Oval Chainrings Explained (Why You Need One!)

Words by: Reamonn Ryan

We recently put the Absolute Black oval chainring to the test against round chainrings and dove a bit further into this topic. Watch the video above or check out our recent article about oval chainrings vs round chainrings.

Have you noticed the growing popularity of oval chainrings or elliptical chainrings as some call them? Wondering what all the fuss is about? Well, look no further! We explain it for you. Right here, right now.

Simply put, the oval or “elliptical” chainring, helps maximize the power you personally put out when you are at an optimal part of your pedal stroke to lay it down and allow the bike to be a little easier to pedal when you are in the non-optimal part of your pedal stroke. To clear up any confusion, the chainring does not produce more power. It only allows you to optimize your true potential. Essentially, the oval chainring lets you work a little less but achieve a greater outcome.

The oval chainring design is intended to eliminate the uneven pedal stroke you may feel with a normal round chainring and also help reduce the amount of shifting you experience as you get more and more exhausted. Since the design has you working less, you have more energy to keep on going.

The most prominent chainrings with an oval design are produced by absoluteBLACK and Wolf Tooth, with SRAM quickly coming up. Although the designs are very different, they both serve their purpose. Wolftooth’s PowerTrac Elliptical™ (PTE) chainrings are slightly less Ovalized (10%) with (112°) timing. They “simply” put it as:

“With PowerTrac Elliptical rings, the larger-diameter section of the ring engages with the chain at the optimal point on the downstroke, or “Power Zone,” – between 1-5 and 7-11 on a clock face – to take advantage of your body’s natural biomechanical POWER: For example, during this section, a PTE 34t ring is equivalent to a 36t round ring. Similarly in the “Recovery Zone” (11-1 and 5-7), the smaller section on the PTE ring engages, maximizing EFFICIENCY in the weakest part of the pedal stroke; here the PTE 34t ring is equivalent to a 32t round ring.” – Wolf Tooth

On the other hand, absoluteBLACK has a bigger ovality with their Oval Chainrings. All Oval chainrings produced by absoluteBLACK were scientifically developed in their own state-of-the-art science laboratory in Slovenia led by a renowned biomechanist Dr. Borut Fonda. By testing several thousand people across all ability levels– from complete beginners to the recent Tour de France winner Tadej Pogačar and then utilizing that data, absoluteBLACK  designed oval chainrings that improve cycling performance by precisely increasing the chainring diameter at the point where the greatest forces are present and decreasing the chainring diameter when the pedals are over the top/bottom transition. They fit human pedaling motion perfectly and involve the hip joint to a larger extent, which takes the load off the knee, noticeably reducing knee pain if you suffer from it [with round rings].  With that, they have become one of, if not the most popular brand, engineering and producing Oval chainrings in the Bicycle industry. In their words:

“With absoluteBLACK oval chainrings, we demonstrated that cyclists exhibit 9% more effective pedal stroke by applying less force to the pedals that doesn’t contribute to power. Riders are simply applying less muscular force input for a given power output (vs round rings), or in other words, it allows them to pedal at higher power outputs with the same effort as with round rings before. It also results in improved efficiency, which is a metabolic measure (the ratio between the mechanical work and energy expenditure). We demonstrated that cyclists improve their efficiency when using absoluteBLACK oval chainrings.”

With that, they have also become one of, if not the most popular brand, engineering and producing Oval chainrings in the Bicycle industry. In their words:

“Our 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 a lot 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.” – absoluteBLACK

Without boring you on all the numbers and science behind why and how these do such a great job, we will just simply say that with the decreased amount of effort a rider gives and a more consistent pedal stroke lead to an overall more efficient ride. But wait! You may be asking yourself why does this really matter? Well, luckily the geniuses behind absoluteBLACK were more than happy to explain. In their own words:

“With oval rings, rear tire traction improves greatly on loose and slippery terrain. Smoother power delivery to your rear wheel means that you will be able to maintain better, constant cadence; get less stress on the joints (knees) and therefore be able to keep a certain level of effort for longer. This results in higher average speed. Moreover, 11 studies made by various Universities in the World show that using oval chainrings human legs utilize more muscle groups (compared to round one), but each of them to a lesser degree. Load from pedaling an oval chainring is spread over greater muscle mass which in effect gives you the feeling of fresher and more relaxed legs.” – absoluteBLACK

Ride Review:

All-around shredder and customer service champion, Logan Ammon has spent some time on an oval-ring to see exactly what the fuss was all about. This is what he had to say about his experience!

I have spent almost the last year riding with the oval chainring. At first, it felt a little awkward as my pedal stroke felt off but this feeling quickly faded after the first few minutes of climbing. After a couple rides, I really started to notice that on steep climbs where my legs would normally start to feel the burn were a little easier. While this didn’t make the big hills feel worlds easier, it definitely made a difference.

The biggest advantage to the oval ring I have found is climbing through technical sections. The ease of bringing the pedals back around to the optimal power zone. Making those technical climbs a bit easier.

If you are looking to try something new I would highly recommend an oval or elliptical chainring. Feels a little odd at first but after you get used to it, it makes a standard round ring feel outdated.

This article was written / authored by Reamonn Ryan. Reamonn has worked in the bicycle industry for 6 years now and currently runs our Instagram account along with testing products, editing video content, and writing blogs like this one you just read. Reamonn was a die hard BMX kid for over 10 years and once he started at Worldwide Cyclery made the switch to mountain bikes where he can send stuff better than most guys at the shop. If you like any of our Instagram posts or have gotten any responses from your DM's it was most likely from Reamonn, so give him a thanks. As with all of our employees, Reamonn is a key part of making Worldwide Cyclery the "Best Damn Bike Shop in the World".