Peter, You say it: it 's not a matter of increased work (of course not) but a matter of improved crank power efficiency. A circular chainring seems to be not the most efficient solution.
http://www.noncircularchainring.be In case you want to learn more about non circular chainrings, please read above mentioned scientific study. I am looking forward to receive your comments. Bike Tech2007-08-19 07:19:22
