Brake reaction bars that do not that have chassis fittings that shear is unwise in a dangerous impact. The brake reaction bar goal is to steady the front end when braking, not to become a
structural feature that transfers impact forces to occupants.
Struggling with this theory on how a small tube structurally pinned at each end can transfer impact forces to occupants.
When subject to a frontal impact of any significance the tube will buckle under compressive loading if the lower location bolt doesn’t shear. This will effectively render its contribution to the stiffness of the car to zero.
Occupants in an impact experience a rapid deceleration, the extent of which influences the energy released. The stiffer the car the more rapid the deceleration the more energy is expended. Crumple zones are designed to reduce deceleration which reduces energy. The stiffness of a small brake reaction bar will be several orders of magnitude less than that of the chassis and consequently will have minimal influence on energy transferred to occupants in a frontal collision.
