To use a bike instead of round sprocket Ellipso suggested in 1892 Professor V. Prusakov. He decided to put the rods along the minor axis of the ellipse that has allowed more efficient use of the power of the cyclist. Experiments have shown that even an inexperienced rider on a machine with the elliptical sprocket expends energy approximately 30% lower than on moving with the same speed filemashine with a round sprocket. And according to the American engineers, the use of oval zubchatki increases the average speed of a cyclist by about 14%.
But, despite all this, the non-circular sprocket is not widespread nor we, nor abroad: velopment were not ready for the production of non-traditional components of the chain drive.