SRAM Force AXS vs Shimano Ultegra Di2

Yes, you are indeed missing something. I initially posted this (added emphasis):

So we were talking about going the Shimano groupset route, but replacing the Shimano cranks for either SRAM + Quarq cranks for Rotor + powermeter cranks. You wouldn’t want to use SRAM chainrings in that case, i. e. the (very much real) issue you point to is not relevant here.

@mhandwerk added to that by pointing out that even though officially Quarq’s DFour power meter (Shimano mounting points version) is only compatible with 11-speed chainrings, 12-speed Shimano chainrings (which the OP would use) work just fine.

I have seen many people go this route: they like the accuracy and reliability of Quarq power meters, the lightness of SRAM cranks and how Shimano chainrings shift. This package combines the best of all worlds for them.

That works with flat top 12s?

I have both group sets, on two different bikes, both 12-speed. I like the Shimano better. Unlike almost everyone above, I find that Shimano shifting is more intuitive to me. I’ve ridden bikes for fun and competitively for over 50 years, and I’m afraid I’m wedded to “left hand = FD, right hand = RD”. That being said, I also find the Shimano front shifts to be noticeably faster. Both of my group sets use the Shimano or SRAM crank, respectively, and I have PMs on both; but for the Shimano, I went OEM with a Stages Left side only PM. (I have PMs on a number of my bikes, and all are “accurate” in that they vary little from the “base”… which I determined by comparing readings between each of them and using a Kicker as comparative. Are they really accurate? I have NFI; but for my purposes, all the bikes give close enough readings for training.) I’ve used Wipperman chains in the past; there is no Wipperman equivalent for the SRAM Flattop chain, so you’re stuck with SRAM’s chain. As far as efficiency, I’m not sure for most of us the marginal gain is significant.

One thing I have noticed with 12-speed (both groups) is a distinct propensity for more dropped chains. I rarely drop a chain in 11-speed or lesser-speed groups, but it occurs much more frequently with 12-speed. With the Shimano bike, I “fixed” it by adjusting the FD (done on my phone, which was very cool!), but I will admit to a slight bit of chain rub in certain extreme cross-chained gears. With the SRAM bike, I had to get a chain catcher, with which apparently early versions of Red came. Lots on the internet about this, and that SRAM is “finicky” when it comes to having the FD adjustment correct. Of course, this could be user error as well. YMMV.

FWIW, I bought the SRAM bike first because it was on sale and I got a really good deal. But with the Shimano bike, I had a choice and willfully decided to get Shimano even though it was slightly more expensive. But too be honest… the pros seem to be able to use anything with little problem.


While riding my Sram 12s yesterday I remember another flaw and I think shimano 11s shifting seemed a lot better. I have a few gears that are clunky on my Red and Rival stuff and that never happened with Shamino. I confirmed with others that they have the same issue.

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Both Sram and Shimano groups are great, though I haven’t used the new 12spd Shimano R8150 only the 11spd di2 version. I recently changed to Sram Force AXS. I have to say I like Shimano better. I prefer the ergonomics and shifting platform of the Shimano, and I feel like it shifts better. Sram is a bit easier to set up, but thats a one time thing and the potential gear ratios are slightly better with Sram. I found the Shimano battery to last longer between charges. I like the Quarq power meter it works great, as does my Rotor I Have no experience with the 4iiii system. Sram does rely on a 10 tooth cog to achieve a taller/bigger gear which does result in more chain friction due to the tight turn. I don’t have many wide open descent so its not really an issue for me.

i like the gearing options of sram, but in the end i’d pick shimano because of the hood buttons that helps control my garmin.

not really essential, but being able to switch my screen to the map when i’m on a descent have been very helpful for me in making sure i don’t make a wrong turn (which has happened more than once)

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Is that just “feel” akin to the exhaust note of a car or actual functionality? Both simply work in my experience. In my experience, Shimano can feel smoother, but can also be noticeably crunchier if I catch it off guard. SRAM’s shifts stay more consistent. In my opinion that’s more of a shift feel thing. (Subjective criteria are totally fine, just saying I find this more of a subjective thing.)

For reference, I have tried 11-speed Ultegra, 105/Ultegra mix and various 11-speed Ultegra Di2, DuraAce Di2 on various drop bar bikes, and have ridden XT and now 1x11 XTR on my mountain bikes.

I would love a cassette with the smallest cog having 11 tooths. :confused:

No, there is a noticeably clunkier shift. I can try to capture it, but both of sram bikes have this issue. My review with other anal retentive functioning people have confirmed they notice it also.


same here, and other local riders have the same issue. One specific gear near the middle of the cassette.


You can. Go to Rotor’s website and order one of their 12-speed cassettes.

To some it is clunkier, to others sportier. In the end, it is simply a different feel with no impact on functionality. I totally get that you have a preference, though.

E. g. SRAM shifters tend to have a more precisely defined trigger point whereas Shimano shifters tend to be smoother, but more vaguely defined. And Shimano’s Di2 shift buttons feel super cheap in comparison to SRAM Force shifter’s buttons. I’m a mechanical keyboard aficionado, so I notice these things. (Fellow anal retentive individual here :wave: :grin:)

Are we talking about a clunky gear change or something wrong with the shifting? The latter is not a SRAM thing, at least not exclusively. With my Shimano mechanical drivetrains I’d always have one or two loud or reluctant gears. With SRAM I only have an issue with my most-worn cog on my trainer (I should replace the cassette).


Thats the one.

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In my case, sometimes it skips over two, and then back one. Sometimes it doesn’t want to shift into gear. Sometimes it smoothly shifts into that gear. Annoying.

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I do feel like it has a delay when it determines to make that shift also. At first I thought it was just a rival issue, but it happens on my Red also.


software issue.

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I run Ultegra 11sp di2 with a SRAM cassette most of the time. I also have a loud “clunk” shift somewhere in the middle. I think it’s just the cassette gaps.

I got the 11-28 SRAM cassette because I wanted the 16t cog that the Shimano one lacks. So that means, the steps on the SRAM cassette are 25 → 22 → 19 while Shimano has 25 → 23 → 21 → 19.

My money is that the “clunk” comes from the bigger steps in that range on the SRAM cassette.

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I’ve had that shifting hesitation / mis-step / it-just-works game of roulette on 10-33 (Red) and 10-36 (Force) SRAM AXS 12-speed cassettes. With Force and Red derailleurs. Friend at LBS has it too and called SRAM and they claimed ‘working on a software fix’ but that was over a year ago.


For the dzero (5-bolt), the answer appears to be using Praxis or WolfTooth chainrings, who make 12-speed compatible rings. But also, some folks report OK performance using 11-speed SRAM/Shimano chainrings on 12-speed Shimano.

Yeap and it has SRAM, lol.

Is this like once per ride or twenty times per ride? If you were doing it over and had the choice of Shimano over Etap, would you go Shimano?