Quantifying power output during cycling through measuring strain energy in a bicycle frame

Quantifying power output is becoming more popular in training and competition for cycling. This popularity comes from the fact that power is a direct means of measuring intensity, which is considered by many to be the most important variable in a successful training program. Although other methods are available for measuring power output, there is no frame that is available that uses strain to quantify power output. Using a frame may prove superior to currently available products. Additionally, strain may prove useful for cycling technique analysis, another critical factor for success. In this study, a cyclocross bicycle frame was instrumented with six strain gages to determine if strain energy in the frame correlates with power output. For pilot data, an 85 kg subject rode the bike on rollers with a fork stand at 250 watts and a cadence of 90 rpm. Although more data needs to be collected and analyzed to find a correlation with power output, initial pilot data shows that the strain in the frame is cyclic in nature when pedaling and has a corresponding frequency with the pedaling cadence. It is hypothesized that the strain in the frame will have a high correlation with power output. While this application is specific to cycling, correlating strain to power output may prove useful in other applications.