Finally spent some time tonight mucking around with my bike, my rings, my cleats etc.
I have been riding with the speedplay cleat adaptor for about two weeks in the most rear-set position (allowing a setback 25mm behind where I was before under the ball of the foot).
I have also been toying with the Rotor rings as well.
Here are two plots from tonight (average of 30s pedaling on an erg):
and
I will let you draw your own conclusions for now…
more to follow
-g