Shimano Dura Ace R9270 Di2 Road Groupset – long term review

The groupset debate is a pretty common thing among cyclists, with seemingly everyone having their own expert opinion or preference. As with any other component, I opt for a more level headed approach, based on facts and my own experience. Having extensively ridden and worked every major release in the past few years (R9050, R9170, R9270, GRX Di2, eTap, eTap AXS, SR, SR EPS), and not being tied to any particular brand, I have gathered a wealth of experience on the topic.

To be perfectly honest, I was not exactly blown away with the release of the latest generation of Shimano 12spd groupsets. The stellar performance of R9170 on most fronts is responsible for that in a big part. After the slightly reluctant switch however, I was really happy with how it went, even though the transition was not exactly problem free.

The first bike I had outfitted with the new Shimano kit was my road race bike – the Factor Ostro VAM. You can read all about the experiences with that bike in my previous post.

One of the big upgrades, apart from the transition to 12spd, is of course the semi wireless nature of the new system. This leaves a big question regarding the installation:

Is the setup easier than before?

The short answer is yes, but it is not always as simple as that. Putting together a traditional, fully wired Di2 setup arguably requires a lot of consideration, knowledge and experience and one cannot simply jump in head first, without navigating the relatively wide array of available cables, junctions and small components. With road bikes, this kind of hassle is now mostly done with when opting for the 12spd group.

The internal battery (BT-DN300) is still an important part of the system, as it powers both derailleurs. To accommodate the wireless setup, it now also acts as a junction, and is equipped with three connectors instead of one. The wiring itself has been updated as well, with a new connector sporting a much smaller diameter (EW-SD300), with the wire itself being slimmer in cross section. Since most frames are housing the battery in the seatpost, or the bottom bracket area, the choice of wire lengths is not as critical as it used to be. I generally go for a 1400m unit for the RD and 900mm for the FD to be on the safe side, as the excess can always be neatly stoved inside the frame. At first, things have not been that simple in terms of routing the wires, as there was no routing kit available from any of the tool brands.

The Park Tool IR 1.3 kit has been updated in early 2023 with a new tool that clips on to the SD300, making the whole process a lot quicker. As for the battery, it has the same external dimensions as the units that came before, so most mounting options will still work. The only possible problem that can appear is with end port location – it now has a triangular shape instead of round, which had me cutting out the clamping section on some mounts with a rubber inserts. Newer framesets seem to have updated this as well, so at this time it should no longer be an issue. The third and final port on the battery is reserved for wired setups – optional for drop bar setups and required for TT/Tri bikes.

With these, everything related to the cockpit wiring remains unchanged, just like the TT shift buttons (SW-R9150/9160) and levers (ST-R9160/9180). These have not been modified at all, so still use the older EW-SD50 wiring. The one exception is the lack of the A-junction in wired setups, as this function has been replaced by the rear derailleur. In most cases, there are four or six shift units that need to be wired together using EW-SD50 wires, EW-JC41 junctions and EW-JC130 split wires. This SD50 harness needs to connect straight to the battery, using the new AD305 adapter that enables the connection of one SD50 and one SD300 wire.

The rear derailleur itself has undergone a fairly large update, although the typical Shimano features, such as the Shadow plus parallelogram and direct mount hanger attachment, have luckily been preserved. The biggest change visually is the longer derailleur cage, that now accepts a cassette as large as 34t. Shipped with the RD, there are three small parts that previously have not been included. The first one is a small rubber gasket that fits around the wire port, increasing the waterproofing of this connection (not that I would have ever experienced water ingress in this area). There is also a small plastic hook, that plugs into the hanger bolt and guides the RD wire so it does not get tangled in the drivetrain. While this is a nice concept, I find that on most bikes it does not quite do the job as the wire just slips from underneath it. The third part is a Sram-style adjustment guide for the B-tension, but honestly, I have not found this particularly useful, and I went for the traditional eyeballing method in nearly all instances.

