I’m hardly breaking new ground here with a SRAM Red AXS vs Shimano Dura-Ace groupset showdown. This is a comparison pretty much as old as the two companies in question. Still, these are the top two options on the market. If you choose either one it’s a big investment and it’s an endlessly fascinating thought experiment.
One thing before we go further. I said SRAM Red AXS vs Shimano Dura-Ace represents a battle of the top two groupsets, and now there are people out there yelling about Campagnolo. I promise, I didn’t forget anything.
Campagnolo is a legendary brand, but it’s also rare. I think for many people, if you like Campagnolo you are choosing it. For everyone else, our list of bike reviews are filled with choices that come already built up with either SRAM or Shimano. It only made sense to start with this matchup first.
That still leaves the question of what’s new here? I don’t want to copy any of the other articles that exist, and you don’t want to read a copy of a copy. Instead what I did is build two incredible bikes and spend a summer riding them.
For many, myself included, new bikes are as much about the build as the arrival. Thinking about every detail and getting everything perfect is part of the fun. This article is about SRAM Red AXS vs Shimano Dura-Ace but it’s also about building two super bikes and riding them for thousands of miles. If you want the details on the bikes, jump down below. I’ve covered all my decisions.
To start things off, I’m just going to dive in and cover a few of the differences I think matter. From there I’ll tell you which one I tend to choose and finally I’ll cover all the details about the two bikes I built for this test.
Derailleur clutch +1 point SRAM
Cavendish rides (rode?) Shimano groupsets and you might have noticed a trend. At the end of most (maybe every, I didn’t count) sprint finish he drops his chain. When we talked to Cavendish about it he said, “It’s not something I worry about because it happens after the finish.” Which is great for him in a race setting, but you might not be in a race setting and a clutch would eliminate the issue.
I had a friend tell me “Your sprint is about as strong as a wet cabbage leaf,” and still, I managed to drop the chain at the end of a sprint. Unlike Cavendish though, I had plenty more riding to do and a dropped chain meant an unnecessary stop. Also, the day that happened it wasn’t even the first time it dropped.
An hour or two earlier in the ride, I dropped a chain because of a rough road. The route I was on transitions from a smooth flowing descent into a very rough road. The chain bounced off but I didn’t realize it happened. Carrying a bit of momentum into the flat I casually rotated the crank while coasting and left the Dura-Ace crank looking like I’d dragged it on the ground.
The Shimano cranks scratch easily anyway. Do yourself a favor and put some helicopter tape on yours before it looks like mine. That won’t fix the chain drops though.
Shimano needs a clutch. A clutch would stop the violent bounce at the end of a sprint and it would also stop the chain bounce that happens on rough roads. Shimano has a clutch on GRX systems and SRAM has one on all the road groupsets. The downsides are minimal and are far outweighed by your chain staying on the crank. Not having it makes no sense.
Brake fluid +1 point Shimano
When it comes to the clutch, there’s a number of reasons floating out there about why Shimano doesn’t have one. At the end of the day though, SRAM does and it works. There’s a similar dynamic at play between the brands when it comes to brake fluid choices.
SRAM uses DOT fluid. It’s corrosive making things a hassle when bleeding brakes. Do it right and you’ll never have an issue but make a mistake because it’s been a year since you last went through the process and it’s a panic situation.
SRAM will tell you that DOT fluid is superior and that’s why the brand uses it. We can debate about whether that’s true but it’s irrelevant. Neither brand is operating in a vacuum. SRAM uses a clutch and it works; Shimano uses mineral oil and it works. When there’s a clear advantage to a specific choice, and your competitor overcomes the downsides, it gets pretty tough to tout a theoretical advantage.
Batteries +1 point SRAM
Shimano has one large battery that connects to the front and rear derailleur inside the frame. It lasts longer but it makes everything more difficult.
Having no ability to swap batteries means no backup options. It’s already more difficult to charge since it requires plugging in the bike instead of popping off a battery, but when it’s dead, it’s dead. SRAM batteries are the same front and back and the rear always dies first. If you manage to ignore all the warnings and let that happen, just swap the batteries to get home. If you are really worried, bring an extra with you just in case. If you are about to leave the house and get a battery warning, just grab another battery instead of waiting to charge the bike.
I’ll also include in this section that SRAM turns on when you shake the bike while Shimano is harder to turn on. In day-to-day riding, the Shimano approach is annoying but it’s probably better for travel. SRAM solves this with easy to remove batteries.
