Torque indicating device

The torque indicator (23) comprises outer and inner parts (22,24) connected by radially extending torque transmitter (28) provided with a torque sensor (30) to produce a signal dependant on the transmitted torque. A communication device includes a radio transmitter receiving the signal produced by the torque sensor, and communicating an output signal dependant on the torque through an aerial (33) to a receiver. An amplifier may provide and output signal which may be fed to a single to bipolar converter so as to give a signal dependent upon the direction of the torque being transmitted. The output of the converter may be fed to a microprocessor. Electrical supply is provided by a battery (B). The torque sensor comprises strain gauges connected in a bridge formation. The device may also include a speed sensor so that power can be calculated.