Electronic & Hydraulic Shifting (Di2, Ui2, customisations)

I have the original flat mount calipers. Can I use the DA levers with my existing calipers?

They'll probably work, but no clue on the performance..

As far as I know there are no standards on pressure and stroke. So you could end up with totally the wrong lever feel and power modulation.

And the DA levers have a new bleeding system. No idea if it's compatible with the old calipers

Thanks. I'll keep digging.

Do you know what the new bleeding system involves?

nope, sorry.. all I know is it's called "one-way bleed"

Sounds like me and Uxbridge Road...

http://www.epicbleedsolutions.com/blog/how-to-bleed-new-shimano-brakes/

That's just unnecessarily complicated. Not sure there was ever an issue with the funnel. R785's bleed spot on like that.

All brake bleeding is a ball ache to me. I can't even tell the difference between process. Pump shit in one end wait for it at the other. What's the actual diff?

MAGNETS!

Honestly not much, just a different way of passing fluid through the system to eliminate air. Only thing I can see that they might have changed between last gen and this gen is maybe the hose sizing if they're varying between pressure and volume.
I'd hazard a guess and say pressure since the reservoir is going to be tiny under those hoods.

The calipers don't see to show anything out of the Shimano ordinary. Threaded hose instead of banjo, and a 7mm bleed port.

If they have the blips at the top of the hoods, I imagine the bleed port screw is going to be directly between thumb and index finger. I can't see any easier method to do so then with the funnel, which is as @Jaap said, a one way bleed.
meh!

I know it's superficial and there's definitely no specific details about bleeding, pressure, cables and the like, but the Shimano compatibility list (http://productinfo.shimano.com/download/pdf/com/2.7/en) does indicate compatibility between 9170 levers and older generation calipers (this is an answer I'm interested in as well)

nice find! didn't know such a chart existed, thanks!

Got all my new di2 stuff today.

Hooks up fine but it looks like, even with a firmware update, 6770 front and rear derailleurs are not synchro shift compatible yet.

Means I need another RM600 to use it properly.

or go 1x ;)

That would make sense but then I've got a chainset and and fd to get rid of as well as the faff of choosing a new chainset with the right ratio etc.

Or I could buy a switch for £60

And what happens if a month later, a firmware update allows synchro shift with 6770 derailleurs?

I only seem to find sw-r600-r (right hand). Did you buy two rights, or if not, where did you buy your left switch?

Unlikely, Possible that the synchro shift code is only written with 11s in mind.

I'll have two rights. The app allows you to change the function to make it work.

What's the point of synchro shift? Seems like the Di2 equivalent of an auto gearbox?

To only have one button unit is the only reason I was interested.

Synchro will never come to 6770, I doubt it if it will come to 6870 (as a new trickled down from 9170 ultegra must be in pipeline) .. even though its e-tube shimano is weirdly old school in the way they roll out and restrict these updates.

Etube app updated today... Confirmed 6870 synchro shift / not for 6770.

Meanwhile, I've changed mine to 1x10.

Maybe it's me.. But the few times I shift my front derailleur I hit the wrong button a lot of times. So synchro shift does sound nice

I have never shifted the wrong way on my Di2, even in gloves. I have quite dainty fingers though.

I can't be bothered to trawl back up the thread so very quickly: is the new bar end junction box compatible with 6870?

Iirc yes