Frame Size, Center of Gravity, and Bike Handling

[RoadRaven]

Hi there... frame size can be n the smallish side, but how you position yourself on the bike will have a big impact.

Below is my TT bike - it is a medium frame size, I am 5'10' (My road race bike is a large)

The seat post is out to its absolute safe max but because I am low on the bike when on the aeros, my centre of gravity is more "central"

If I rode this bike in a more upright position - like my mother's bike which has the bars high (mum cannot lean forward and put weight on her shoulders... her back is near vertical to the ground) then my centre of gravity would be unbalanced on the bike and it would, I imagine feel quite squirrelly.