 Do oval chainrings improve your performance or are they just another bike industry gimmick? Today I'll be jumping into the science on oval chainrings to answer this very question. I'll also touch on what company makes the best shaped oval rings, will oval chainrings save your knees, what styles of riding benefit the most from oval chainrings, and whether or not oval chainrings will screw up your power meter readings. Welcome back to another video. My name is Dylan and I'm a cycling coach at CTS. If you're new to this channel, I make weekly science-based training, racing, and gear related videos. If you want to learn how to get faster or just more about the science of training in general, then be sure to subscribe. And if you have a training question or a topic you'd like to see me cover in a future video, be sure to leave it down in the comments section below. I do my best to get to all the questions in the comments. So let's get this out of the way right off the bat. A lot of the science on oval chainrings isn't very high quality. Some of the studies aren't published or peer reviewed, and others are funded by oval chainring companies seeking to prove that their product works. Obviously they're not going to put out a study saying that their product doesn't work because that wouldn't be good for their bottom line. Okay guys, I've done some in-house scientific testing and drinking hypergain beast mode mass gain or raw addition in the cupcake flavor, increased study subjects FTP by 28% over not drinking. Anything for four days, link down in the description. Unfortunately, they don't always disclose this information either. So favorable results should very much be taken with a grain of salt. That being said, weak science is still better than personal anecdotes or a company's claims taken straight off their website. In this video I tried to stick mostly to published literature that didn't have any apparent conflicts of interest. However, I did take into consideration every study I could find to come to a final conclusion. Without further ado, let's jump into the science on whether or not oval chainrings will make you faster. This study on physiological responses of riding with oval rings tested round rings versus the rotor Q-ring by having subjects perform two incremental maximal tests, one on each ring. The results, although maximal power was higher with the Q-rings, the results were not statistically significant. In a test of repeated 20 second sprints, again the Q-rings performed better, but the results weren't significant. And there's certainly plenty of studies that echo this conclusion. This study on various types of chainrings tested round, Shimano biopace, and an engineered ellipse. They found that gross efficiency was not improved by these designs. This study using a harmonic chainring or osometric design found that even though the ring was based on optimization analysis of pedaling, this did not translate into an advantage over round rings. However, for every study showing no advantage of oval chainrings, it seems that there are just as many that do show a benefit. This study testing osometric chainrings had subjects perform two incremental max tests with and without oval rings. They found that maximal aerobic power was higher when using the oval rings. When you get into these studies that show favorable results though, it's important to look out for industry bias because a company has a lot to gain by funding a study that shows that their product works. For what it's worth, the study's authors claim there were no conflicts of interest, although one major flaw of the study was that it was done on non-cyclists and the study even stated that they can't generalize these findings to well-trained cyclists. However, this isn't the only study showing a benefit to oval rings. This study that used well-trained cyclists found that it significantly increased performance in a one kilometer effort. Interestingly enough, this study testing osometric rings found no difference in muscle activation at higher cadences of 90 to 110 rpm but did find enhanced muscle activation at 70 rpm, suggesting that maybe oval rings are better at lower cadences. This is funny because one of the most notable osometric chainring users is Chris Froome and he's definitely a high cadence guy. I don't have time in this video to cover every study done on oval chainrings but I will tell you that the results are very mixed and there seems to be no consensus about whether or not they work. In all the studies that I looked at for this video and I put studies and quotations because some of them were just unpublished papers, eight showed that oval chainrings did show a benefit and nine showed that they showed no benefit. So what exactly is the reason for this discrepancy? Some of it may be due to factors that I've already talked about like industry bias or poor study design but we also can't rule out the placebo effect. Just thinking something will work will often make it true. In the case of oval chainrings, subjects may assume that they'll be able to perform better with oval rings and this belief is enough to produce a favorable result. On top of this, not all oval rings are created equal. Anyone who lived through the Shimano biopace era knows how much of a disaster that was. Oval chainrings have come a long way since then but there may still be some work that needs to be done. For example, this study on the effect of oval chainring ovality on power tested round rings versus rotor Q rings versus osometric rings. They found that the most pronounced non-circular chainring or the osometric ring evoked systematic alterations of joint specific relative sagittal joint power contribution. Basically the oval shape needs to be pretty pronounced for it to have any potential effect. From this paper comparing the biomechanics of every non-round chainring design