Hood shape +1 point Shimano
This one is obviously subjective, but I think Shimano wins here. Everyone hated the previous generation SRAM hoods but I found them very comfortable to hold in an aero position. The new SRAM hoods reduced the size, seemingly in response to complaints, but it’s now an awkward shape to hold. On the upside, when you do hold it the bonus buttons tend to be in the perfect spot.
Shimano hoods haven’t changed much in a long time and they continue to be smaller and more comfortable. When I switch bikes, the Shimano hoods feel like coming home.
Software +1 point SRAM
I’m sure there’s a number of people losing their minds as I review batteries and software on a bike but this is the reality. Both Shimano and SRAM have apps that allow you to update the firmware, perform micro adjustments of the derailleurs, and specify exactly how the system works.
In truth both are decent but SRAM just edges out Shimano for a couple of reasons. The big one is the firmware update situation. SRAM is completely wireless. Shimano is wireless unless you need to update the controls. Since the controls aren’t physically connected to the rest of the system, Shimano requires that you connect them with a wire. It’s not all that hard but my shifters perpetually call for an update that will probably never come. My SRAM system is always up to date.
Then there’s the data you can get. Shimano will tell you overall gear usage rates (50 with 15, 17, or 19 are my most used) but that’s it. SRAM will tell you on an individual ride exactly where you used what gear and how much power you pushed. Most of the time this isn’t entirely necessary but if you are trying to figure out the right gearing for you, The SRAM AXS web tools are incredible.
It’s probably worth noting that you can actually use AXS web with a Shimano bike but there’s no ability to pick the correct gearing. It can still be useful, though, so perhaps you get the best of both worlds? I’m still giving this to SRAM because of the update thing.
Weight +1 point Shimano
On my scale SRAM Red AXS with a 46/33 power meter crank, 10-33 cassette, and dual 160mm rotors comes to 2,485 grams. Meanwhile, Shimano Dura-Ace with a 50/34 crank, an 11-34 cassette, the same dual 160mm rotors, and no power meter comes to 2,471 grams.
Like I said in the video, this presents a bit of a problem. Shimano is lighter but the SRAM power meter is 35 grams so that makes SRAM lighter.
The way I’ve decided to handle this is to compare the vision of the two brands. SRAM believes every groupset should have a power meter. Shimano isn’t quite there yet. With that in mind, that’s what I’ve spent time with and put on the scale.
In terms of what’s offered, I mention below that I don’t see this as a competitive advantage one way or the other. There’s tons of options for power meters on the Shimano side and I’ve gone with Look pedals. I could weigh the difference between the two pedals but that opens a whole can of worms. I’m not saying that 14 grams matters but for the systems I have on hand, I’m calling this a Shimano win.
Brakes +1 point SRAM
I’m going to bet that this one draws some hate but SRAM wins here. I’m not sure that was always true but with this latest version, SRAM has better brakes.
Obviously both will stop a bike just fine. The difference is that SRAM makes room for your fingers behind the levers and there’s better modulation with one or two fingers. You could argue that’s because SRAM is also catering to gravel bikes with only a single lever design, but are we really going to complain about better braking? Besides, Shimano already gets points for better hood shapes and mineral oil for brake fluid. Maybe you can’t have those without losing this but this is where I see it landing.
SRAM Red AXS vs Shimano Dura Ace — equally good
There’s a whole portion of the internet devoted to arguing about the relative shifting performance and/or gearing efficiency of these two. I don’t see it.
SRAM gearing pushes for a smaller front chainring and adds a 10-tooth cog in the rear. The idea is to keep you in the bigger ring more often. I’d love to tell you definitively one way or the other but, as discussed, Shimano doesn’t show that kind of detail. My feeling is that I’m running a similar setup on both systems and it’s pretty irrelevant overall.
Both systems also shift incredibly fast and are smooth. You can shift under load without worrying and I don’t find front derailleur performance noticeably different either way. I’ve run the previous SRAM Red AXS since 2019 and I’ve had it drop the chain maybe once with a front shift. This version is better according to SRAM so do what you will with that info.
I’m also calling it a draw for power meters. SRAM has them, Shimano basically doesn’t, but it doesn’t really matter. If you want a power meter, there are plenty of ways to add it to Shimano systems. The only time this matters is at the wholesale level where SRAM makes it easy for bike brands to include a power meter while Shimano doesn’t. That makes it far more likely a bike with SRAM includes the power meter but it doesn’t affect the performance once you have something.
