Are there any scientific studies proving the benefits of clipless pedal systems?
The Pedaling Technique of Elite Endurance Cyclists: Changes With Increasing Workload at Constant Cadence was published in the International Journal of Sport Biometrics 7:29-53, 1991. However, it seems to come to the conclusion that they don't really make any difference as far as pedaling efficiency goes.
&quot;...while torque during the upstroke did reduce the total positive work required during the downstroke, it did not contribute significantly to the external work done because 98.6% and 96.3% of the total work done at the low and high workloads, respectively, was done during the downstroke.&quot;
This is echoed in Physiological and biochemical determinants of elite
endurance cycling performance published in the Medicine and Science in Sports and Exercise 23:93-107, 1991. There are numerous graphs showing that pedal force is only exerted between the top and bottom of the downstroke, represented by a very sharp parabola spiking at 90 degrees from vertical.
That said, I think it's obvious to anyone who has ever done any particularly technical riding with and without clipless pedals that clipless pedals significantly improve the handling of a bicycle. A fact which is probably more difficult to verify through scientific studies.