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Maybe you’ve heard of oval chainrings but you’re not entirely sure what all the fuss is about. A good number of brands now offer ovals and we’ve seen uptake across disciplines, from Pro Tour road cycling to the upper echelons of the Enduro World Series. Oval chainrings essentially require less effort to drive than traditional round ones, tempting us with prospects of marginal gains. But why is this? And how ‘oval’ does it need to be? And what size oval should you get if you make the change? All of these questions and more are answered below by the industry experts absoluteBLACK, ROTOR Bike and Wolf Tooth Components.

Why is it less effort to drive an oval chainring compared to a round one?

ONEUP COMPONENTS: It isn’t. Sorry to disappoint. There are lots of biomechanics studies investigating the benefits of oval and other non-circular chainrings for road biking. Almost all of them focus on power gains. The reality is that the power advantages of oval rings are so minute that they can only be measured with elite level professional athletes on a turbo trainer or test track.

For mountain biking the real benefit is increased climbing traction. To paint a picture of the usage, most mountain bikes do not have a low enough gear to be able to ‘spin’ up steep loose grades.  The pedaling motion therefore becomes very biased to powerful, sometimes out-of-saddle, downward thrusts.  A portion of the momentum is used to help carry the pedals over TDC and the cycle starts again.  The oval ring therefore ‘smooths’ the torque delivered to the ground and allows the rider to maintain traction. Increased traction means less wasted energy used to throw rocks at your riding buddies.

Regarding power meters it is important to account for the bloated numbers that you’ll see when using an event-based system (most crank/pedal/chainring power meters).

ROTOR: The oval (as positioned by Rotor’s Optimal Chainring Position) reduces the amount of effort required in the weak (back) part of the pedal stroke, and allows the rider to maximize the stronger part of the pedal stroke.

absoluteBLACK: The human body uses skeletal muscles to generate force on the pedals, predominantly during the downstroke. Each skeletal muscle has a unique characteristic that doesn’t allow even muscular force throughout its contraction. For example, peak joint power from the knee occurs at around 70 degrees crank angle (0 is at 12 o’clock), whilst the hip peaks well beyond 90 degrees crank angle. Further adding ankle joint power, angular velocity of the crank, inertia of the leg and the force effectiveness, which is how much of the force generated of the muscles is actually transferred to power, we can see that a power profile throughout a crank cycle is not even, but peaks somewhere around 110 degrees of crank cycle (normal road cycling, for example). AbsoluteBLACK oval chainrings are designed to perfectly fit a specific riding style and involve the hip joint to a larger extent, which essentially takes the load off the knee and adds to muscular efficiency. AbsoluteBLACK oval chainrings’ major axis orientation, that is when the chainring’s diameter is the largest, matches the power profile of a cyclist to reduce power losses and transfers the load from the knee to the hip. This was established based on several thousand measurements using one of a kind diagnostic equipment to measure 3D pedal forces and joint loading. Measurements were carried out on thousands of recreational road & mtb riders and hundreds of professional riders, including the entire Pro Tour Team UAE where we officially deliver our scientific biomechanical optimization services with our Science Lab. With such a wealth of data we are able to precisely design the chainrings that are able to increase the mechanical effectiveness  – which means you perceive it as having less effort going at the same speed compared to round.

Wolf Tooth Components: Short answer: Oval chainrings synchronize pedaling with the biomechanics of the human body. These chainrings provide lower gearing in crank arm positions where you can’t generate as much power and higher gearing in positions where you can generate more power.

Longer answer: Wolf Tooth elliptical chainrings are designed to synchronize pedaling with the biomechanics of the human body and the geometry of crank arms. When the crank arms are near vertical you have less leverage and you are using smaller muscles to apply power to the crank arm. To compensate for that, we designed the chainring to effectively be two-teeth smaller in these orientations where you can’t generate as much power. Conversely, when the crank arms are near horizontal you have much more leverage and you can take full advantage of your quads to apply much more power to the crank arm. To compensate for that we designed the chainring to effectively be two-teeth bigger in these orientations where you can generate more power. So if you have a 32 tooth elliptical chainring it will feel like a 30 tooth chainring when your cranks are near vertical and a 34 tooth chainring when your cranks are near horizontal.

Will my chain have a greater tendency to drop if I use an oval chainring?

