physically changing how fast the derailleur moves), shift maps, and so on.
12-speed, because one more is always better
Yup, the new Dura-Ace Di2 R9200 and Ultegra Di2 R8100 both now have 12 sprockets on the cassette. I know, I know, how many more gears are companies going to cram in back there before enough is enough, right?
Shimano’s arguments for stuffing yet another gear back there are the same as when we’ve gone from 10 to 11, nine to 10, eight to nine, and so on. Increasing the number of gear ratios nets two benefits: you either now have smaller individual steps for cassettes of similar overall range, or you get more range without having to deal with bigger jumps. Shimano will have 11-30T and 11-34T options at launch, with a more racer-focused 11-28T later on (just for Dura-Ace).
The five largest sprockets are made of titanium on the Dura-Ace side, while the rest are made of plated steel (all of the sprockets are steel for Ultegra, as usual). The largest six sprockets are split into two mini-clusters, with each sprocket riveted to an aluminum spider to decrease weight and increase stiffness relative to just flat-stamped pieces.
All of the cassette teeth feature Shimano’s latest Hyperglide+ tooth shaping (first introduced on the flagship XTR mountain bike groupset) for even-smoother upshifts and downshifts, particularly under power. Shifts inward to larger sprockets apparently haven’t changed much, but shifts in the other direction are said to happen 66% faster than before (which was already perceptibly faster than SRAM’s AXS drivetrains).
Up front are some revamped chainring pairings — 50/34T, 52/36T, and 54/40T — and as expected, the outer chainrings are hollow aluminum pieces for vastly improved bending rigidity (and shift performance) relative to more traditional flat-plate construction. Notably missing from that list is the traditional 53/39T, which Shimano says just wasn’t big enough for how much faster top racers are moving these days. But at the other end, the new cassette options mean that — for the first time ever — you can now get a factory 1:1 climbing gear with Dura-Ace and Ultegra without having to resort to aftermarket components. Yes, yes, and more yes.
If you choose the 50/34T chainrings and 11-34T cassette, you can finally get a 1:1 climbing gear on a Dura-Ace drivetrain.
Surely, you’re wondering about what the freehub body looks like, and I have some good news for you. Although it’s different from the current 11-speed spline pattern (more on this in a bit, too), the new cassette has been designed to be backward-compatible with existing 11-speed hubs and wheels. So no, if you already have a fleet of wheels in your arsenal — or even just one wheelset that you absolutely love — you can continue using them even if you decide to make the move to Shimano’s new 12-speed groupsets.
You’re probably also wondering about drivetrain wear, and unfortunately, there’s no clear answer from Shimano.
“We don’t state specific mileage data as there are too many variables we can’t control to give an accurate number,” said brand manager Nick Legan. “But importantly, Shimano 12-speed chains have the same durability as our legendary 11-speed offerings.”
That said, this question has come up with every incremental increase in cassette sprockets over the years. Ultimately, it’s just never been the major issue people have feared it would be, and I don’t see any reason the story would be any different this time around, particularly given the anecdotal data from Shimano’s 12-speed mountain bike components.
The new freehub body looks very similar to the Micro Spline design that Shimano uses for its mountain bike cassettes, but it’s actually a larger diameter since it doesn’t have to accommodate a 10-tooth sprocket.
And if Shimano was so concerned about gear jumps and range, why not follow SRAM’s lead and start with a 10-tooth sprocket? Shimano says it was all about drivetrain efficiency. Although starting with a 10-tooth sprocket would have more easily provided more range in a smaller and potentially lighter package, the company says the hit in efficiency wasn’t worth the modest decrease in size or mass.
Shorter cranks, longer derailleur cages, and a mountain bike chain
Naturally, the rest of the drivetrain is wholly revamped as well.
The new crankarms feature the same Hollowtech II design as before, with the driveside arm using a two-piece bonded construction and the non-driveside arm using a one-piece forging. Shimano is yet again sticking to its tried-and-true 24 mm-diameter splined chromoly steel spindle for the widest possible range of compatibility with various bottom bracket shells, and the bottom bracket options themselves carry over from last year.
Opinions are bound to be mixed on the aesthetics of the new crank, but when has a new crank ever been received with universally open arms?
