The short answer: Probably not.
The long answer: Most articles on elliptical chainrings will tell you they’re nothing new. That they date back to the 1890s. That Shimano manufactured an elliptical chainring in the 1980s called the Biopace and, aside from a few love letters, the component was generally panned for causing undue stress on the knees.
The idea behind the ellipse, as BikeRadar explains, is to eliminate the “dead spot” when your feet are at 12 and 6 and can’t produce much power. The non-round shape should allow you to apply more power through the entire pedal stroke.
Should being the operative word. Researchers have examined the physiological and performance differences between elliptical and round cranks time and again. And time and again, they’ve concluded that, when it comes to power output, heart rate, perceived exertion, and blood lactate during efforts longer than one kilometer, there’s not much difference between round and elliptical chainrings.
However, some researchers cautiously suggest that, while the eccentric design does not affect performance, lactate, and heart rate, it could improve 1K times of people with really muscular legs. Like track cycling stars.
Rather than proven science, the current elliptical revival is built on smart marketing and high-profile endorsements. Bradley Wiggins rode the Osymetric brand chain ring during his winning 2012 Tour de France Campaign and Olympic time trial, only to ditch them recently, telling the BBC, “I’ve come off those silly things now.” Head of operations of Wiggins’ Team Sky told BikeRadar later, “[There isn’t] any evidence that this gives you this [advantage], so it’s up to the rider’s feel.”
And that’s exactly where we’re at now. It’s all about how you feel. Modern elliptical chain rings make some bold and unverifiable claims about the product’s advantages (Osymetric, whose chainring is not an ellipse, but asymmetrical, says their design will give you “7-10% more wattage without doing any more work,” and a “12% reduction in lactic acid buildup”).
But ultimately, it’s about personal preference. If the Osymetric or Rotor Q-Rings feel more natural to you than a circular chainring, use them. Just don’t expect any amazing insta-transformations from thinking outside the circle.