Redux: Osymetric Chain Rings

By: James Morrison Aug 8

Share |

Classic cycling pedagogy teaches us to try to pedal in perfect circles, which are found nowhere in nature. Look at a horse or a cheetah running, or for that matter look at the cam pumping on an oil well: there is an asymmetrical motion at work that creates greater leverage on one side of the stride, or stroke, than on the other. Osymetric rings are designed around the idea that your leg muscles are better at pushing than pulling; so if the pedaling motion can be taylored to used the pushing muscles more than the pulling muscles, your legs will fatigue less quickly and you will go faster. Sometimes the simplest arguments are the most convincing, and we're buying what we're selling here, so to speak. We like the rings, we race them, and our guess is that most of you will like them, too.

If you look long enough on the Internet, you can find an opinion on just about anything. Digging around online for information on Osymetric chainrings is a classic example of the misinformation mill at work, so we thought we should offer some of our own experience here in an effort to provide the interested reader with some information on what Osymetric rings are, and what they are not. Several of our team riders have recently started using the rings for training and racing, and as a result of our overwhelmingly positive collective impressions, we have decided to start selling the rings in our store.

What The Rings Are:

  • - An asymmetrical, squashed oval shape.
  • - A means to employ a longer, more powerful lever to turn the gears on a bicycle drivetrain.
  • - Funny to look at.
  • - Odd feeling to pedal, for the first 2-3 rides, unnoticeable after that.
  • - Used by world class athletes, on teams like Garmin-Cervelo and Team Sky to win the world's biggest races, like the Critérium du Dauphiné, Criterium International, Paris-Nice, ENECO Tour, and stages of the Giro D'Italia and the overall in the Tour De France.
  • - Not officially endorsed by anyone: the athletes who chose to use Osymetric rings pay for them.
  • - Easy enough to set up, though depending on frame geometry, bottom bracket spacing and other factors, they can be finicky and require some fine-tuning.

What The Rings Are Not:

  • - The same thing as Bio-pace or Rotor rings.
  • - A gimmick.
  • - For everybody.
  • - Particularly hard to get used to.
  • - Awkward feeling after the first ride or two.
  • - Always difficult to set up: on a lot of bikes, they dial in perfectly at the first attempt.
  • - Likely to make your legs tired all the time. Remember, just because the rings allow you to pedal harder, doesn't mean you have to.

If you take a look at the Osymetric USA website you can find a number of studies done in various sports medicine laboratories that all make claims of measurable increases in power for the same perceived exertion and heart rate when using Osymetric rings as opposed to round rings. What we know here at Embrocation is that using a longer lever generates more force than using a short one. When you adapt to riding Osymetric rings, you will notice a definite increase in your ability to climb out of the saddle, as well as push a big gear either uphill or on the flats. Our anecdotal experience has been that the benefits of the rings are less noticeable at higher cadences, when leverage and torque are not as much of a factor.

One of the most common misconceptions about Osymetric rings is that they are the same thing as the old Shimano Bio-pace design, or the currently popular Rotor rings. They are dramatically different in both cases, and here's how:

Bio-pace was simply a bad idea. They were, in oversimplified terms, almost a reverse design compared to Osymetric. What Bio-pace did was to shrink the size of the gear ratio through the power phase of your pedal stroke, making it easier to pedal, but also generating less power, which is entirely counterproductive. Rotor rings, on the other hand, do offer a slight increase in gear ratio through the power phase of the pedal stroke, but they are essentially simply round rings with an extra tooth at 12 o'clock and 6 o'clock. This gives you some extra leverage where you need it, but it noticeably does not shrink the gear ratio through the deadspot of the stroke, which means you are still using those pesky pulling muscles more than you should have to.

A word of warning to address another common concern about the rings: yes, it turns out that having your legs locked and loaded, ready to fire at full force at the apex of every pedal stroke, does in fact make it easy to ride harder than you intend to. We have noticed that on first adjusting to the rings, many riders have a tendency to ride tempo everywhere they go, and mash big gears uphill because the can, and it feels good. Sure enough, this will make your legs tired, so feel free to take recovery rides when you need to; it is just as easy to spin at a nice high cadence on Osymetric rings as on round rings, and you'll go faster. And remember too that the gearing may look funny to you at first: pedaling an optimized 42 tooth inner ring won't likely bother you uphill, but it does mean that your easy gear for a recovery spin at 15mph is now more likely to be 42x21 or 42x19, as opposed to riding in the 16 or 15 cog as you would likely do for a casual spin with a standard 39 toothed round ring.

The final bugbear that you are likely to hear about if you go looking for consumer opinions on Osymetric rings is front derailleur adjustment issues. Yes, the front derailleur setup can be finicky, but as a rule it is nothing that minor adjustments won't address. Each set of rings comes with a set of washers to spread the front derailleur cage, if need be, and a set of step-by-step photographic instructions to help walk you through the process. Osymetic USA is also working on a series of instructional YouTube videos that customers can use as a reference, and based on our own experience and that of people we know, the attention to detail required in adjusting the shifting is worth it.

Osymetric Chainring Set - $299

Select Chainring Configuration -

Images by Jeremy Jo



© Copyright 2013 - Embrocation Cycling, INC