Originally Posted by
corrado33
The rings were installed so that on the power part of the stroke, you had an easier gear (smaller part of the oval on top) and on the dead part of the stroke, you had a harder gear. So basically the larger part of the ring was lined up with the cranks.
That's exactly how BioPace rings were supposed to be installed, if I'm reading your description correctly.
Most elliptical chainrings put the bigger effective gear during the power strokes, but Shimano's research told them that the bigger gear worked better during the dead spot of the rotation.