Bicycle Power meter with frame mounted sensor

摘要

A bicycle power meter has a strain gauge sensor (30) assembly mounted on a relatively compressible portion of the end-of the rear fork (12) of the bicycle frame. The relatively compressible portion is near the rear hub (20) and subject to the forces exerted by the cyclist to the crankset, and transferred via the chain (24), and sprocket assembly to the hub (20). The sensor assembly has two ohmically interconnected stretch sensors each having a first layer bearing a variable resistance element, whose resistance changes with displacement of the compressible portion, and-a second layer for providing support for the first layer. The sensor assembly (30) is connected in a bridge circuit to two other resistances to generate signals representative of cyclist applied force. These signals are processed along- with velocity signals to generate power signals and the power signals are supplied to a display.