The magnetic charging port is now also located at the back of the RD, making it pretty accessible, which I think is slightly more convenient than earlier. The new EC300 charging cable ends in a classic USB-A connector (maybe USB-C would be more appropriate these days) and is 1.5m long, with no switching adapter included. It all works pretty well in practice, but I would have preferred a longer option for added convenience.

There are two more new additions to the rear mech, namely the function button and the RGB control LED. Many have complained that the shifting can now only be adjusted via the app, but the opposite is true actually. Holding the function button still takes you to the micro adjust menu, just like with the old system, indicated by a multicolour flash from the LED. With a short press, you can still switch between the pre-programmed shift modes or activate the Bluetooth pairing function, indicated by blue flashes from the LED. Reaching the button itself is quite finicky in my experience, and I find myself still having to look for it even after setting up dozens of bikes with this system. Mid ride adjustments this way are now completely out of question, although luckily, it is possible to program one of the buttons on the hoods to act as an additional function button. I have used this method on my bikes and it certainly make life easier, although some people might miss one of the hood buttons that are delegated this way. Front shifting can also be adjusted through the function button, in the pre-determined gear combinations: big ring-smallest cog, big ring-biggest cog, little ring-biggest cog. For the adjustment to be correct, you need to perform the adjustments in this exact order. With all these additional capabilities, the RD has practically become the brain of the system, which houses all the adjustment and also takes care of the wireless communication with both the shift levers, and also your phone or bike computer when set up that way, eliminating the need of a separate wireless module, such as the EW-WU111 used earlier.

Packing all of this functionality into the rear derailleur makes it the single most expensive component of the whole system (maybe except the power cranks, but those are not easily damaged in a crash), which is probably not great news to aspiring crit racers, juniors or cyclocrossers, to whom crashes might be a common occurrence. With that said, I have yet to see an RD that failed due to crash damage – the thing seems to be relatively sturdy, even at the Dura Ace level. The Ultegra and 105 versions share all of these features, with the only difference being cheaper materials and a heavier final weight. The biggest difference is perhaps in the cage itself, as the DA version is made out of carbon fibre, and the others made out of stamped aluminium. One weird thing that splits the two is the lower limit of the derailleur. On 11spd Di2 systems, the RD would not go lower than the 3^rd sprocket on the cassette when shifted to the little ring at the front. I find this feature to be quite useful, as you can use a longer chain and thus have less tension on the big-big combination. The Dura Ace RD still does this, but Ultegra goes all the way down, for unknown reasons.

Significant changes have been implemented into the front derailleur as well (at DA and Ultegra level, 105 Di2 keeps the older FD design), with a smaller, sleeker overall design and a faster stepping motor. The installation process is the same as before, with the cage plate mounted parallel to the chainrings and secured in place with the positioning bolt. This in fact is the last physical adjustment bolt present, as the limits and trim are now adjusted electronically through the eTube app or function button (much like Campagnolo EPS). One feature I am not really a fan of is the guide tab of the Di2 wire entering the front derailleur. It is even trickier to install than before, plus on some configurations it can significantly reduce the clearance between the tire and the FD. Luckily, you can just plug the wire in without it and secure it with a small zip tie, like I have done on my gravel bike for example. Arguably, this problem could have been removed entirely by positioning the entry port straight down for example, but I assume this choice has been made due to packaging constraints. Despite the design overhaul, the FDs are still compatible with standard chain catchers, such as the trusty K-Edge Pro that I use on all of my bikes.

Perhaps my favourite part of the redesigned groupset are the new brake levers. These improve on two key areas that I have previously found lacking. While the 11spd versions were really compact, the texture of the rubber hood caused me quite a lot of blistering in the palm area. The longer, wider shape greatly improves the hand comfort while the taller and bulkier top section also provides more purchase and support without being intrusive or oversized. The second upgrade comes in the form of the servo wave piston engagement taken over from the MTB and gravel groupsets. This design creates a non-linear style of travel at the master cylinder of the lever, which improves the feel of control and modulation. While this has not really been an issue for me on the road, I did find the old brakes to feel quite dull in low grip or off-road scenarios, so this really is a welcome change. Lever reach can still be adjusted in a relatively wide range, with the 2mm adjustment bolt accessed from below the lever like earlier. Bite point adjustment is also offered, although it is not a feature, I would really find useful. One neat new touch that I have discovered though is the little notch on the plastic body at the back of the hood, making lever angle adjustments versus the handlebar a lot simpler to get right.

