Compatibility 6870/6770 DI2

[Bentley]

Are these compatible? Specifically, 6770 Brifters and 6860 FD/RD.

Thanks

Ray

[shovelhd]

Originally Posted by Bentley

Are these compatible? Specifically, 6770 Brifters and 6860 FD/RD.

Thanks

Ray

Only with the original 6770 STI firmware. Once you upgrade, they're no longer compatible.

[dem]

Assuming you mean STI-6770 shifters and both RD-6870/FD-6870, absolutely yes (this is literally what is running on my Parlee.)

What Shovel refers to is using STI-6770 with FD-6770/RD-6870 combo. There's no technical reason why the 10 speed FD can't work as 11 speed, but in typical Shimano fashion they obsoleted this in a version of the firmware.

The 10/11 speed "intelligence" is based on the rear derailler, but the FD is dumb. For a brief period, you could just buy the rear 11 speed derailler and be good to go.. but as soon as you updated the firmware, it would stop working.

Now don't get me started on why Shimano won't let you mix and match road/mountain Di2!

[Bentley]

Originally Posted by dem

Assuming you mean STI-6770 shifters and both RD-6870/FD-6870, absolutely yes (this is literally what is running on my Parlee.)

What Shovel refers to is using STI-6770 with FD-6770/RD-6870 combo. There's no technical reason why the 10 speed FD can't work as 11 speed, but in typical Shimano fashion they obsoleted this in a version of the firmware.

The 10/11 speed "intelligence" is based on the rear derailler, but the FD is dumb. For a brief period, you could just buy the rear 11 speed derailler and be good to go.. but as soon as you updated the firmware, it would stop working.

Now don't get me started on why Shimano won't let you mix and match road/mountain Di2!

So 6770 Brifters with 6870 Derailleurs work ok even with updated firmware?

Ray

[Zee]

To be clear, you all are suggesting simply getting a 6860 plugged into a 6770 system and it will start acting like a 11 speed; but if you update the firmware, it needs a matching front mech?

Not to high jack, but can 6770's use MTB derallieurs?

[dem]

Originally Posted by Bentley

So 6770 Brifters with 6870 Derailleurs work ok even with updated firmware?

Yes. (assuming you mean 6870, since I don't see any 6860)

Depending on the age of your 6770 group, it may just plug in and go with no firmware update.

Mine was so old I had to flash it to get it to recognize the RD-6870 at all, so I am running the latest Di2 firmware.

[dem]

Originally Posted by Zee

To be clear, you all are suggesting simply getting a 6860 plugged into a 6770 system and it will start acting like a 11 speed; but if you update the firmware, it needs a matching front mech?

Not to high jack, but can 6770's use MTB derallieurs?

1) Yes, if you're in the sweet spot of 6770 firmware AFTER Shimano released the 11 speed and BEFORE they changed the firmware to disable it. It is crazy.

2) Same problem, you can use road Di2 shifters with Di2 MTB FD/RD.. but again they have to match. Which is annoying if you want to run a set of big road double rings + big MTB cassette.

[Bentley]

Originally Posted by dem

Yes. (assuming you mean 6870, since I don't see any 6860)

Depending on the age of your 6770 group, it may just plug in and go with no firmware update.

Mine was so old I had to flash it to get it to recognize the RD-6870 at all, so I am running the latest Di2 firmware.

Not sure where the 6860 comment came from??

[dem]

Originally Posted by Bentley

Not sure where the 6860 comment came from??

Sorry, was reading multiple replies - some posts above referred to 6860.

Di2 stuff is confusing enough so I wanted to be specific.

[Zee]

Originally Posted by dem

1) Yes, if you're in the sweet spot of 6770 firmware AFTER Shimano released the 11 speed and BEFORE they changed the firmware to disable it. It is crazy.

2) Same problem, you can use road Di2 shifters with Di2 MTB FD/RD.. but again they have to match. Which is annoying if you want to run a set of big road double rings + big MTB cassette.

I think the group on WW has some of that stuff those specific firmwares for email...

Originally Posted by Bentley

Not sure where the 6860 comment came from??

I'm partially responsible and 100% blame the iPhone keyboard.

[zank]

Any di2 shifter/switch (except for st-7970) will work with any e-tube derailleur system. You will be fine with st-6770 levers and rd-6870 and fd-6870 derailleurs. You can't mix 10 speed and 11 speed road derailleurs (fd-6870 and rd-6770 for example) and you can't mix road and mtb derailleurs (fd-6870 and rd-m8050 for example).