Non-circular chain-rings felt awesome at the first go!

The first impression from riding the oval chain-rings is that pedaling feels much smoother, which is exactly the opposite of what I expected. It is true there needs to be some adjusting, but my perception is that the ovality of the rings almost forces the pedaling circle to be ‘rounder’ and therefore more efficient – thumbs up. I felt stronger, which is a second perceived benefit from using the rings.

The idea behind non-circular rings is that it maximizes the part of the pedaling circle where most power is produced (larger part of the ring = using a large ring) and minimizes effort on the dead-spot part of the pedaling circle (smaller part of the ring = similar to using a smaller ring). In the example below a picture of a 52T non-circular chain-ring ranging in size between that of a 48T to that of a 56T (correspondence will depend on the degree of ovality). Knowing that and having experimenting it, it makes me wonder why isn’t everyone around using them. There could be some drawbacks, I have seen cases where adaption to the front derailleur was necessary, therefore the installation and shift tuning does not seem completely agreeable with every single set-up out there.  Also, a major drawback is the price, a set of new rings could easily cost in excess of USD 280, although with the increased popularity there are newer brands at more affordable prices.

oval ring example

BENEFITS: more efficient pedaling (lower oxygen consumption, lower lactic acid build-up, lower heart heart); angle customization (in some models)

DRAWBACK: disbursement on new rings; seamless shift tuning might be difficult or even require adaption of the front derailleur in some cases


Osymetric USA ( – claims power gains of 7 to 10% in watts and 10% reduction in lactic acid build-up. The site brings a few studies comparing round to non-round rings in terms of: aerobic metabolism, hill climbing, power and others. Retail suggested price on Osymmetric´s site is USD 149.99 for an Outer 52 teeth ring and USD 139.99 for an inner ring (38 teeth).

ROTOR Bike Components ( – The Spanish company launched its oval Q-rings in 2005. According to the company they seek ultralight weight products with balanced rigidity. Rotor affirms QXL model tests show 1.6sec gain in a 1km TT by elite rider, compared to a gain of 1.6 to 1.8sec of 60mm aero wheels. Besides the ovality of the ring customization is possible via OCP (optimum chainring position) to 4 different settings, to better suit each riders style and riding situations. Prices on R&A Cycles range between USD 149 to USD 188 for an outer ring and around USD 90 for an inner ring.


Ogival, Le Plateau de Bernard Hinault, was made especially famous after rider Mass van Beek beat the world hour record using a 70 teeth ring, according to ( The radical ‘eye’ shape is noticeable from a far and will certainly make a conversation topic in the group rides. The site of the brand ( has some interesting videos in French, I was impressed with the ‘Les Plateaux Ovalises à la Loupe’ where the smoothness of the circular motion is demonstrated for the Ogival against other non-circular rings (Biopace Shimano, Polchlopeck, harmonic, and Stern). A single road ring on their site goes from around EUR 70 to EUR 117.

noncircular rings comp


Doval – this is a Korean brand ( which offers a series of models for MTB and speed, road and aero, and include a MicroOCP with 5 tuning stages, being 1 with the lowest riding inertia (similar increasing the angle of the saddle), and 5 with the highest riding inertia (similar to reducing saddle angle – similar to triathlon and TT positions – recruiting posterior leg muscles). At Amazon UK website a pair will sell for  GBP 99 and on eBay I have found a single ring for about EUR 30. This is the brand I bought and currently use, mainly because of affordability. I first used a pair of 52\39 which I mounted on my TT bike and recently swapped for a 54\40 pair.

Absolute Black – ( They offer a wide range of MTB and road chainrings starting at around USD 55. The aero 50T chainring will set you back USD 165.

Dual-Oval– ( French designed non-circular chain-rings with 3 stages micro OCP settings. Regular price for a kit is around EUR 115 on the company’s website.

Proval Bike Components – brand of recordist time-trialist Maas van Beek. ( Have not found much pricing and availability information, although there are distributors listed. The company advertises outer rings as large as 54T with a 25% ovality which yields an equivalent to a circular ring of more than 60T.


Chain Reaction Cycles put the Absolute Black MTB chainring to the test:

As always, GCN has a good video about everything regarding cycling:


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