Apart from the structural changes, one thing we cannot really miss when talking about the levers is the fact that they now operate wirelessly and communicate directly with the rear derailleur through a proprietary protocol. Due to the wireless design, they now also need separate power sources in form of CR2032 batteries located at the side of the levers. These are said to last a couple of years of regular use, so I cannot comment on their durability just yet.

The levers also play a significant role in the process of bleeding the brakes. The steps themselves have not really changed compared to the previous version, but there are small refinements that have been made throughout. The first one is the new, larger bleed funnel that bolts directly into the lever without the adapter that was previously required. The large volume also enables for a longer initial push of oil, taking more air out of the system initially, speeding up the whole process. The thread of the bleed screw is still plastic though, and sits at an awkward angle relative to the hood body, so caution is advised when threading the screw or the bleed funnel in – I have seen quite a few units that have been damaged this way. The good news is that the head of the bleedscrew has been upsized to 2.5mm, improving the durability.

Even though the levers are primarily designed to be used wirelessly, there a still 2 wire ports on each side. Apart from the possibility of a wired setup, these enable the connection of the new diagnostic tool (SM-PCE2), as the levers themselves cannot be updated through Bluetooth, and also the two new satellite shifter options – SW-RS810T and S. Both of these are essentially the same compact micro switch, but they are supplied with a different wire length and mounting interface to fit their respective designated locations (Tops, Sprint). Since I use aero handlebars on all of my bikes, the Tops version does not really suit my use case, but I really like the new sprint version. The compact design is a massive improvement compared to the bulky SW-R9150s that came before, with just the tip of the switch sticking out from underneath the bartape for a neat look. They are in fact very similar to the first gen SW-R671s from the early days of Di2. As for the electronics, these are no longer a separately programmable standalone shift option like the SW-R9150. Instead, they are just a microswitch that extends from the levers, and all of the functionality is adjusted from there. The connector is also different from the regular SD300 wires, with a little tab across, which means that it can only be connected to a specific location at the levers.

One more thing left to note is the durability of the levers themselves. While the hoods don´t really show many signs of wear even after a year of use, I have been unlucky enough to subject them to some crash testing as well. While the old levers have been notoriously sturdy and could certainly survive some abuse, unfortunately that no longer seems to be the case. Earlier this year I have experienced a wipeout in a corner of a descent, with the bike just sliding across the road in a relatively uneventful manner, but I have still managed to brake both levers (with everything else remaining intact). The tall top section that houses the wireless electronics is now a hollow structure,
which does not seem to be that robust.

While there was nothing inherently wrong with the old two-piece brake calliper design, the updated units use a completely different single piece construction. The biggest change that Shimano advertise is the increased pad clearance. Combined with my disc brake tricks, these can be set up with a really decent amount of room between the pads and the rotor. This is a truly welcome change compared to previous generations of road disc brakes.

There are other, more subtle but still very useful updates as well. One of them is the new banjo design, that is now recessed into the side of the calliper and is operated by a 3mm Allen key, as opposed to the awkward 7mm spanner top mounted attachment. This simplifies the bleed process, as the frame no longer restricts access while bleeding. The only gripe I have here is that the small rubber caps covering the aforementioned bolts are really easy to lose – they tend to fall out regularly. The old ceramic pistons have also been ditched in favour of a plastic composite variant. With the number of cracked ceramics I have seen, this is hardly a surprise and definitely a useful upgrade.

The brake pads supplied are still organic, with the (probably unnecessary) cooling fins. The good news is that it is the exact same design as before, so in case you have some spares left over, they will still work just fine. The same applies for the brake hoses. The new groupset still uses the SM-BH90 standard, with identical attachments, so it is a one-to-one swap. This applies to the flat mount hardware as well, with the exception of the rear brake bolts. With the newer edition, only one of them has a tab for the safety pin, so you can´t interchange the two, as the other bore is not long enough to accept this protrusion.