Same deal with the bonus buttons. Neither are easy to push and both work about as well. Shimano comes programmed to change the screens on your computer while SRAM comes programmed as secondary shift buttons. You can switch the function of both.
One neat trick you could do with the SRAM bonus buttons is program them for the opposite function of the primary shift button. This is useful if you need to shift one handed (perhaps while filming). SRAM uses the right controls for harder and the left for easier. That means it takes two hands to shift both directions. I don’t find that a meaningful better or worse scenario than Shimano but if you want both functions available to one hand, the bonus buttons will accomplish that.
SRAM Red AXS vs Shimano Dura Ace — my choice
I hate making a definitive statement about this. Both are so incredibly good there’s no loser here. As you can see, there are seven details I find important to the experience of riding one vs the other. I assigned four points to SRAM and three to Shimano. That means SRAM already won but it’s a little less straightforward than that.
I mean sure, I think the SRAM software is better but does that actually matter? Maybe but maybe not. Also maybe you are deeply invested in the concept of inefficiency from a 10-tooth cassette cog and a smaller chainring. Or maybe you want a third party crank and there’s not one made in the SRAM chainring sizes (this is common). You might also hate the SRAM buttons and that works. It could easily go either way.
All that said, I choose SRAM. I say this because of the clutch and the batteries. My roads are rough and I find it annoying when the chain bounces around. I found it especially annoying when the chain came off the Shimano bike and scraped up the crankset.
On the batteries side of things, I like the flexibility of SRAM. I rarely use the app to check the battery level of either system. Instead I just charge it every so often. With Shimano I have to get a battery pack and attach it to the bike. With SRAM I have extra batteries so I swap one on and throw the used one on the charger. I’ve also lent out a battery when someone forgot a battery at home on a ride. That’s definitely easier.
It should also be noted that Shimano Dura-Ace is older. Shimano will have a new system sooner and it won’t take much to come out on top.
Look 795 Blade RS – The Shimano Dura-Ace build
This bike is the build with the longest history of the two. Look is a fascinating brand that stands apart from bigger names. If you ride a Look it’s because you sought it out and I appreciate that quality in everything I use.
I had the previous generation of the Look 795 Blade RS and an airline cracked it. I was able to replace it after the new generation came out and I had my hands on it very early on. So early that I have the black colorway because the iconic edition wasn’t yet available. No one should own a Look without the Mondrian colors but thankfully the black has it.
In terms of the frameset what’s important to understand is the Look philosophy and the fit. The first part of that is the Look philosophy of building a race bike. Ostensibly this is an aero frameset but it’s missing the usual aero tricks like a super deep headtube, wide fork blades, or a shielded thru axle. There’s also reports of it being somewhat aerodynamically slow compared to the competition.
I haven’t personally aero tested this bike but I’m also not surprised. I asked Romain Simon, Bike Product Manager for Look, about the missing aero tricks and his response was, “Aerodynamic gains of a shielded axle are anecdotal when weight and resistance could be impacted. Keeping our development simple with a ‘classic’ thru-axle has benefits: standard parts, easy maintenance, and wheel replacement for example. 795 Blade RS is our race bike, aerodynamics is important, but efficiency prevails in every choice.”
Then there’s the ride position. The Look handlebars are not a one-piece design but they do appear to be and both the stem and the bars are proprietary. This matters because not only is the headtube short at 136.7 mm for a size medium but the shape of the handlebar makes it feel natural to position the controls forward and low.
Over and over I go back to it wondering why I put it there but I only set it up once. The second time a friend placed the controls and he did the same. Far out and low seems to make sense when you are placing the controls and that’s also a highly aero position. The current setup isn’t awesome for long distances but it’s amazing for getting into an aero position on the hoods.
Given that this is a modern integrated frame, the seat post is also part of the frameset along with the bar and stem. That leaves only a limited amount of details for the rest of the build. I have a CeramicSpeed bottom bracket hidden away behind the cranks, I’m running Silca Nastro Cuscino bar tape at the front, and the saddle I’ve chosen is the Selle San Marco Shortfit 2.0 3D. This bike gets the Carbon FX version just to save a bit of weight.
For the wheels, I’ve swapped things around here and there. I had a picture of everything looking gorgeous with Roval wheels earlier this year but, as with the saddle, I’ve chosen to save weight with one of my favorite sets of wheels, the CADEX 50 Ultra Disc Tubeless. I love the feel of Cadex wheels and it’s hard to argue with 1349g for a 50mm depth. Both aero and light are the name of the game here. I’ve paired them with Cadex tires and there’s a set of Cadex bottle cages, which marry very well with the tube shapes, to pull in the last bit of Cadex goodness on this bike.