The chainring bolts once again feed through the crankarm spider tabs from the backside, and — of course — the bolt circle pattern is tweaked yet again from previous generations. It’s still a four-arm pattern, but old cranks won’t work with new chainrings, and vice versa.
More welcome is the addition of a 160 mm crankarm length for both Dura-Ace and Ultegra, and the latter finally gets its own dual-sided power meter option, too. The basic design of the power meters is the same as before, although the transmitter and charge port have been redesigned for easier access, and claimed accuracy has improved slightly from 2% down to 1.5%. According to Shimano, the new power meters will run for the same 300 hours as previous models before needing to be recharged.
Going along with the wider-range cassette options are new rear derailleurs, which feature a single, longer, pulley cage length that will work with every gear combination that Shimano offers, and that supposedly provide 60% faster movement than previous models. The Direct Mount mini-link up top carries through from the previous version, and it’s expected that the number of bike and frame manufacturers offering dedicated hangers will continue to increase moving forward.
The new Dura-Ace Di2 R9200 rear derailleur is an awfully industrial-looking bit of kit.
The additional wireless hardware on the rear derailleur increases the overall bulk a little, but it’s tucked away on the inner side of the derailleur body so there’s not much of a difference at first glance. If anything, the new derailleurs sport an impressively low profile even in their outermost position, presumably to help minimize the chance of damage in a crash.
Seeing as how Dura-Ace and Ultegra are still viewed within Shimano as being dedicated road groupsets, the company hasn’t bothered to incorporate pulley cage clutches. My guess is that they were deemed as adding too much weight for not enough benefit given the application, though I’d argue this was still an opportunity lost. While it’s true that the majority of Dura-Ace and Ultegra buyers aren’t going to be putting this stuff on gravel bikes, there are still plenty of bumpy paved and dirt roads out there that people ride with road bikes, and chain slap can be an issue there, too.
Remember how I mentioned earlier that one advantage of the central battery was decreased derailleur size? Shimano has certainly taken full advantage of that up front as the new front derailleurs are positively tiny with a claimed one-third reduction in frontal area. This presumably makes it more aerodynamic, but it also just looks a lot more elegant.
The new Dura-Ace Di2 R9200 front derailleur is substantially smaller than the previous one.
Linking everything together is a new chain — well, new to the road, at least. Since the sprocket-to-sprocket spacing on the cassette is the same as Shimano’s 12-speed mountain bike groupsets, Dura-Ace Di2 R9200 and Ultegra Di2 R8100 simply borrow existing chains from that side of the fence with no changes whatsoever. The plates are specifically shaped to mesh with that new Hyperglide+ tooth shaping, and there’s the same master link to join everything together, too.
As for the SPD-SL pedals and bottom bracket cups, they’re unchanged from the previous generation. No point in fixing what isn’t broken.
Quieter brakes, more control
Shimano hinted months ago that one of the primary targets for its new road groupsets was improved disc brake performance — not so much in terms of power (that’s never been a complaint with Shimano road disc brakes), but rather noise and setup. Both of those have been addressed with Dura-Ace Di2 R9200 and Ultegra Di2 R8100.
Pad clearance has supposedly increased by 10% on the new Dura-Ace disc brakes.
Although Dura-Ace uses a remarkably svelte-looking one-piece forged aluminum caliper body and Ultegra uses a two-piece setup, both feature a modest 10% claimed bump in pad clearance to provide just a hint more wiggle room when lining things up. Shimano is no longer using road-specific rotors, either. Instead, both groupsets now pair with Shimano’s existing mountain bike discs, which are not only a tad lighter, but also less prone to temporary heat-related deformation (that telltale “ting, ting, ting” you sometimes get after hard or prolonged braking).
On the service and maintenance front, both twin-piston calipers also incorporate a nifty new bleed port design with a more secure attachment point for the syringe and a separate valve to open or close the system.
Shimano has made some major changes to the other end of the system, too. Finally carrying over from the mountain bike side of the family is the Servo Wave lever pivot mechanism, which alters the leverage ratio at different points in the brake lever travel. From a practical standpoint, this means there’s less free lever travel before the pads contact the rotor for more immediate response, but then more precise control afterwards.
The Servo Wave lever design alters the leverage ratio throughout the stroke of the brake lever.
