Soft robots have shown their value as alternatives or supplements to rigid robots in applications like search and rescue missions and complex precise tasks. Their ability to take on various shapes and apply adaptable force gives them an advantage over stiff robots. However, sometimes their soft structure doesnot offer enough force for the task. Hybrid soft robots (HSRs) combine a soft body with a stronger backbone to handle tasks needing more strength. This rigid part lets us use rigid body dynamics to estimate HSR behavior. Here, we introduce a simplified N-link rigid body dynamic model with constant stiffness to mimic HSR behavior. While soft robots stiffness varies, the backbone in HSRs makes it similar to having constant stiffness. Comparing experiments supports the effectiveness of our N-link model for HSR modeling.