Originally Posted by
Carbonfiberboy
Huh. That's a pretty solid statement, isn't it? No effect, eh? So have a look at these geometry charts, and tell us why manufacturers changed the STA unless it was for toe overlap. We notice that both STA and HTA change with frame size.
https://forums.roadbikereview.com/gr...ve-353212.html
Some manufacturers hold STA steady with frame size change, but by no means all.
Please explain how seat angle could influence or mitigate toe overlap. Toe overlap is a function of the distance from the bb to the front axle. This is mainly determined by reach, head angle, and fork offset, wheel/tire diameter, and to a lesser extent by stack and fork length. I can't see how STA would have any effect on this distance.
You do often see differences in head angle and fork offset on smaller frames, and I always assumed that was to help address issues of toe overlap.
I don't really know why they change the STA, but my best guess would be because they anticipate a difference in the bb to saddle fit needs for shorter legged riders.