Updated lever shape and smaller satellite shifters
Changes to the new Dura-Ace Di2 R9200 and Ultegra Di2 R8100 levers aren’t limited to the inner workings. Like it or not, Shimano has tweaked the exterior shape, too.
The girth and general shape are very similar to the previous generation, but the bodies are actually a bit longer (4.6 mm when measured on the underside, to be more specific) so you’ve got a little more to hold on to, and the hood peaks are a hair taller than before. That change doesn’t alter things dramatically, but it does fill your palms more thoroughly if you’re a rider who likes to stretch their arms out over the hoods.
Overall, the changes seem to cater to current trends in lever placement with riders clocking them up higher on the bars.
Texturing on the hoods is minimal, but seemingly effective at maintaining a good grip with bare hands, even when wet.
The curve of the lever blades will feel familiar to anyone who’s been using Shimano controls for the past few years, but they’re now canted a bit outward so they more naturally fall within reach of your fingertips while on the hoods.
From an aesthetic perspective, the upper part of the lever is finished much like Shimano’s first-generation R785 Di2 Dual Control levers. It’s a minor difference in the grand scheme of things, but it also means the appearance of the levers doesn’t change much when you adjust the lever reach.
As for the shift buttons, there’s more height offset and a more pronounced texture differential so your fingertips can more easily tell them apart, and the inboard paddle now extends further toward to the tip of the brake lever for improved access from the drops.
The buttons have a bit more height differential than before so your fingers can more easily tell them apart.
Each lever has two accessory ports, so unless you go with the optional fully wired setup, you can run satellite shifters on the tops and down in the drops if you wish. Shimano has also reverted back to “dumb” switches like the first-generation Di2 stuff, so the buttons themselves are much smaller than the current stuff for easier and more flexible placement.
Lots of updated wheels, and Ultegra finally goes carbon
Going along with all of the new components is a full suite of new wheels for both Dura-Ace and Ultegra, in 36, 50, and 60 mm depths, all in tubeless-compatible clincher formats with more modern 21 mm internal widths and 28 mm external widths that the company claims are more aerodynamic than previous versions of similar depth. For the first time, Ultegra rims are now carbon fiber, too, with the same shapes as Dura-Ace.
Tubular versions will be offered for the Dura-Ace wheels, but only for the European market. And once again, there are no standalone hub options.
Both Dura-Ace Di2 R9200 and Ultegra Di2 R8100 offer three all-new wheelsets, and they seem far more competitive with similar models from other brands than they did before.
Rear hubs feature a similar internal design to Shimano’s latest XTR with a helical-style driver mechanism in lieu of Shimano’s more traditional pawl-type freehub. Engagement speed is reasonably quick at 10°, and Shimano claims the design offers 63% more “driving rigidity” — whatever that means. Two-to-one spoke lacing is used on rear wheels for more balanced spoke tensions left to right, and there’s even now a sprinter-special WH-R9250_C60_HR_TL model with thicker front spokes and front two-to-one lacing for riders that want more rigidity.
Seasoned mechanics will be happy to hear that Shimano is carrying on with cup-and-cone bearings across the board. Though they seem more old-fashioned than sealed cartridges, they’re actually more durable since they can handle so much more load without pitting, they’re easy to service (and are actually serviceable instead of just being replaceable), and can be adjusted for optimum preload. Two thumbs up.
Now, back to what I was saying earlier about freehub bodies and cassette compatibility.
Shimano has always taken an obsessive approach to shaving grams on Dura-Ace. A look inside one of the cassette spiders is good evidence of that attitude.
The new 12-speed cassettes do have a new spline pattern that’s backwards-compatible with existing 11-speed Shimano freehubs. It looks very similar to the Micro Spline pattern that Shimano uses for its 12-speed mountain bike hubs, but it’s not quite the same. Either way, the advantage of the new spline is that you can now run aluminum freehub bodies without the individual sprockets digging in the same way since there’s twice as much surface area to distribute the load.
As such, Dura-Ace wheels will now get aluminum freehub bodies for the first time — which will only work with new 12-speed cassettes, not older 11-speed ones — while Ultegra wheels carry on with steel. My guess is that aftermarket hub and wheel brands will quickly follow suit with dedicated 12-speed aluminum road freehub bodies of their own, assuming Shimano is open to licensing the design.
