A rear hub assembly for a bicycle, comprising: an outer freehub member having a drive gear arrangement mounted thereon so as to be rotationally fast with the outer freehub member, wherein the outer freehub member defines an interior, and wherein the drive gear arrangement is adapted to be driven by power applied by a user to pedals of the bicycle; an inner freehub member contained within the interior of the outer freehub member such that the outer freehub member is disposed on and rotationally supported around the inner freehub member, the inner freehub member being rotationally fast with a hub body to which, in use, the rear hub assembly is connected; and a one-way clutch interposed between the outer freehub member and the inner freehub member for transmitting rotation of the outer freehub member to the inner freehub member in only one direction so as, in use, to propel a wheel of the bicycle; characterised in that the outer freehub member includes a torque sensing arrangement provided on the outer freehub member, which is configured and arranged to sense torque transmitted through the outer freehub member to the inner freehub member of the rear hub assembly through the one-way clutch by detecting torsional strain in said outer freehub member, the assembly further comprising an electronics assembly interconnected with the torque sensing arrangement, wherein the electronics assembly receives signals from the torque sensing arrangement corresponding to torque experienced by the outer freehub member upon application of power by a user to the drive gear arrangement, in use, processing the signals to create torque data, and transmitting the processed torque data to a receiver. an outer freehub member having a drive gear arrangement mounted thereon so as to be rotationally fast with the outer freehub member, wherein the outer freehub member defines an interior, and wherein the drive gear arrangement is adapted to be driven by power applied by a user to pedals of the bicycle; an inner freehub member contained within the interior of the outer freehub member such that the outer freehub member is disposed on and rotationally supported around the inner freehub member, the inner freehub member being rotationally fast with a hub body to which, in use, the rear hub assembly is connected; and a one-way clutch interposed between the outer freehub member and the inner freehub member for transmitting rotation of the outer freehub member to the inner freehub member in only one direction so as, in use, to propel a wheel of the bicycle; characterised in that the outer freehub member includes a torque sensing arrangement provided on the outer freehub member, which is configured and arranged to sense torque transmitted through the outer freehub member to the inner freehub member of the rear hub assembly through the one-way clutch by detecting torsional strain in said outer freehub member, the assembly further comprising an electronics assembly interconnected with the torque sensing arrangement, wherein the electronics assembly receives signals from the torque sensing arrangement corresponding to torque experienced by the outer freehub member upon application of power by a user to the drive gear arrangement, in use, processing the signals to create torque data, and transmitting the processed torque data to a receiver.