A sensor assembly for determining an amount of wear on a brake pad in a disc brake includes a shaft extender having a first end coupled to one end of a shaft of an adjustment mechanism of a caliper of the disc brake for rotation with the shaft about a rotational axis and a second end defining a shaft extension. A sensor generates a signal indicative of a degree of rotation of the shaft extension with the signal indicative of the amount of wear on the brake pad. The sensor includes a body coupled to the shaft extension and configured for rotation about an offset axis offset from the rotational axis in response to rotation of the shaft extension about the rotational axis and a measurement device configured to generate the signal responsive to rotation of the body about the offset axis. A housing encloses the sensor.