I'm looking to install a SRAM etap drivetrain with 50/34 Red 22 crankset. I'm currently running 10x with a SRAM PG-1070 11-26. So my initial thought was just go with a PG-1170. That gives me the 16 though I don't know that I've been missing it. Then I thought maybe look at Shimano too, and I was thinking maybe the Ultegra CS-6800 is an option? I would be looking at the 11-28 which seems like it gives me another option on the big end, still no 16 but again I'm not sure I need it. Does the Ultegra work with SRAM 11x system? If it makes a difference I run KMC chains and expect to continue (X11 chain). I have no interest in Shimano chains.

scott s.
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Either would work fine. sram would say their ones would work better. i personally like shimano cassettes but the new xg cassettes from sram are great but pricey. id say go for which ever you like more.I am jealous that your able to think about getting etap tho. hope this helps and good luck on the decision.

It's hard enough justifying etap but then to also go for an xg cassette -- that's just too much. I'm not quite ready to pull the trigger, so I can mull it over for a while.

scott s.
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The deraillers won't care which cassettes you use. One of the nice things about electric shift is its positivity, so miniscule differences in cassette
ergonomics are even more muted. Go with which ever one you can afford and gives you the gearing you want. 6800 will work fine with eTap.
You get to help SRAM mitigate their development expenses by being an early adopter, so feel good about that.

Thanks. I'm guessing it will be quite a while before SRAM or dealers discount eTap. Maybe more likely for a Force level version to show up.

scott s.
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I don't yet have eTap, but Shimano cassettes have worked find, perhaps better the SRAM cassettes, with my mech Red groups.

It is a bit surprising that UK online shops can sell Ultegra groupo for $5-600 mechanical and $1100 for Di2 but complete bikes have $1500 to $2k premium for name brand
bikes at retail for Di2 variants. One instance where upgrade of a suitable frameset (ie internal routing) makes more sense than a complete bike (assuming wheels of course).
Judging from SRAM pricing over the past few years etap will still be well above Di2 for a long time.