A hand grip 1 for an electric bicycle comprising a first sensor 4 to monitor the physical state of the rider, a second sensor 8 to monitor atmospheric pressure, and a control unit 9, 10 to transmit a demand for battery powered assistance to pedal action when required in response to the output of both the first and second sensors. The first sensor is preferably a heart rate monitor, and the second sensor is preferably a barometric pressure sensor. The bicycle preferably has manually operated gears and a battery powered motor. Preferably the sensors and controller are all housed within a handlebar grip, or in another embodiment the control unit may be mounted to the bicycle frame independently of the hand grip. The handlebar grip preferably includes a user interface with sensor mode selection and visual feedback of pulse, has training levels and climb detection, and is preferably mounted within a waterproof housing.
