Oval Rings, Demystified

 OVAL RINGS, laymans' terms edition.
*if you want to go full-send into the science, click here! 

Everyone knows that ROTOR Components are famous for our oval "Qring" chainrings. But what's hot take on this key product? 

 

THE BIG ONE: Reduced time in the dead spot of your pedal stroke. 

People always think about being able to push harder where they're strong, but an oval chainring is really all about minimizing the resistance at the back of the pedal stroke, where it's weakest.  

ROTOR has a patent on the ability to "clock" or adjust the position of the oval in accordance with the rider's point of maximum power. For us, this means the difference between an effective help or something that is either ineffective or actually detrimental to the pedal stroke. 

For instance, a triathlete's point of maximum power (OCP - Optimal Chainring Position, in ROTOR parlance,) will be quite different from a XC mountain bike racer's sweet spot, if you will. Having a correctly positioned oval reduces drag on the back part of the pedal stroke, reducing the time spent in the so-called dead spot. 

Want to see it quantified? (Trick question, who doesn't??) Check out this screengrab from our INpower app, which shows a graphic pedal stroke analysis. The L & R sides of the peanut correspond to the L & R legs, the green line on the right shows the point of maximum power in the pedal stroke (also referenced numerically as the "OCP" or Optimum Chainring Position. (OCA is Optimum Chainring Angle.)

Now, some of us are used to looking at the spin scan "peanut" which shows the pedal stroke. If you're not familiar, the little waistline in the middle is a representation of the diminished power at the back of the pedal stroke. If it were a perfect circle, that would show exactly even distribution of power, on both legs, through the duration of the pedal stroke. This doesn't really happen in real life, as far as we know!

FUN FACT! Thoughts about a peanut scan on flat pedals vs. clipless
What's interesting here is that this screengrab was done on an oval Qring on platform pedals on a bike that is normally used for demos & shows. Now, with platform pedals, it is not possible to exert a "pull" from the hamstring to have power on the back spot of the chainring. What we see here is the smoothing of the power over a wider range of the pedal stroke. On a round chainring, the peanut is more distinctly split. With a clipless pedal, you ostensibly could exert a pull up at the back of the pedal stroke & have a similar graph, but it's not possible with the flat pedals. So fascinating!

 So there you have it! Hit us up if you have more questions. infousa@rotorbike.com