I think it's because they basically took the old rim brake levers and retrofitted the new etube wiring to them. I.e. they did not do any new development there. Adding wireless would have required redesigning the levers and they didn't think it was worth it.

i have not put a SRAM wheel in this bike. yet. but i intend to. this will cause shimano folks to repeatedly bang their heads on the table, but this is a question that is going to get repeatedly asked, so, i will test this just to see how things work. the one and, really, only one reason i can think to do this is to get a 10t cog, and perhaps just SRAM's much wider available gearing, onto a dura ace 12sp bike. remember, these new bikes only allow for a 34t cog, so, if you put, say, a 10-36 on there you're technically exceeding shimano's capacity for this group.

beyond that, if you can put a shimano body driver on a hub, you can ride said wheel with these groupsets.

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Dan Empfield
aka Slowman

So for a TT bike, the only thing that really changes is 12 speed. But existing tt shifters can be re-used with a new adaptor.

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I'm tracking 100%. Like many others, I'm mostly interested in gravelish implications. There's also a few other things to worry about (swapping in a non-SRAM cassette) like the flat top chain (I would be coming from AXS XPLR), the pulleys in the RD, etc. with the weird new shape of the chain specific to all of the non-Eagle AXS stuff. I have a few extra wheels for cyclocross where a 10 cog would be superfluous and I don't care what's on my trainer. I would probably leave the 11 speed cassette on if it work well enough in the few gears I switch between in ERG mode. If an 11-34 cassette managed to work as-is in the AXS XPLR drivetrain, I would be pretty happy though. The Rival AXS cassette and XDR freehub for my wheels are all over $200 and the Force cassettes add another $60 to that. That really adds up over a handful of wheelsets.

I'm still wrapping my head around what internet strangers experience mixing in campy or eagle chains within the AXS stuff. After years of experimenting, there's a lot more cross compatibility than intended. I look forward to hearing more of your experience.

I'm missing something; what is the difference between an MTB brake rotor and a road rotor? They are both round flat steel disks mounted to the hub that the calipers rub on. Admittedly the usage is different between a road brake and a mtb brake, but not that different.

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salmon - not because I'm a fish

So for TT, you still need to run wires to a junction box in the front end?

In true shimano fashion it's an all or nothing upgrade to sell you more parts and make the last generation obsolete. They tweaked the wire size and locked up the firmware so you can't use those last gen di2 shifters and brakes with just a new set of derailleurs, chain, and cassette if you want to upgrade from 11s to 12s. This is significant because you'll have to dole out an additional $1700 for those shift levers. I can see people buying new bikes with this already equipped but who's going to throw away their all of their 11 speed components and spend $4500 to add a gear and slightly better shifting/braking performance?! Disappointed but not surprised.

nothing. no difference. shimano found they could not build a road rotor that exceeded the utility of the MTB rotor. so, it's the MTB rotor. in my writeup on these groupsets my bird's eye view take on these groupsets is that shimano just kept finding that it's offroad components or tech were better for road than what they were making for road, so they largely repurposed offroad tech for road. they did that for brakes, for cassettes, chain rings, and so on. i think handlebar companies have been doing the same thing (repurposing gravel bar ideas toward road bars); and wheel companies, purposing MTB and gravel tech toward road, with tubless, hookless, and wide inner bead distances.

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Dan Empfield
aka Slowman

Surprised the short crank lovers here aren't frothing over the new 160mm options.

Also on the cranks, surprised Shimano hasn't appeared to have changed from the hollowtech bonded ready-to-debond-at-a-moments-notice design..

Nitpick - 50 was for Di2 and 20 was for hydraulic. (eg mechanical shift, hydraulic brake shifters were 9120)

Add them together and you get 70...

i'll buy that reasoning. sounds plausible and historically defensible. but there are some hiccups to that. the new brake caliper is BR-9270. that ought to just be BR-9220 using your reasoning. same thing wiith the new Dura Ace wheels released today (my story on these upcoming). a sample model name is WH-R9270-C36-TL. as you may guess, this is a tubeless C36 built for hydraulic brakes. even if you argue that the brake calipers above are sorta kinda part of an electronic shift system, you can't really argue this for the wheels. all the new disc brake wheels are 9270.

here's a real weird one for you. as i mentioned in the writeup, there is a rim brake option in this groupset. as i understand it, the rim brake caliper has as part of its model name 9250. how did that happen?

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Dan Empfield
aka Slowman

For those of us on rim brake bikes that may want to upgrade? Although I'm not sure about the spacing on the hub to facilitate that.

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Washed up footy player turned Triathlete.

Well they still seem to be using plenty of 50s and 70s in the parts numbering, I guess the lack of 20s indicates the death of mechanical? Or maybe they just used 70 on parts that are compatible with Di2, such as brakes and wheels?

that's the point i'm making, i think. 70 is hydraulic, 50 is electronic, and if it's a hydraulic part that has no real attachment to electronic, it's still 70 (not 20). mind, this has changed some over the years. it used to be 70 was electronic, way back in the beginning of electronic shifting. but that got changed in maybe 2012 or so, i don't know, in any case it's not that way now.

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Dan Empfield
aka Slowman

If that is true, that is very unfortunate.

I can see the idea of no dura ace mechanical, but for ultegra as well? That seems to be a very poor decision.

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Advanced Aero TopTube Storage for Road, Gravel, & Tri...ZeroSlip & Direct-mount, made in the USA.
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So with the TT shifter adapter the existing 9100/8000 shifters should work with the 12 speed drive train too then?

Correct

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Yes.

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Great now I just need to figure out if the calipers will work with 8000/9100, then I can get a slightly cheaper upgrade to 12 speed and keep the normal reach hoods.

However I will gain 70g with the cassette…. Shimano cassettes are just so heavy

Why didn't Shimano get ahead of the curve and just bring out a 13 speed groupset? You know this is going to go in the same direction as men's shavers-just when you thought 3 blades was rediculous they went up to 6 blades...

Hey Dan,

I’m seeing some conflicting information on shimano’s website. Are ST-R9180 compatible with BR-R9270 calipers? Shimanos compatibility matrix says no but the the lineup chart shows they are.

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Which lineup chart says they are?

i suspect they are. shimano shows that the in-line TT/tri levers/shifters are compatible with 9200, and the only caliper in that groupset is the 9270. i think you're fine. same with the new ultegra calipers.

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Dan Empfield
aka Slowman

Shimano rotors have an aluminum core and cooling fins.