Use the Lock frame icon to see how a specific frame would look with a different fork or wheel. If the Lock frame icon is not selected, the frame will change shape to retain the initially specified seat angle and head angle.

Note: The lock frame option does not work when you switch the fork menu from Custom fork to Standard fork. It will work for both custom forks and standard forks. The problem is when you switch the menu from custom to standard. Look for this to be corrected in the next version of BikeCAD.