In this body and its members should not be distorted. That these conditions must meet its mechanical properties. The rigidity of protection can be considered optimal if the deformation occurs only within the gap between it and the sump (usually a gap of no more than 20-30 mm, so as not to greatly reduce ground clearance). This is due to the fact that: too much rigidity of protection can result in damage to body, as all the impact energy will be transferred to him; crankcase with insufficient hardness can sometimes translate into a frontal attack rolling, but can stretch into the crankcase and cause damage. In addition, the stiffness determined by the condition safety – in a frontal collision the engine has to move down instead of towards the driver and front passenger.
To protect this did not prevent it from bending down is made. It provides its aimed at crushing the deformation front of the car. The strength of protection provided by design and materials used. It must be such as to withstand without serious injury hit a sharp stone, metal rod, etc. The strength of attachment is achieved by using appropriate fasteners and installation of security only for the power components of the car – spars body sub-frame motor transverse beam suspension. Considered to be insufficient to mount a weaker protection elements, such as cross member under the radiator, which is only valid for the anthers. In the case of such a facility can protect the radiator suffer from a stroke.