Overall, the whole experience regarding the brakes has been bettered quite a bit, mainly thanks to the improved bleed process, better feel through servo wave and more pad clearance. The brakes are relatively silent under operation as well, particularly if you also use a pad fixing compound. One thing I have noticed though is the pads are quite prone to glazing under my kind of riding conditions (not much hard braking), which leads to a gradual decline of bite. I have successfully remedied the issue though with some sandpaper and degreaser. One minor niggle I have experienced with a number of Ultegra level levers is a loose retaining spring in the shift buttons, which buzzes on rough roads. While this does not affect functionality in any way, it can be quite annoying. Dura Ace levers do not seem to suffer from the same issue.

Initially, the brake rotors of choice for this groupset have been the MT900s, which arguably are much more resistant to warping under heat than the older RT900 variant. Under heavy braking though, it is still entirely possible to make them tick for a short period of time. The successors to these are the new CL900s, which have been quietly released last autumn. I have these on my TT bike, and I have to say I have not been able to make them produce any sound, even after a hard stop from 70km/h, which is quite impressive. What is less impressive is the general sturdiness and wear life of all of these ice-tech rotors. They are often out of shape even straight out of the box, and it takes some patience and a bending tool to get them right. For this reason, I have ordered a pair of the new Carbon Ti X-rotors in the CL variant, as these use a full steel braking surface. These should improve the brake feel and power too, not to mention the durability. Shimano uses an aluminium/steel sandwich construction, where it really does not take too much to wear the thin steel braking surface away. I tend to use 140mm rotors front and back on all of my bikes. These provide enough stopping power for my weight and riding conditions, plus they are also slightly sturdier due to the smaller diameter.

The 12 speed chains have been carried over directly from the MTB groups (M9100, 8100 etc). The plates are more sculpted than before, to accommodate the new Hyperglide design of the cassette, which provides ramping for both upshifts and downshifts. The top of the line offering still features SilTec coating and remains one of the most efficient chain options on the market, particularly when combined with immersive waxing like I have been doing for the past few years. The durability has also been impressive so far. I have managed to clock around 15000km on my first unit that I have changed just recently when it hit 0.5% elongation. This is the new recommended interval set by Shimano, instead of 0.75% on previous generations. Because of the MTB DNA, the chains are available in 116, 128 and 138 link variants, although road setups will all do just fine with the shortest version. They all come with quick links too – the rivet link has now been officially killed off by Shimano. While quick links are certainly a good think, I liked having the option to alter the length of the chain as this can be useful in some situations – like with changing to race specific gearing options for example.

Speaking of the cassettes, Shimano has now fully adopted easier gearing options and now provide a wide range 11-34 cassette even at Dura Ace level. The option I prefer to use is the gold standard 11-30, which now provides much nicer gearing steps at the middle due to the fact that it is now 12 speed. I find this particularly pleasing in TT scenarios. The big cassette is not too bad in itself either, although I do reserve that mostly for gravel bike use. In the specifications, a close range 11-28 is also mentioned, but I have never actually seen it available or used anywhere. Backwards compatibility is often tricky when adding speeds to a groupset, but luckily all of the new cassettes are fully compatible with the current Shimano HG freehub standard. The splines however have slightly been modified and can also fit onto the newer Micro Spline freehubs featured on Shimanos in house road wheelsets (I haven`t seen them on any other road options yet). There is also one tiny new feature that is handy when installing the cogs – each of them has a tiny mark stamped into it, highlighting the guide spline, making it easier to fit. Definitely a neat touch. Shifting performance in both directions is absolutely superb. The previous iteration was already extremely good, so I was sceptical about this at first, but it really is a marked improvement. The speed is impressive, despite having wireless actuation, but it is arguably even snappier on wired TT setups. One thing I have noticed with Ultegra level 11-34 cassettes is a clicking sound on the fourth largest cog – I could not make it disappear with any amount of fiddling with the adjustments. I do notice it quite a bit less though, now that the cassette has been worn in. On Dura Ace cassettes, I have never noticed any such thing.

