A first pedaling force measurement device measures a plurality of pedaling force parameters acting on a first crank arm to one end of which a first pedal can be attached and to another end of which a crank shaft can be attached. The first pedaling force measurement device is provided with a strain-flexing part, a first parameter detection part and a first interference suppression part. Strain acting on the first crank arm is conveyed to the strain-flexing part. The parameter detection part is disposed on the strain-flexing part, and detects a plurality of parameters based on the strain being conveyed to the strain-flexing part. The interference suppression part suppresses interference in one parameter detected by the parameter detection part from the other parameters.