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10-4
11-24-2013, 04:46 PM
Looking at a 6870 Ultegra Di2 setup, but I already have a set of 6770 shifters. Did anything change from 6770 to 6870 in the shifters?

They are both E-Tube, so will work fine, but are there any changes I'd be missing out on?
oldpotatoe
11-24-2013, 04:56 PM
Looking at a 6870 Ultegra Di2 setup, but I already have a set of 6770 shifters. Did anything change from 6770 to 6870 in the shifters?

They are both E-Tube, so will work fine, but are there any changes I'd be missing out on?

You can program 6870 to 10s..not sure you can program 6770 to 11s..plus need a RD..for 11s.

Also not sure 6870 will talk to otherwise 6770 stuff..
10-4
11-24-2013, 09:41 PM
You can program 6870 to 10s..not sure you can program 6770 to 11s..plus need a RD..for 11s.

Also not sure 6870 will talk to otherwise 6770 stuff..

Not sure either. I rode 6770 shifters to 9070 RD/FD and everything worked perfectly in 11sp.

I'm looking for 11sp since everything else is 11. Seems I should just run my 6770 shifters with 6870 RD/FD
oldpotatoe
11-25-2013, 08:04 AM
Not sure either. I rode 6770 shifters to 9070 RD/FD and everything worked perfectly in 11sp.

I'm looking for 11sp since everything else is 11. Seems I should just run my 6770 shifters with 6870 RD/FD

But you 'told' the shifters to be 11s, right? I wasn't aware that the interface for 6770 had the USB gizmo to talk to a 'puter but I speak EPS better than Di2.

Or plug in 11s rear derailleur and it 'knows'?

"How do it know?"
10-4
11-25-2013, 08:24 AM
But you 'told' the shifters to be 11s, right? I wasn't aware that the interface for 6770 had the USB gizmo to talk to a 'puter but I speak EPS better than Di2.

Or plug in 11s rear derailleur and it 'knows'?

"How do it know?"

The RD is the part that knows how many gears it can shift. Shifters just tell RD "move up" or "move down", they don't "count".

6770 can use any of the E-Tube junction boxes, I ran the 3-port one under my stem. Plugged that into my laptop and did firmware updates.

I thought I read that you could tell a 9070 RD to be 10-speed, but never tried. Maybe I'll plug mine in tonight just to see.
oldpotatoe
11-25-2013, 10:40 AM
The RD is the part that knows how many gears it can shift. Shifters just tell RD "move up" or "move down", they don't "count".

6770 can use any of the E-Tube junction boxes, I ran the 3-port one under my stem. Plugged that into my laptop and did firmware updates.

I thought I read that you could tell a 9070 RD to be 10-speed, but never tried. Maybe I'll plug mine in tonight just to see.

You can, just rode with a guy who had this very set up, but can't make 7970/6770 11s w/o a 11s rear der. Confusing, IMHO. Seems easier to just be 11s. Lack of ability to put 11s cogs on 10s shimano FH might have something to do with it.
10-4
11-25-2013, 11:01 AM
7970 isn't E-Tube, so that won't happen without a hack.

I kind of like it. Any 11sp RD makes your whole system 11sp. Would be nice if 6870 was able to be programmed to 10sp. We'll see soon enough.
oldpotatoe
11-25-2013, 05:57 PM
[QUOTE=10-4;1457901]7970 isn't E-Tube, so that won't happen without a hack.

I kind of like it. Any 11sp RD makes your whole system 11sp. Would be nice if 6870 was able to be programmed to 10sp. We'll see soon enough.[/


That's right, first gen Di2, like 7400/7410, unique.

But you can program 6870 or 9070 to be 10s