Did a quick and dirty check to see how flexy my frame is. Just stuck a laser pointer on the rear fender with a magnet and aimed it at a notecard taped to the front fender. Marked the position of the dot, then jacked the wheels off the ground and marked the position of the dot again.
Have nothing to compare it to, but will check this in the future after some restoration work. If anyone is game to try this, it would be interesting to compare.Click to view attachment
Click to view attachment
Click to view attachment