If you are defining the front end geometry by stack and reach, you'll want to leave that menu selected to lock in those values. This is discussed at: bikecad.ca/toptube_frontcenter. You can then adjust the angle of the top tube by changing the seat tube length. Another thing that ties into this is tube extensions described at: bikecad.ca/tube_extension.
If you are defining the front end geometry by stack and reach, you'll want to leave that menu selected to lock in those values. This is discussed at: bikecad.ca/toptube_frontcenter. You can then adjust the angle of the top tube by changing the seat tube length. Another thing that ties into this is tube extensions described at: bikecad.ca/tube_extension.