Session: AVT-06/02-01 Advances in Light Vehicles Design + Modeling and Test of Tires

Paper Number: 89204

89204 - Design of Customized Noncircular Chainrings for Cycling 

Noncircular chainrings have drawn the attention of the cycling community because they are designed to improve the pedaling cycle and obtain better performance. Nevertheless, there is no general agreement on their effect; for this reason, they are still under development, and further efforts to understand and improve this component are required.

In this work, a noncircular chainring with custom geometry was designed, manufactured, and tested. A numerical model was developed to study the effect of the chainring geometry on the mechanical advantage of the bicycle transmission system. A chainring with a custom geometry was designed to be manufactured. The manufactured chainring was installed on a road bicycle, and its mechanical advantage was measured through motion capture.

A custom noncircular chainring providing the target mechanical advantage profile was obtained. CNC machining was used for manufacturing the 1:1 scale functional prototype. The prototype was constructed in Aluminum 7075T6. The prototype was based on an elliptical geometry with 52 teeth. The ellipse used for the prototype had a minor axis of 97.60 mm and a major axis of 118.77 mm. The results of the experimental characterization of the chainring prototype showed a variation in the mechanical advantage obtained along a pedaling cycle within 0.194 and 0.233.

Presenting Author: Alejandra Polanco Pontificia Universidad Javeriana

Presenting Author Biography: Alejandra Polanco received the B.Eng. and M.Sc. degree in Mechanical Engineering from Universidad de los Andes, Bogota, Colombia in, 2010 and 2011, respectively. She received the Ph.D. degree in sports engineering from Javeriana University, Bogota, Colombia, in 2021. She is a lecturer at the Department of Industrial Engineering in Javeriana University, Colombia. Her research interests include bioengineering and sports engineering in topics as measurement and simulation of the dynamic response of systems and the analysis of human-machine interactions (email: alejandra.polanco@javeriana.edu.co)

Authors:

Alejandra Polanco Pontificia Universidad Javeriana
Jose Duran Universidad de los Andes
Luis Munoz Universidad de los Andes
Santiago Sabogal Universidad de los Andes