What's the correct position to assemble eliptic (Biopace, Rotor, etc) chainrings? If you take a regular, "classic" road chainring (130bcd, five arms), you have five possible positions to assemple it in the crank arm. This can even be used to "rotate" between different positions over the chainring lifetime and get a more homogeneous teeth wear.

But with elliptical chainrings, there should be only ONE position, shouldn't it? I mean, it was designed to have the larger chainring radius in a given position, so the question is: which position was it designed to work best?

Aditional question: would it be possible/wise to "tune" the performance for a given riding style, possibly going "against" what the manufacturer designed? It looks like RotoR and Biopace have different theories about that...
IIRC, there are at least 3 conflicting theories:


The rings should be oriented to extract the maximum energy from the most powerful part of the stroke (from roughly 3-oclock to 6-oclock, viewed from the right).
The rings should be oriented to maintain a (relatively) constant forward force/velocity, despite the change in leg force through the rotation.
The rings should be oriented to maintain "smooth" leg motion.  (Whatever that means.)


(1) would have the largest diameter parallel to the cranks, (2) at right angles, (3) somewhere else.

Update:  I have 1 and 2 backwards -- see jae's answer on that point.