Abstract <p>We support a preliminary determination of the catch-bond character of a mechanical–chemical toy model using a tweezers construction with some modifications. We discuss a theoretical analysis of the problem using Newton trajectories. We propose a two-dimensional potential energy surfaces for this model. We discuss the slip, ideal and catch-bonds for this model using the previous potential parts of Dansuk and Keten (Matter 1:911, 2019). Chemical examples of the ansatz are allosteric reactions, especially FimH proteins. We note again that Newton trajectories provide the theoretical background of mechanochemistry. Construction of a potential energy surface and use of Newton trajectories by Wolfram Mathematica. Calculation of real catch bond behavior. We get for a tweezers model the catch bond behavior.</p> Graphical abstract <p> Two barriers under external force, F. The catch-bond barrier increases.</p>