Hope is handling braking duties as I’ve swapped the Shimano calipers for Hope RX4+ four-piston anodized gorgeousness. That’s not a statement of malcontent in relation to the Shimano calipers. Shimano brakes are fine but four-piston is always going to offer more power and, more importantly, the Hope RX4+ calipers look great.
To handle both meter duties, and my connection to the bike, I’ve got a set of Look Keo Blade Power Dual pedals. Shimano isn’t keen on discussing power meters, they’ve disappeared from the site, but the brand does make great pedals. I opted for Look compatible pedals because that’s my preference. Besides, I’m pretty sure if you ride a Look frame, matching pedals are required.
Bianchi Specialissima – The SRAM RED AXS build
Given the timing of the 2024 SRAM Red AXS release, this is by necessity the newer build. There’s also no story of cracked frames and a long history of riding previous generations. Over the years whenever I’ve thought about brands I dreamed of owning, it was Bianchi. Despite never having a strong connection to pro racing, there’s always been something special to me about the iconic Celeste. Now I’m lucky enough to have one in my stable of bikes.
You can read more details about this bike in my Bianchi Specialissima review but I’ve got a Pro version. For me the less expensive frame is a better choice with its inclusion of Bianchi countervail tech. Besides that, I’ve worked on it a bit since the review but, notably, what I haven’t done is actually change it that much. What I mean is that in my initial review one of the things I wanted to change was the handlebar setup. Turns out that’s easier said than done.
I honestly had no idea the can of worms I was diving into here and it’s probably worth a full article on its own. I wanted a 110×38 one-piece bar and stem but there’s nothing out there right now. Bianchi doesn’t make a 38, Cadex doesn’t have a top cap solution, Deda Elementi doesn’t have any stock, Enve has choices but the top cap is still an issue, and FSA/Vision also lacks a 38cm bar width. What I landed on in the end is a Vision Metron 5D ACR in a 110×40 size but it’s not installed.
I landed on that bar and stem because I knew that FSA (Vision) often worked closely with Bianchi. I’d seen a number of FSA show bikes built on Bianchi frames and the 40 cm width isn’t actually 40 cm. The way that FSA measures bars means the 40 cm is actually a 39 so I called it good. Then FSA didn’t have any stock on the top cap to match the frame. That means despite a ton of behind the scenes work, the FSA bar and stem is currently sitting in my stack of parts waiting for a future install. A bar and stem combo of 110×38 shouldn’t be a unique need or hard to find but here we are.
That leaves me with the stock 110×40 Bianchi bars and they really aren’t bad. I never quite solved the steerer tube bolt cover issue though I did eventually pick up a replacement gasket for the seat post (check the review for the info on both). If Bianchi offered a 110×38 I probably wouldn’t bother looking elsewhere. For now, I’ve wrapped these bars in the same Silca tape as the Look and the saddle is a Prologo Nago R4 PAS 3DMSS. Bottle cages, again to match the design of the bike, are Elite Vico carbon units.
I actually showed a sneak peak of the wheels when I published the bike review. I had one picture of the Black Inc Five wheels in that article but once the review was done, they never left the frame again. I love these wheels and I love the way they compliment the angles of the Bianchi frame. Beyond the visuals, the stiffness of these wheels also compliments the feel of the frame. Solid spoke wheels are inherently aerodynamic but the Black Inc Five wheels climb like nothing else. For rubber I’ve gone with Pirelli PZero Race TLR RS.
For pedals on this bike, I stuck to SRAM. The Time XPro 12SL pedals (or Time in general) are actually my favorite pedals. The only reason I don’t standardize on them is because there’s limited options. No power meters and no third party compatibility makes it tough to choose Time across a wide range of needs. On the other hand, for a single bike with a SRAM build the power meter is in the crank and these make perfect sense.
I also recently added the Quarq TyreWiz pressure sensors and in theory I’m a huge fan. I’ve had these kicking around my office for a long time and you might notice they are the first gen version. SRAM fixed this design for Quark TyreWiz version 2.0 so long term I’ll either upgrade or try to make it a little less ridiculous looking with a shorter valve stem. Whatever I end up doing, I kept them for this article as it’s a useful product that SRAM offers as part of the ecosystem.
SRAM Red AXS vs Shimano Dura-Ace Gallery
