This is an enjoyable read since we are looking at this decades later. It sure seems that Shimano put great effort into the design. I haven't tried Biopace, however, I had a bike only briefly that had a SunTour version of BioPace. I didn't get enough time on it to get a feel if it would be better for me. I also have chondromalisia, so I would, at some point like to try it out.

"Chris Froome uses oval chainrings so it's not like this idea has completely gone out of style." Is this perhaps why people have commented that he pedals like a washing machine? bikemig

I think athletes work to accommodate the equipment they use. Maybe BioPace is the domain of amateurs and tourists.