By Steve, Aug 1 2019 06:19PM
Researchers and bicycle component designers have sought to increase maximal cycling power by manipulating aspects of the pedalling motion, which include crank length, novel crank-pedal mechanisms, and chainring shape. Non-circular chain rings were initially described as early as 1896 and have occasionally become popular in competitive cycling
In this study:-
Part I: Thirteen cyclists performed Maximal inertial-load cycling under 3 chaining conditions.maximumcycling power and optimal pedalling rate were determined.
Part II: Ten cyclists performed maximal isokinetic cycling (120 rpm) under the same 3 chaining conditions. Pedal and joint specific powers were determined using pedal forces and limb kinematics.
Neither maximal cycling power nor optimal pedalling rate differed across chain ring conditions (all p > .05)
This paper suggests that cyclists adjusted their ankling action to maintain their preferred knee and hip joint angular velocity profiles to preserve power production.
In summary, noncircular chain rings did not enhance or compromise maximal cycling performance in these trained cyclists, as maximum power and optimal pedalling rate remained unchanged.
To these researchers knowledge, this is the first investigation to compare power pedalling rate relationships, and joint-specific kinematics and kinetics during maximal cycling with circular and noncircular chain rings. Their results provide insight into the extent to which noncircular chain rings alter cycling coordination and power production.
Full paper can be found at:-
Leong, C.H., Elmer, S.J. and Martin, J.C., 2017. Noncircular Chainrings Do Not Influence Maximum Cycling Power. Journal of applied biomechanics, 33(6), pp.410-418. (Information extracted from this paper)