SRAM AXS or Shimano Di2 hydro?

[muz]

I got a new, 2019 S-Works Roubaix frameset at a good price. Now I need to decide on the groupset. The obvious choice would be Ultegra 8070 Di2 with hydraulic brakes. But I am tempted by Red AXS or Dura Ace 9170.

I know Shimano stuff just works, and Ultegra gives me lower gearing choices and cheaper price at a small weight penalty. I like to tinker, so Di2 cable installation doesn't bother me.

AXS does look good on paper, but it seems it is not compatible with anything. I do have a Zipp wheelset that will take an XDR driver, so at least I won't need a wheelset. I can't even use other cranksets, it seems the SRAM flat top chain is not compatible with non-SRAM cranks.

So, any advice? Is there even any reason I should be considering AXS? How about Dura Ace?

[FlashUNC]

SRAM chains do work with other cranks, but their cranks are pretty excellent.

I'd say AXS myself.

[yinzerniner]

I got a new, 2019 S-Works Roubaix frameset at a good price. Now I need to decide on the groupset. The obvious choice would be Ultegra 8070 Di2 with hydraulic brakes. But I am tempted by Red AXS or Dura Ace 9170.

I know Shimano stuff just works, and Ultegra gives me lower gearing choices and cheaper price at a small weight penalty. I like to tinker, so Di2 cable installation doesn't bother me.

AXS does look good on paper, but it seems it is not compatible with anything. I do have a Zipp wheelset that will take an XDR driver, so at least I won't need a wheelset. I can't even use other cranksets, it seems the SRAM flat top chain is not compatible with non-SRAM cranks.

So, any advice? Is there even any reason I should be considering AXS? How about Dura Ace?

If you're sticking to mostly road riding, and Di2 install doesn't bother you then I'd go that route. Stick with Ultegra GRX just about everything, maybe upgrade the crankset if possible to a nice PM. The new GRX Di2 shifters are the best on the market in terms of ergonomics, although their looks polarize.

There are a few aftermarket 2x chainrings that are supposed to work with the Flat Top chain of AXS, but they're either very pricey or proprietary.

[morrisericd]

Here's my take. I currently have the current generation Di2 on my road bike and AXS on my gravel bike. I also had eTap on a previous gravel bike.

Shimano is not sexy, but it works (edit: at least the shifting anyway) and you never think about it. Lots of cross compatibility with other cassettes, chains, etc. XD and XDR piss me off. No rational explanation except when I went to swap out my driver for a Chris King one they wanted to charge me $300. No thanks. The Red XDR cassette is a marvel of engineering though. Shimano road disc brakes suck. I have them on this road bike and my cross bike. The pads wear out super fast and the shifters always seem to have some sort of issue. I've had several shifters recalled when they wouldn't reliably hold fluid. During cross season, when it's muddy (like - always in the Northeast), I seem to be swapping out $25/ wheel pads every race. It's like those ink jet printers you get for $100, and the ink costs $500!

AXS is super cool and really leading edge and all that. I can't stand the gaps in their 12 speed cassettes. I ride both bikes regularly and the dura ace cassette (11-30) is perfect. I have both the 10-28 and the 10-33 (road and gravel wheels) and the gaps are just weird. On the 10-33, they are too spaced out. On the 10-28, they are better but almost too close. I started out with a 1x setup and the low end was fine, but the bigger gears weren't big enough and had too many gaps. Now I'm on a 2x setup and it's good, but not as good as my Di2. AXS brakes rule. So good. Great modulation, great stopping power.

There you go. Random thoughts and no conclusion.

[weiwentg]

AXS gets you 12 cogs, and right now, Dura Ace and Ultegra Di2 both get you 11.

Also, if you're set on getting a dual-sided (or total power) crank power meter, then current Shimano cranks should arguably be out of the running (https://gplama.com/2019/06/29/shimano-crankset-power-meters/). This applies to any power meter mounted to the drive side of current generation Shimano cranks. Non-drive side appears fine.

If you care about this sort of thing, Dura Ace appears to be the lowest-friction chain on the market, and unfortunately SRAM's 12s chains seem to be 1-2 watts behind DA (https://cyclingtips.com/2019/12/the-best-bicycle-chain-durability-and-efficiency-tested/). Plus additional drivetrain friction from SRAM's smaller chainrings and cogs. This one is really splitting hairs, though.

[9tubes]

Ride both and see which brake hoods you like better. It's not that one has hoods better than the other in the objective sense. It's more of a blondes vs brunettes thing. Or what you're used to. There are many newer riders who have never ridden anything other than Shimano for more than 50 miles.

Also, note which hoods have more forward extension if that is important to you.

Shifting on both is flawless. I suggest looking at the gear pattern to see which one better suits your needs. For me, eTap 12 has zero benefit over eTap 11 but that's just the speeds and where I ride.