First time Bike CAD user, so be gentle...
I've loaded a design in from the archive. On entering the "primary dimensions" dialogue, changing the head angle and seat angle change the on screen geometry.
Changing the seat tube length or top tube length don't update the view.
Is there something I'm doing wrong?
You must hit the "Enter" key after typing in a new value.
Let me know if that does not solve the issue.
Thanks for giving BikeCAD a try!