Originally Posted by
Kapusta
Here is me trying to explain that modern oval rings (e.g., Absolute Black) are not the same thing as Biopace...
Me "New oval rings are not the same thing as Biopace"
Them: "But, they are both oval"
Me: "The clocking is different... the increase and decrease in gearing happens at different points in the pedal stroke and therefore work very differently"
Them: "But they are all oval. Same thing, just different marketing"
Me: "Biopace was not actually oval"
Them: "Close enough, same thing"
Me: "Have you ever ridden a new oval ring like Absolute black?"
Them: "I rode Biopace 25 years ago, and did not like them so I know I don't like oval rings"
Me: "But these don't work the same way"
Them: "They are all oval. Companies keep trying oval rings and they keep failing"
Me: "They are not failing, oval rings have been well received in the MTB world for a few years now. And that is because they do not work like Biopace rings"
Them: "But they are all oval, same thing as Biopace"
And so on, and so on.....
Yup. Some folks nitpick terminology either to refute or defend their pet position on chainrings. That's why I call them all eccentric. That's an adequate one word summary, including for ovals, egg-shaped objects and the peculiarly rounded near-parallelogram shape of some smaller Biopace rings.
I suspect more people who dislike them didn't spend enough time on overall bike fit to make 'em work -- for example, trying various crank lengths as I did. But I'm not sure it's worth the hassle for most folks either. Any gains are pretty small. I only spent a lot of time on Biopace out of curiosity. And it wasn't my only road bike so I had time to fiddle around with three different crank lengths, adjusting saddle height and overall position, handlebar/stem height and reach, etc.
If I had tried Biopace with only my 175 cranks and didn't make any other changes, I probably would have dismissed them after the first sign of a knee twinge.
But after finding a setup I liked my data shows I was consistently a bit stronger on climbs and a bit faster on my usual roller coaster workout routes. And my stats have shown a slight but consistent decline this year since switching back to regular round rings.
However that decline could also be attributed to aging and bouts with a minor but persistent upper respiratory inflammation all year. Too many variables to say whether switching away from eccentric chainrings was a significant factor.
So I'm going to put the Biopace rings back on one bike and try again.