Another di2 upgrade thread. 6770 to 6870.
05-30-16, 01:43 PM
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Another di2 upgrade thread. 6770 to 6870.
TLDR; Can i use 6770 shifters with matched 6870 derailleurs? Can i use 11-28 cassette, being that i have 53x39 chain rings on my crank, with a short cage rear derailleur?
In lieu of an accident Saturday, I am looking to replace my rear derailleur. Thus I have now found out firsthand how impossible it is to find new stock 6770 parts.This is making me seriously look at possibly going 6870. In addition to being able to find parts easier, I'm currently looking to get a couple extra teeth climbing. Currently riding 53x39 with 10 speed 11-25; i am thinking about taking advantage of the 11 speed cassette 11-28.
Now - to pull this off, I believe I need:
chain (maybe, maybe not... i could use a new chain anyhow)
11 speed cassette
rear derailleur
front derailleur - thanks to firmware v3.0.5
I want to solidify that the Brifters are only switches. Thus the paired 6870 derailleurs will not care about being sent commands from 6770 shifters.
Also, with cranks being 53x39, can i use the short cage rear derailleur with 11-28 cassette?
Thank you!
Mike
In lieu of an accident Saturday, I am looking to replace my rear derailleur. Thus I have now found out firsthand how impossible it is to find new stock 6770 parts.This is making me seriously look at possibly going 6870. In addition to being able to find parts easier, I'm currently looking to get a couple extra teeth climbing. Currently riding 53x39 with 10 speed 11-25; i am thinking about taking advantage of the 11 speed cassette 11-28.
Now - to pull this off, I believe I need:
chain (maybe, maybe not... i could use a new chain anyhow)
11 speed cassette
rear derailleur
front derailleur - thanks to firmware v3.0.5
I want to solidify that the Brifters are only switches. Thus the paired 6870 derailleurs will not care about being sent commands from 6770 shifters.
Also, with cranks being 53x39, can i use the short cage rear derailleur with 11-28 cassette?
Thank you!
Mike
05-30-16, 01:51 PM
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as for short cage compatibility, i believe the formula to use:
top gear minus low gear for crank + top gear minus low gear cassette, should be lower then 32?
not sure if this is correct, but (53-39)+(11-28)=31
am i good to go there?
top gear minus low gear for crank + top gear minus low gear cassette, should be lower then 32?
not sure if this is correct, but (53-39)+(11-28)=31
am i good to go there?
05-30-16, 09:27 PM
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6770 brifters work fine with 6870 FD/RD. On mine, I just bought an 11-32 11 spd cassette, a GS 6870 and FD 6870 and bolted
them on. Left the 10 spd chain on as it was fairly new and everything works great. I was mostly interested in the 32t
available on the cassette with the GS RD. The SS RD should be fine with your 53/39 and 11/28
them on. Left the 10 spd chain on as it was fairly new and everything works great. I was mostly interested in the 32t
available on the cassette with the GS RD. The SS RD should be fine with your 53/39 and 11/28
05-30-16, 09:36 PM
#4
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as sch said, 6770 and 6870 are (almost) compatible... depending on firmware version. for the sake of others, the article is CarltonBale.com » Shimano Ultegra and Dura-Ace Di2 Electronic Shifting ? Everything You Need to Know
05-31-16, 06:47 AM
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6770 brifters work fine with 6870 FD/RD. On mine, I just bought an 11-32 11 spd cassette, a GS 6870 and FD 6870 and bolted
them on. Left the 10 spd chain on as it was fairly new and everything works great. I was mostly interested in the 32t
available on the cassette with the GS RD. The SS RD should be fine with your 53/39 and 11/28
them on. Left the 10 spd chain on as it was fairly new and everything works great. I was mostly interested in the 32t
available on the cassette with the GS RD. The SS RD should be fine with your 53/39 and 11/28
05-31-16, 06:50 AM
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so much here-say out on the internet its good to hear from some people who done it. not from their brothers, uncles LBS guru.
i hope my research was apparent, but still was looking for some peace of mind. Thank you again!
i hope my research was apparent, but still was looking for some peace of mind. Thank you again!
Last edited by unearth078; 05-31-16 at 04:39 PM.
06-02-16, 03:03 PM
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Got both derailleurs today. Confirmed 6770 shifters will work fine with 6870 mechs.
To be a bit smart, i plugged in the rear first and tried to shift - Nope! Plugged the front in, and they were both happy.
Cant wait to get my cassette and chain.
To be a bit smart, i plugged in the rear first and tried to shift - Nope! Plugged the front in, and they were both happy.
Cant wait to get my cassette and chain.
06-21-20, 01:57 PM
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Hi,
I tried to mix 6770fd with 6870rd, but it doesn't work and on my researches from google I found out that they won't work if the battery mount is updated to the latest version.
Now I found a battery mount with 2.1.1 firmware.Do you guys think it will work?Should I buy it?
Thank you.
I tried to mix 6770fd with 6870rd, but it doesn't work and on my researches from google I found out that they won't work if the battery mount is updated to the latest version.
Now I found a battery mount with 2.1.1 firmware.Do you guys think it will work?Should I buy it?
Thank you.
06-22-20, 06:51 AM
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You cannot mix 10 speed derailleurs with 11 speed derailleurs. Shimano blocked this in firmware at some point..
Now.. you could of course get a battery mount with older firmware (I'm not 100% sure that would work), but I would rather upgrade the front derailleur. An FD-6870 shouldn't be that expensive nowadays.. ;-)
(you also cannot mix MTB and road/grx derailleurs)
Now.. you could of course get a battery mount with older firmware (I'm not 100% sure that would work), but I would rather upgrade the front derailleur. An FD-6870 shouldn't be that expensive nowadays.. ;-)
(you also cannot mix MTB and road/grx derailleurs)
06-22-20, 07:02 AM
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You cannot mix 10 speed derailleurs with 11 speed derailleurs. Shimano blocked this in firmware at some point..
Now.. you could of course get a battery mount with older firmware (I'm not 100% sure that would work), but I would rather upgrade the front derailleur. An FD-6870 shouldn't be that expensive nowadays.. ;-)
(you also cannot mix MTB and road/grx derailleurs)
Now.. you could of course get a battery mount with older firmware (I'm not 100% sure that would work), but I would rather upgrade the front derailleur. An FD-6870 shouldn't be that expensive nowadays.. ;-)
(you also cannot mix MTB and road/grx derailleurs)
).Found out on other thread on google that they will work wit the 2.0.6 battery mounyt firmware version or older.
Now I found a battery mount with 2.1.1 firmware version and would like to know if it works.
06-22-20, 07:11 AM
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2.0.6 doesn't exist for the SM-BMR1 / SM-BMR2 according to Shimano 
However... if you _really_ want to get it to work.. there is a bit on carlton bale's page about downgrading firmware. Never tried that though..
Look for "INCLUDED FOR VERY MOTIVATED INDIVIDUALS ONLY" - https://carltonbale.com/shimano-di2-...-need-to-know/
- https://e-tubeproject.shimano.com/fi...&model=SM-BMR1
- https://e-tubeproject.shimano.com/fi...&model=SM-BMR2
However... if you _really_ want to get it to work.. there is a bit on carlton bale's page about downgrading firmware. Never tried that though..
Look for "INCLUDED FOR VERY MOTIVATED INDIVIDUALS ONLY" - https://carltonbale.com/shimano-di2-...-need-to-know/
