Structure activity relationships in the mechanochemistry of gem-dichlorocyclopropane (gDCC)-based 2 polymer solutions triggered by pulsed ultrasound are reported. Insights into the flow-induced mechanochemical transformations of gDCC mechanophores into the corresponding 2,3-6-dichloroalkenes are obtained by monitoring the mechanochemistry as a function of initial polymer molecular weight and sonication conditions. The competition between gDCC activation and polymer chain scission is invariant to sonication power, temperature, polymer concentration, and solvent but is sensitive to initial polymer molecular weight. The results have practical implications for the use of polymer sonochemistry as a tool for quantifying the relative mechanical strength of scissile polymers and conceptual implications for thinking about the nature of the force distributions experienced during sonochemical experiments.