A system for sensing the load carried in a structural member by attaching a load cell to a neutral axis of bending. Small deflections along an arc of bending create a desirable signal level via mechanical amplification. A load sensor is adapted for mounting on an axle that deviates from a neutral axis when under a load. The load sensor comprises a reaction portion adapted for mounting on the axle and an active portion adapted for mounting to at least two points along the axle. The active portion has an amplifier arm and at least one sensor element. The sensor element is attached at a first end to the reaction portion and the sensor is attached at its second end to the amplifier arm. At least one strain gauge is mounted on the sensor element. At least one flexion web is attached to the reaction portion and to the active portion. When a load is put on the axle, flexion of the axle moves the active portion relative to the neutral axis of the axle, the active portion moves the amplifier arm, causing a curve to be formed in the sensor element, the curve being of sufficient magnitude to be calibrated by the at least one strain gauge.