Most competitive and recreational road cyclists use rigid-soled shoes designed for cycling and “clipless” pedals that firmly attach to the shoes. There are many unsubstantiated claims by cyclists and industry professionals about the advantages of cycling shoes and clipless pedals. Scientific research has shown that cycling shoes and clipless pedals have no significant effects on the metabolic cost of cycling during submaximal, steady-state efforts. However, Burns and Kram (2019, pre-print) demonstrated cycling shoes and clipless pedals do provide performance benefits relevant to sprint cycling. Here, I investigated if there was a positive relationship between longitudinal bending stiffness in cycling shoe soles and sprint performance. In this study, I measured the mechanical power outputs, velocities, and cadences of 19 healthy male recreational/competitive cyclists (age: 30.2 ± 7.7 years, body mass: 73.8 ± 7.2 kg, height: 179.0 ± 3.4 cm, average cycling per week: 9.2 ± 3.2 hours, road cycling experience: 10.5 ± 6.9 years) during maximal sprint cycling with the null hypotheses of no differences in performance. Participants rode outdoors on a paved asphalt road with a steady, uphill grade of 4.9%. Each subject completed nine 50 meter cycling sprints in three (single-blinded) shoe sole conditions with identical shoe uppers: injection molded nylon soles, carbon fiber composite soles, and full carbon fiber soles. The same clipless pedals were used throughout all tests. No significant differences were detected between the three shoe soles for: 50 meter average and peak 1 second power, average change and peak change in velocity, average and peak cadence, maximal sprint velocity, peak acceleration, and peak crank torque (p > 0.05). Increased longitudinal bending stiffness of cycling shoe soles had no effect on sprint performance during short uphill sprints.
_ In a follow-up study, I developed a mobile strain/strain distribution data acquisition system for use with cycling shoes. An Arduino Microcontroller and microSD card were used for data logging. A Sparkfun HX711 was used as an analog to digital converter and a load cell amplifier. I used a proof of concept test with a strain-gauged cantilevered aluminum beam to determine the device’s response to a known strain. I then used the data from the proof of concept test to perform a stationary cycling pilot study with three sets of strain gauges mounted to the sole of a cycling shoe. The device shows promise for outdoor data collection during sprinting.