Lowdown: absoluteBLACK Oval Traction Chainring

While claims about the advantages of non-round chainrings are hard to substantiate, they do help some riders decrease strain on knees, increase traction, and smooth out their pedal stroke. Keep reading to learn more.

Weight: 55 grams (30T)Price: $66
Stat Box
[TD] Options: 28, 30, 32, 34t, black and racing red[/TD]
[TD] Rating:
4.5 Flamin' Chili Peppers
4.5 Chilis-out-of-5[/TD]


  • 10-, 11- and 12-speed compatible
  • Oval rings not for everyone
  • Can be exchanged for round rings w/in 30days
  • Boost, BB30, GXP, e*thirteen, Cannondale, RaceFace, Shimano compatible
  • Oval rings can help riders w/knee issues

Review: absoluteBLACK Oval Traction Chainring

Ovalized chainrings have been around for a long time. There are lots of options on the market for mountain, cross, and road bikes. And in case you missed it, a certain Chris Froome just won the Tour de France on a set of the radically shaped Osymetric rings.

Shown here is the ring clocked for maximum power output. The ring is effectively a couple teeth larger (taller) at this point in the pedal stroke.

Shown here is the ring clocked for maximum power output. The ring is effectively a couple teeth larger (taller) at this point in the pedal stroke.​

As a mechanic I was initially skeptical of oval rings, as early attempts led to poor front shifting. But with more refinement, and now the advent of the single chainring mountain bike drivetrains, ovalized rings are becoming more and more popular.

I began experimenting with non-round rings after years of suffering from knee issues, and the results were good. I can't attribute my recent pain free cycling entirely to these rings, but I do think they helped me on the road to recovery. I feel a lot better on the bike than I have in a long time.

Here's the gist of oval rings: Once mounted they make your gear larger in areas of the pedal stroke where you can apply the most power. Simultaneously, they decrease the size of your gear when in the dead spot of your pedal stroke. From what people smarter than me have explained, it appears the science is sound. No one has a perfect pedal stroke where pressure is applied evenly throughout a given rotation. Or to put it another way, oval rings are designed with a fallible human power source in mind.

This is how absoluteBLACK spins it: "Our traction Oval chainrings work because a rider does not produce power evenly through a pedal stroke; they maximize the part of the stroke where power is produced and minimize resistance where it isn't. Oval rings make the spin cycle smoother and are easier on legs while climbing. Believe it (or not), but a round chainring doesn't transfer torque to your rear wheel as smoothly as an Oval one. You will actually feel your stroke to be more "round" with an Oval shape than with a round chainring. Smoother power delivery to your rear wheel means that you will be able to maintain better, constant cadence, have less stress on the joints (knees), and therefore be able to keep certain level of effort for longer."

A close up of the ring, showing it at its taller and therefore largest development.

A close up of the ring, showing it at its taller and therefore largest.​

Mounting an absoluteBLACK Oval Traction ring on my mountain bike was an experiment. I wasn't sure about it for off-road purposes, but the claims of increased traction had me curious. And I have to say that at the very least, power and traction have not decreased. The profile, that is the placement of the oval shape in the pedal stroke, is seamless. You simply don't notice any difference after a few rides.

It's when riding easily that you might feel some pulsing in the delivery of power. Cruise around your block and you may feel the resistance drop away as the ring phases to its smaller diameter. With the bike in a workstand you can also feel the changes as you pedal.

But under load, especially on hard uphills, I don't feel the oval profile at all. This is a very good thing. The ring isn't any louder than a standard round ring either. Pedaling along on a flat section of trail, the ring feels normal as well. This may be because I've ridden oval rings on the road before, but other riders I know on oval rings express similar experiences. There is no pulsing or jerky feel to the drivetrain. I experienced no change in rear shifting performance either.

It's hard to quantify an increase in traction and especially difficult to attribute it to the absoluteBLACK chainring. But I'm inclined to believe the company's benefit claims. Often a loss in traction is due to a spike in power delivery. Smoothing out the delivery is precisely what these oval rings do.

AbsoluteBLACK changes the placement of the oval based on the chainring size, ensuring that power output and traction are optimized no matter the ring. Unlike Rotor chainrings that are fitted to an existing spider using a series of mounting points, you cannot adjust the placement of the ovalization on absoluteBLACK's Oval Traction rings. There is only one way to install them and so only one way for the timing of the chainring to function. But again, it appears the British firm has done its homework.

Conversely, the ring becomes a couple teeth smaller during the phase of a pedal stroke where a rider can develop the least amount of power.

Conversely, the ring becomes a couple teeth smaller during the phase of a pedal stroke where a rider puts out the least amount of power.​

The construction of the ring is exceptional. AbsoluteBLACK uses 7005-series aluminum. Installation was easy with the spline a perfect fit for the SRAM crank arms. This should come as no surprise, but the wide narrow tooth profile worked well in all conditions.

To aid with chain retention absoluteBLACK also sent along its new Oval Chainguide. While I've rarely dropped my chain while using a wide/narrow ring and clutch type rear derailleur, the $60 guide does add some peace of mind that is hard to beat.

I've now had the absoluteBLACK Oval Traction ring on my bike for over two months. My knees feel great and the ring has showed very little wear. I don't see myself taking it off for the foreseeable future. For me, there is no downside, only happy mountain biking.

At $66, the price of the Oval Traction ring is very competitive. It's actually cheaper than a replacement SRAM ring, making trying an oval ring even more attractive. AbsoluteBLACK also offers a 30-day trial period on its oval rings. If you don't like it, they'll replace it with a round ring. So you're saving money and getting a chance to help your knees and potentially increase power and traction while mountain biking. Sounds like a win-win to this tester.

For more info please visit absoluteblack.cc.