Hi,my name is xristos and i am 1.75cm height…
I want to buy a storck Fascenario 0.6 or 0.7 frame…
Which size will be the most fit for me???
Size 51 or 55???
I will appreciate all the replies… 
thank you for your time… 
This is not a lot of information to base a fit on. I am a Storck Dealer and would be happy to help you, but you need to provide more meaningful data.
Inseam and Torso length at bare minimum. you can also contact Storck directly and give them your dimensions and they will guide you into the correct size. If you have a road bike now the Storck sizing should be relatively similar.