Originally Posted by
Kapusta
So in your case, I guess you need a slacker seat tube angle than most. Do you know around what seat tube angle becomes too steep for you?
Relating this back to the OP’s point, you don’t really need the measurement he is describing, you just need to know the STA is not to steep. Do I have that correct?
Doesn't matter for this discussion. We have no idea of the OP's requirements. When buying a bike, the thing to do is to sit on it on a trainer in the shop and have them adjust it and swap components to suit your preferences. If they can't, probably wrong size or sub-optimal frame angles for you.
I've found that there is a tendency of some manufacturers to use steeper STAs in smaller sizes to reduce toe overlap - at the expense of fit of course.