The final mechanical piece of the puzzle is the crankset – which again has undergone a significant change in design. While it still features a bonded aluminium clamshell design with a 24mm steel spindle, the shaping is very different from the earlier versions and in my eye, also much more pleasing aesthetically. Shimano has also reportedly addressed the water ingress issues, which led to failures of many of the earlier cranks over time. While it certainly is a nice piece of kit, I never really use these Shimano cranks as I prefer a spider-based power meter option. Unfortunately, their own power meter option still does not perform according to expectations, so my preference is not changing for now. There is some good news is though – thanks to the more symmetrical shape of the new crankset, aftermarket manufacturers (most notably Stages) have managed to crack the problem and can finally supply a crank based dual sided power meter with reliable numbers.

A part of the crankset that I do have personal experience with are the chainrings. It took a while for the new R9200 54×40 set to available at my distributor, so I was really excited to test them out. Unfortunately, it did not go as well as I would have hoped. After installing them on my P2M NG SL spider, I have noticed during my first ride that the FD rubs in gear combinations where it would not do earlier. After some examination, I have realised that there is quite a bit of lateral play in the outer chainring, causing the interference. This certainly is not normal, so I have contacted Shimano about it and they have replaced my ring for a new one. Things got slightly better this time, but it still isn´t perfect. My customers using different cranks don´t report the same issues, so I am not 100% sure yet what to think of it at this point. For the meantime, I have reverted back to my old R9100 rings as they work just fine, even with 50 000km in them. As for differences in performance, I have not really noticed anything significant with the new rings in shift quality or noise reduction.

Shimano of course still offer their BBs to match the crankset as well. The choice of options is quite limited, with only BSA, ITA and PF41 options being available, so I rarely use these in my builds. They are not serviceable either, so in 99% of cases we stick to aftermarket options.

Because of the entirely new architecture, the software background for the new components has been changed as well. For desktop use, there is a new V5 version of the eTube diagnostics, coupled with the new SM-PCE02 linking device. While the FD, RD and battery firmware can be updated through the mobile app via Bluetooth, you need a wired connection and the diagnostic tool to update brake lever firmware and components of a wired setup. The linking device comes either with an EW-SD50 or SD300 wire attachment. My distributor only had the SD50 version, but you can easily transform it using the AD305 adapter and a regular SD300 wire to connect with the new levers. As you would expect, updates through a wired connection are performed much quicker than through the mobile app, which can be quite tedious. The rest of the app features work pretty well. I am quite fond of the FD adjustment process in particular. On my TT bike, I also use the programmable syncro shift option, due to the lack of extra buttons on my ST-R9180 brake levers. The graphic animation makes it pretty easy to set up to your liking, and in my experience, it is also perfect for riders just getting into cycling, so they don´t need to worry about front shifts. The single biggest annoyance for me is the pairing process for the wireless levers. This is done via scanning a tiny, pale QR code on the inside of the shift lever – a pain in the ass to be honest. Even though my workshop is pretty well lit, I often have to mess around with a bike light to make it more visible so that it actually scans. Granted, on your bike you might only have to do it once, but for me as a mechanic, setting up bikes every day, this is pretty annoying.

On my new Ostro VAM build, I have decided to give the R9200 54×40 chainrings one more chance. To my surprise, they worked out perfectly fine this time. I have thoroughly cleaned up all the mounting interfaces and used 8Nm of tightening torque instead of 6Nm. The chainring now sits nice and flush. More importantly, it also runs perfectly straight, without causing rub in any gear combination. I am really happy about this, as the old R9100s I was running have huge mileage in them, and frankly, they don`t look anywhere near as good.

All in all, the new offering from Shimano makes for a very compelling package, and in my book, it currently sits quite a bit above the competitor´s offerings. Sure, it is not perfect, but it is as close as you can get at this point in time.