You'll be fine on the 56. I'm 4cm shorter than you. If you look at the Scott dims I posted above and compare the 54/m Addict to the 56/m SL, you'll see they're almost identical. the only significant difference being the head tube on the Addict is 140mm as apposed to 150mm of the SL. Other than that they only differ by a few mm here and there, and the SL is generally smaller