# Can I Add 6870 r derailleur to 6770 Bike



## jackmen (Jul 24, 2007)

I have a full 6770 Ultegra set up on my road bike that is 1.5 years old. I would like to upgrade to 11 speed, but understand that I need a new Rear derailleur to do so.

Can I just add a new 6870 rear derailleur and a new 11 speed socket to my existing 6770 bike and just reprogram? Will this work? I do realize I need a different rear wheel to use the 11 speed sprocket.

I do have the PC interface for my unit. 

Need some help.


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## Madone SIX (May 13, 2012)

jackmen said:


> I have a full 6770 Ultegra set up on my road bike that is 1.5 years old. I would like to upgrade to 11 speed, but understand that I need a new Rear derailleur to do so.
> 
> Can I just add a new 6870 rear derailleur and a new 11 speed socket to my existing 6770 bike and just reprogram? Will this work? I do realize I need a different rear wheel to use the 11 speed sprocket.
> 
> ...


Yes. You just need either an RD-6870 or RD-9070 and an 11 speed cassette/chain. Then just update the firmware and you are good to go.


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## chojn1 (Sep 13, 2012)

Madone SIX said:


> Yes. You just need either an RD-6870 or RD-9070 and an 11 speed cassette/chain. Then just update the firmware and you are good to go.


Just want to update this post to reduce any chance of confusion.
Mismatch system between 10 sp front derailleur (6770) and 11 sp rear (6780, 9000) is no longer allowed by Shimano as of July 2014.

You can still get it to work if you have an old battery mount (without the current firmware). If Shimano finds out (i.e. during software upgrades), they will shut down both derailleurs.


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## willieboy (Nov 27, 2010)

Just did this conversion yesterday. Due to the current firmware I had to change both front and rear derailleurs. Works perfectly with the 6770 levers.


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