Originally Posted by
jackbombay
this is with a park tools bike stand that has a fairly large grip that distributes pressure over a larger area of the frame than other bike stands I have seen.
The Park 100-3C/5C clamp can distribute some serious pressure, but it's also designed to deliver that pressure evenly with its curved surfaces, even if the rubber jaws are worn out. Enough so that I feel confident hanging 531 frames from them, occasionally by the seattube (sorry @
Charles Wahl ), with the addition of a rag. The clamp lock is also designed in such a way that you do not have that much mechanical advantage when closing the lever - in part to prevent crimping of tubing, like this.
I
do think a clamp was responsible for this, but of a different design - one capable of producing enough torque to flatten the tubes easily and V-shaped groove that'd explain the pronounced dents at each end.
The Park 100-7X seems like a possible candidate, and the micro-adjust version - which seems popular for shops to use with CF bikes now - also has a crank design that is more likely to provide way too much mechanical advantage for the repair person with oatmeal for brains. It also fails on having a truly curved main clamping surface.
-Kurt