Some backward compatibility, but not nearly enough
OK, it’s time to address one of the elephants in the room: compatibility with existing 11-speed stuff. Let’s just say you’re not going to like the answer. The chains are narrower, the sprocket-to-sprocket spacing is tighter (though the same as Shimano’s 12-speed mountain bike drivetrains), and while the bolt circle diameter for the chainrings is the same 110 mm, the actual location of the arms is different so there’s no mixing and matching there, either.
According to Shimano road product manager Dave Lawrence, “Basically anything 11-speed will not be compatible with 12-speed.”
That said, time (and some experimentation) will tell whether the new brake calipers will work with older levers, which could provide some benefit in terms of brake rub. Since the mountain bike rotors have always been compatible, that’s a good option for riders seeking to get rid of that heat-related ticking (and one pro teams have already been using), and Shimano thankfully hasn’t introduced yet another disc brake pad size.
Adapting older 11-speed levers to work with the newer 12-speed stuff is clearly possible since Shimano has done just that with the time trial and triathlon stuff. Photo: Shimano.
One of the benefits of electronic drivetrains is that they can theoretically be programmed to move however they need to. 10-speed? 7-speed? Suntour’s uneven Accushift? It should also be possible, and aftermarket brands like Archer Components have proven it can be done. The question, however, is whether a brand deems it worthwhile to invest the time to offer that level of compatibility. Shimano clearly has not in this case.
What makes the situation even more frustrating is that Shimano has tacitly admitted such backward compatibility is more than possible; it’s already done it, in fact. Given the limited market, Shimano didn’t bother to make all-new 12-speed components for time trial and triathlon bikes. Instead, Shimano developed the AD-305 adapter box that connects the old controls with the new derailleurs and battery. One end accepts the existing EW-SD50 wire, the new EW-SD300 goes into the other, and the rest is handled via firmware updates.
This obviously doesn’t provide the same wiredless benefits as the full system, but it works nonetheless. Clearly such a combination would have been feasible with the road components, but Shimano simply decided not to offer it. It’s a massive disappointment.
What about mechanical drivetrains? Or rim brakes???
Time to talk about the other elephant in the room: mechanical drivetrains and rim brakes.
This will come as a shock to many, but Shimano is walking away from mechanical road drivetrains at the high end, which includes Ultegra. Indeed, what was arguably the best all-around higher-performance mechanical road groupset value on the planet is no more. Shimano will continue to manufacture and sell 11-speed mechanical Ultegra groupsets for some undetermined amount of time — probably another model year or so — but after that, it’s all electronic from this point forward. Got a soft spot for Dura-Ace mechanical? Better start digging around on eBay even harder than you were already, because it’s officially extinct.
There’s better news on the rim brake front, though.
The brake calipers themselves are unchanged, but Shimano has taken the existing 11-speed Di2 rim-brake levers and modified them to accept the new EW-SD300 wires. This means you’ll still have a wired electronic drivetrain (big deal), but you’ll at least have the option of running the new 12-speed drivetrain with traditional rim brake calipers.
A note on packaging
Compatibility kerfuffles aside, there’s one indisputable bright spot to all of this. Shimano’s packaging has long been clearly labeled with what-goes-where in terms of recyclability, but the multiple plastic bags and stretchy plastic sheets could almost never be tossed straight into municipal recycling bins. Starting with the new Ultegra and Dura-Ace, Shimano has moved to 100% paper-based packaging, with more basically-finished paperboard boxes outside and what basically amount to cookie bags on the inside.
The new packaging for Dura-Ace and Ultegra is wholly paper-based, and will keep a lot of plastic out of landfills.
It may not seem like a big deal, but keep in mind that Shimano sells an awful lot of stuff. And any shop mechanic can attest to how much of the old plastic stuff ends up in the garbage can at the end of each day.
Weights, prices, and availability
Shimano says complete bikes with the new Dura-Ace Di2 R9200 and Ultegra Di2 R8100 build kits should be available immediately from various partners, though invariably in limited quantities. Aftermarket part availability is slated for the beginning of October, and even that is expected to start as a trickle, at least relative to the historically high demand.
