Originally Posted by Carbonfiberboy

Ah. That's a little more complicated. If you are of average proportions, a frame size of 49-50 cm should be about right. If you're not, go to this website: https://www.competitivecyclist.com/S...ulatorBike.jsp
and with an assistant, take the required measurement and put them in. The calculator will produce some figures for different styles of fit. Look at them all. The two most important frame measurements are effective seat tube length and top tube length. So then you need those measurement for the bike in which you are interested. If they're close, you're golden, close meaning within a couple centimeters.

The bike you're considering is a rather old frame style and the bars are a bit weird. It's really something you want to sit on and then take for a ride.