Originally Posted by DannoXYZ
Yup, there's where a stress-riser occurs. This is cause by high-torque due to the long moment-arm with the force starting at the handlebar ends and the pivot at the stem. The stress is concentrated on the edge of the stem where the bar first goes in. This is the transition point for flex vx. zero-flex of the material. It's like hammering a nail halfway into a 2x4. Then bending the exposed half with pliers until it breaks. It will usually break within a millimeter or two from the point where it sticks into the wood.
The physics of this all make sense. The reason I'm asking is because the Modolo 8-bend bars seem to be flexing at one of the upper bends, not at the stem. Though I'll have to test this again and have one of my housemates watch.
Are you in physics or engineering stuff? My last class in either of those disciplines was spring 1999, though I've kept fresh by testing prototype running shoes.