As for weights, riders who were hoping for big reductions will be disappointed. Claimed weight for the complete Dura-Ace Di2 R9200 groupset is 2,507 g, which amounts to a 21-gram gain over the previous generation. Likewise, Ultegra Di2 R8100’s complete claimed weight of 2,707 g adds up to an 8-gram increase over the outgoing version. Nevertheless, that actually seems pretty good considering Shimano has added a 12th sprocket out back.
Individual claimed weight and prices are as follows (UK and EU prices are TBC).
Is 12 really that much better than 11?
At this point, surely what you’re most interested in knowing is whether the new Dura-Ace Di2 R9200 or Ultegra Di2 R8100 is worth the price of upgrading. Shimano doesn’t yet have media samples of Ultegra for us to test, but I have been using a Dura-Ace Di2 R9200-equipped Low Bicycle Disc MKii for the past few weeks.
Want to know what I think of this fancy new Shimano stuff? This article is long enough as it is, so head over to the Dura-Ace Di2 R9200 review to find out.
More information can be found at www.shimano.com.
Shimano Dura-Ace Di2 R9200 Gallery
The hoods are almost 5 mm longer to provide more room for your fingers to wrap around the lever body.
The inboard shift button extends down a bit further than it used to for easier access from the drops.
Yep, there’s still the extra button up on top of the levers. Use it as an additional shifter button, to change pages on your wireless-enabled computer, or for several other optional functions.
The levers and rear derailleurs all incorporate LED indicators.
Lever blades are now canted outward a bit.
The QR code comes in handy when setting up the associated smartphone app.
The long cage is designed to accommodate every possible approved gearing combination. Not everyone will like the extra length, though.
The low-profile design is supposed to help minimize damage in a crash.
A lot of the hardware has been moved to the inboard side of the derailleur.
Woo hoo! Check out the little clip to keep the wire tucked up and out of the way.
Shimano is continuing on with the mini-link design up top. A number of bike brands will offer direct mount hangers to eliminate that little part.
This area of the Dura-Ace Di2 R9200 rear derailleur directly incorporates an LED indicator, the function button that once lived on the Junction A box, and the wireless capability of the old D-Fly module.
The charge port is the same as what’s used on the power meter.
There’s no carbon fiber in the new Dura-Ace Di2 rear derailleur, but there is a lot of aluminum to help keep the weight down.
The black anodized outer cage plate on the Dura-Ace Di2 R9200 front derailleur looks … angry.
Q-factor hasn’t changed from previous Dura-Ace models.
The incredible stiffness of the hollow outer chainrings is a key reason why Shimano’s front shifting is so good.
Crankarm construction supposedly hasn’t changed from previous versions, according to Shimano. The driveside arm is still a two-piece clamshell, and the bond line is clearly visible.
The new Dura-Ace crankset still uses a 110 mm, four-arm BCD, but the chainrings aren’t compatible between generations.
The non-driveside arm is a one-piece hollow forging.
Shimano is sticking to 24 mm-diameter steel spindles and dual pinch bolts.
Nope, definitely not used to seeing stuff like this from Shimano.
Bottom brackets haven’t changed, either.
Whether you think moving to 12 sprockets over 11 is worthwhile will likely depend a lot on where you ride, and the type of riding you’re doing. For plenty of folks, 11 will continue to be just fine.
Shimano has attached the six largest sprockets to two mini-clusters to help reduce weight and minimize flex.
Individual sprockets have plenty of material removed, too.
Chains are shared with Shimano’s 12-speed mountain bike groupsets.
Shimano has a new tool to help you dial in the chain gap.
The new BT-DN300 battery (bottom) has the same size, shape, and capacity as the old one (top).
Whereas the old Di2 battery has just one port, the new one has three.
Since the new battery uses the same casing design as the old one, it offers the same mounting options. The seatpost one will continue to be particularly popular.
There are new tools to go along with the downsized wires, too.
Dura-Ace calipers are made of a one-piece aluminum forging.
Shimano clearly doesn’t want you to take the caliper apart.
Rotors are now borrowed from the mountain bike side of the family, but still feature Shimano’s Ice Tech technology.
Bleed hoses now attach more securely, and there’s a separate spot to open and close the valve.
Servo Wave technology doesn’t seem to have changed the overall power available, but it’s designed to make it more accessible.
While a lot of companies reach for carbon fiber hub shells to save weight, Shimano is sticking to what it knows and does best: forged aluminum.
