Experimental examination of bicycle chain forces

This paper presents the results of an investigation evaluating the forces present in a statically loaded bicycle chain prior to and beyond sprocket engagement. Comparisons are made with previous investigations that have been limited to industrial chains and sprockets. The chain drive system for a bicycle differs from the industrial standard types not only in its size but in its operation. A high degree of lateral flexibility is required in the bicycle chain for it to operate with noncoplanar sprockets having an effective misalignment of 3 deg or more. The experimental analysis in this paper considers chain loads for a range of sprocket sizes and angles of misalignment. Results indicate that localized bending arising from misalignment between chain and sprocket can increase or decrease the strain on the side plates by a substantial fraction of the direct strain due to chain tension. The work presented here is part of a more general study of bicycle chain efficiency for competition applications.