Normally 10 cm inserted or more is fine.
What size frame is it, and what's the head tube length?
It looks like a 54 or 56 cm frame, with a 16 cm head tube. If so, you have about the same seat height as me. It's not uncomfortable if, er, you don't find it uncomfortable.
I guess the posters here are just trying to be helpful to be fair.[/QUOTE
The frame size is 52.5. The geometry seems to be a bit different to most road bike, Truthfully, I don't understand, but at very close to 5ft 11 this is the correct size. its also set the same as my old bike which happened to be a 58, the seat is at the same height as are the handle bars, However I have to agree, it does look small.