Straight-pull spokes are anchored in complex flanges.
External nipples for easier servicing.
Rear wheels feature two-to-one lacing patterns to help equalize tension.
Shimano continues to use adjustable cup-and-cone bearings throughout.
Shimano says the rear hubs offer better “driving rigidity” than before.
The new freehub body looks very similar to the Micro Spline design that Shimano uses for its mountain bike cassettes, but it’s actually a larger diameter since it doesn’t have to accommodate a 10-tooth sprocket.
Doubling the number of splines certainly helps distribute the load to reduce how much individual sprockets will dig into the freehub body, but I don’t think it’ll eliminate it completely.
The freehub body is still keyed to ensure every sprocket is properly installed.
Shimano Ultegra Di2 R8100 gallery
The Ultegra Di2 R8100 levers look quite sleek.
As with Dura-Ace, the new Ultegra Di2 R8100 levers have slightly longer bodies.
Ultegra brake lever blades are canted slightly outward just like Dura-Ace.
The integrated LED indicators are nice to have, but I wouldn’t have objected to some fun sound effects, too.
Yep, “secret” buttons are alive and well on the new Ultegra Di2 R8100 levers, too.
The more pronounced height differential on the Ultegra Di2 R8100 shifter buttons makes it a little easier to tell them apart.
Subtle texturing on the Ultegra Di2 R8100 hoods.
Lever reach adjustment is tucked away back here.
Shimano has done a remarkable job getting the hoods to fit tightly and securely around all of this stuff.
One of my favorite things about the new groupsets? The lever clamp bolt is extremely easy to access, and it’s a genuinely straight shot to the head with just about any Allen tool.
Plug in satellite shifters here, or use one of the ports to physically wire everything together.
The rear derailleur is offered in a single cage length to accommodate all potential gearing options.
As with Dura-Ace, the Ultegra Di2 R8100 rear derailleur sports an impressively low profile.
There’s a lot of extra hardware on the new Ultegra Di2 R8100 rear derailleur, but it’s mostly hidden away back here.
Shimano is sticking to non-oversized pulleys, saying the minor decrease in friction isn’t worth the negative impact to shift performance.
This little clip for the rear derailleur wire is so brilliant that it’s a wonder that it wasn’t introduced earlier.
Direct Mount or not? It’ll be your choice in many cases, depending on what types of hangers are offered by bike brands.
The function button that once lived on the Junction A box is now back here on the rear derailleur.
The charge port is hidden behind a handy little door.
The new Ultegra Di2 R8100 front derailleur isn’t much bigger than mechanical ones.
I’m not sure exactly how Shimano managed to make its new Di2 front derailleurs so small, but I’m glad it happened.
Whereas Dura-Ace uses an aluminum outer cage plate, the Ultegra one is all-steel.
The new Ultegra Di2 R8100 crankset sports an all-matte finish and a simpler shape.
Q-factor is unchanged from the previous Ultegra crankset.
The driveside crankarm on Ultegra continues to be a two-piece clamshell affair. A peek at the backside of the arm reveals the bond line around the circumference.
The one-piece forged aluminum non-drive crankarm looks simple and elegant.
Chainrings are similar to the previous Ultegra ones, but they’re not cross-compatible.
You can see where the glue squeezed out between the two halves of the Ultegra outer chainring.
Ultegra gets most of the same gearing options as Dura-Ace.
How hard are parts to come by? This Ultegra photo sample bike has a Dura-Ace cassette on it instead of the all-steel unit it’s supposed to have.
Whereas Dura-Ace calipers are a one-piece aluminum forging, Ultegra is a two-piece affair.
Heat management is still a prime concern for Shimano, and the standard pads are finned to help dissipate thermal energy into the surrounding atmosphere.
Ultegra gets the same updated bleed process as Dura-Ace.
No more road-specific rotors! These are shared with Shimano Deore XT.
Braking power is still a high point for Shimano’s new Ultegra and Dura-Ace, but it now comes with a bit more control.
Shimano is using carbon rims on Ultegra wheels for the first time.
Ultegra wheels use straight-pull spokes like with Dura-Ace, but the hub flanges aren’t quite as fancy-looking.
Cup and cone FTW.
Dear Shimano: thank you for making it easier to true your wheels.
Rear wheels feature two-to-one spoke lacing.