of mechanochemical reactions, especially for those initiated by tensile force. It is known that stereochemistry plays an important role for determining the activation force F act (i.e., cis-isomers are more reactive than trans-isomers), however, the presence of a highly-strained cyclopropane ring was thought to contribute the most to the reactivity. Recently, the Boydston group has confirmed the mechanochemical reactivity of VA-PNB (vinyl-addition polynorbornene) under sonication conditions and owed its reactivity to the strained rings. However, as shown below, the reactivity is actually caused by a specific confirmation (named "node" by us) rather than the ring strain. We first raised this idea back to 2022 when we studied the retro-Diels Alder reaction using the extended artificial force induced reaction method (EX-AFIR method). We have also noticed that Moore and co-workers have extended this concept in their recent work. Given this, we studied the reactivity of both cis-VA -PNB and trans-VA -PNB under a variety of force levels using EX-AFIR method, and the results are shown in Figure Figure . ΔG ‡ τ -F τ graph of cis-VA -PNB and trans-VA -PNB, suggesting ring strain is not the major reason for the mechanochemical reactivity observed in the sonication reaction.