Abstract: A rake head comprising at least one substantially rigid helical coil portion and at least one resiliently deformable helical coil portion. The substantially rigid helical coil portion is supported. The deformable helical coil portion is able to flex by bending, and is compressible under the influence of external forces.

Abstract: An apparatus for determining the imbalance in a rotating object has a drive means for rotating the object about an axis. Transducers measure the force of imbalance of the rotating object, with each transducer producing an electrical signal in response thereto. Electronic means receives the signals from the transducers and calculates the imbalance in the object. Drive means is directly coupled to the rotating object, such as a tire, with the drive means in the hub of the wheel on which the tire is mounted. Cantilever support means having a substantially planar surface provides support for the drive means onto the transducers in the frame of the apparatus.