Ok so this may be a dumb question, but what is the difference between Frame Stack Height and Geometry Stack Height? Same for Reach as well. I ask because Rattlecad is giving me two different numbers for each depending on if I'm in the Geometry tab or the Frame & Frame Tubes tab.

I'm trying to understand how you can get two different numbers if they're measured to the same place. Unless they aren't. If they aren't, then why? I don't know which one to use to help in my design. The Stack numbers are 18mm different and the Reach is 6mm off. I don't get it. Help me understand.

Thanks in advance.

Brandon