using a mathematical model we can see that the osometric ring is close to the top performing ring and is actually the best performing commercially available ring while the rotor Q ring is close to the bottom just above biopace. The reason they cited was the lack of ovality and the orientation. In fact the best performing ring was the hull oval which has such an extreme ovality that it becomes problematic for actual practical use and the ring is not commercially available. It's important to point out that these were the results of a mathematical model and in real world testing even the osometric ring has mixed results as we've seen. But it could very well be possible that to get any effect out of oval chainrings the oval needs to be so extreme that you can't actually use it in any real world application. After all front shifting with oval rings is already compromised with the current light ovals. All of this being said there is one area that I found that oval chainrings kept showing a benefit for in the literature and that is sprinting performance. Remember in the first study I said that oval rings improve sprinting performance but the results weren't significant. Well there are studies out there that test sprinting performance with oval chainrings that do have significant results. For example this study on the effects of non-circular chainrings on sprinting performance used train cyclists to test osometric rings versus round rings in a max sprint. What they found was that the max power was greater with the oval rings by about four percent. Although it's important to note that they acknowledge and thank the osometric company for providing rings for the study which could lead to bias. Osometric certainly didn't let them use the rings with the intention of them showing that they didn't work. There are also two studies done on BMX racers using Q-rings both done on the Spanish national BMX team and both found improvements in start acceleration using the rings but only in the elite group interestingly enough. One concluded that the rings improve performance provided that the riders have a condition level enough to ensure the capacity to develop pedaling properly despite the strength needed. At best I would say that the evidence that oval chainrings improve sprinting performance is a little bit stronger than at lower intensities however the number of studies is limited so certainly more work needs to be done here. Another reason why people may choose to use oval rings is to reduce strain on the knees and I did find one study that addressed this. This study used osometric rings and found no difference between oval and round rings in patello for moral loading which shows a clear link with knee pain. Granted this is just one study and somebody in the comments is probably going to talk about how oval chainrings save their knees and now they can ride again. Certainly don't let me take that away from you and if that is the case then keep using oval chainrings. To throw another wrench in the spokes of oval chainrings some people have found that oval chainrings may inflate power readings on crank based power meters so if you purchase oval chainrings and you see an increase in power it may just be the rings giving you false numbers. Some people have found this inflation to be 2.7 to 4 percent. Well that sounds like the perfect product to give me an edge on Zwift this winter. I'll take five. Given the overall weak evidence that oval chainrings improve performance this fact alone is enough for me to steer clear of them. I did used to use oval chainrings a couple years ago and I didn't really see any performance benefit. In fact the year after when I switched around rings I had one of my best seasons ever. There are way too many variables here for me to give credit to the rings but this combined with the inconclusive research on oval chainrings was enough for me to give up on them. Mountain bikers who use oval chainrings often state that they are able to put out more even power and therefore not lose traction when climbing. There are currently no studies investigating this so I can't confirm or deny this. The available science that we have on oval chainrings is pretty evenly split and a lot of the studies that do show benefits often have industry bias. For sprinters the balance of evidence is in favor of using oval chainrings however this is based on only a few studies. Dylan let me stop you right there I got two words for you. Chris Froome checkmate. Some high-profile riders namely Chris Froome and Bradley Wiggins have used osometric rings to win some pretty big races like the Torr and if there's any oval chainring that might work it's probably osometric since the oval is more pronounced than other companies like rotor or absolute black for example. However interestingly enough Team Ineos doesn't have all their riders using these rings which you'd think that they would if they believed that there was an actual benefit to them and on top of this most of the Pro Peloton is content with just sticking with round rings. This certainly isn't evidence in itself just because a pro does something doesn't mean it's the right thing to do but it is another piece of the puzzle that will lead to my final recommendation on oval chainrings. If you like using oval chainrings then keep on using them if you don't have them on your bike then save your money and stick to round rings because they probably won't make you any quicker. Thanks for watching I hope you guys found this information helpful if you like this video be sure to give it a like share it with a friend and subscribe and if you want to be notified every time I put out a video be sure to hit the notification bell as well. If you're looking for a coach if you sign up through CTS be sure to use my code CTSDJ to save $40 by waiving the registration fee details are down in the description.