Would I need a new derailleur?

[BigonaBianchi]

Like this one?

http://www.rosebikes.co.uk/article/shimano-ultegra-rd-6800-gs-rear-derailleur/aid:675721

 

[Nigelnaturist]

Like this one?

http://www.rosebikes.co.uk/article/shimano-ultegra-rd-6800-gs-rear-derailleur/aid:675721

Or this even

http://www.chainreactioncycles.com/shimano-ultegra-6800-11-speed-rear-mech/rp-prod108734

 

[BigonaBianchi]

blimey...confusing ain't it...ha ha!

ok....so if if I hit 'Go' of this lot would it all be compatible?


Derailer
https://www.rosebikes.co.uk/product/detail/aid:675721

11-32
https://www.rosebikes.co.uk/product/detail/aid:443896

12-30
https://www.rosebikes.co.uk/product/detail/aid:573978

Chain
https://www.rosebikes.co.uk/product/detail/aid:98426


I'm thinking I will get both cassette options and switch them as needed.

 

[Nigelnaturist]

I would get them from chainreactions, likely to be quicker and cheaper.

 

[ayceejay]

If I were you I would stick with Ultegrs. Go to Chain reaction as suggested and get the cassete/ chain combo and the appropriate RD.
I have a feeling that your suggestion (a mix of road and MTB parts) will lead to trouble.