ONEUP COMPONENTS: No. We use the same tooth profile on our oval and round rings.  Both offer extremely effective chain retention. Our new 12 speed Shimano HG+ rings are available now.

ROTOR: Shift performance can be impacted depending on specific drivetrain, front derailleur setup, frame geometry, and other factors. Mechanics experienced with ovals can diminish any negative inclination toward dropped chains, however.

absoluteBLACK: No. If we compare an aB round to oval narrow-wide ring there is absolutely no difference in the chain retention capabilities. But there is a difference among brands (regardless of the chainring shape). This is because every brand has designed the teeth differently and they will behave in a different way when they wear out a little or you use them in the mud.

Wolf Tooth Components: No. Chain retention has nothing to do with chainring shape. Chain retention is all about making sure the chain stays aligned to the chainring while you are pedaling. This is accomplished by designing chainring teeth to self-align to the chain, minimizing how much the chain bounces (i.e. clutched rear derailleurs), or with mechanical chainguides to force alignment. (On a wide/narrow chainring, every tooth on the chainring aligns the chain with the chainring which makes them significantly better than non-wide/narrow chainrings where the chain is only guided by the narrow links in the chain).

Are there any chain devices specific to oval chainrings?

ONEUP COMPONENTS: Yes, OneUp was the first company to design a chainguide specifically around an oval chainring.  These were designed concurrently and launched in 2015.  The OneUp V2 Chain guide allows for more extreme ovalities and simplifies height adjustment.

Wolf Tooth Components: Yes, certain chainguides like the Wolf Tooth GnarWolf are designed specifically to have enough overlap to ensure the chain properly meshes with the chainring at both the largest and smallest diameters of and oval chainring.

absoluteBLACK: Yes. absoluteBLACK offers a full range to fit all major frame mounting systems. The difference is mainly in the cage itself. It has to be taller and profiled differently to be able to cope with variable shape of the chainring.

Can I increase the size of the chainring I run if I use an oval one?

ONEUP COMPONENTS: No. Oval rings do not give the rider superpowers (or any extra power for that matter).  As such, we recommend sticking with the same size.

ROTOR: You can do anything you want! However, we recommend people stay with their original ring size, since using a Qring is about reducing the dead spot in the rider’s pedal stroke. Some riders do find that they are comfortable pushing a bigger gear with the diminishing of time spent at the back of the pedals stroke, but that’s individual preference.

absoluteBLACK: Yes and no. We always recommend swapping like for like, so if you have a 32T round ring at the moment, you should consider getting a 32T oval. The same applies to our shiftable road oval chainrings. This recommendation is based of course on the assumption that the current round chainring is of the right size for your riding style and abilities. If you feel currently that your round chainring is too big or too small then reduce/increase the size of an oval in the same way as you would with the round ring.

Wolf Tooth Components: It depends. One pedal revolution with a 32T round chainring will get you exactly the same distance as one pedal revolution of with a 32T elliptical chainring, so if you pick your chainring size to make sure you never spin out in your biggest gear, we generally recommend using the same size chainring for both round or oval. However, since many people select their chainring size to be small enough to provide the low gearing they need to get up the steepest climb they encounter on their ride (and that is ultimately determined by having enough power to make it through the weakest part of their pedal stroke) many people are comfortable using a oval chainring that is two-teeth bigger than the size they would pick if they were using a round ring.

Will my chain wear faster or slower with an oval chainring?

ONEUP COMPONENTS: No. Oval rings do not contribute to additional wear. Though it should be noted that at extreme chain angles as viewed from the drive-side of the bike, (ie. The angle between the upper and lower chain lengths like when pedalling in the largest cassette cog), the rear derailleur cage will move thereby adding wear to the derailleur clutch.  This is relatively minor compared with the amount of normal clutch movement.

ROTOR: Should be exactly the same. It’s the same gear inches.

absoluteBLACK: Our oval chainrings are designed in a way that they always pull the same amount of chain at any position of the crank rotation. Imagine an ellipse which you can cut through the center at any place and it will always produce equal halves. The same is true for the circle. Because of this, chain wears in the same way as with the round chainring. It goes without saying that the best way to increase the life of any chain-chainring combination is to lube the chain regularly and keep it clean.

Wolf Tooth Components: No. Chain wear is determined mainly by factors like how well your chain is lubricated, how much dirt and grit gets on your chain, how much power to apply, and how much time is spent in cross chained gears. If anything, elliptical evens out the variation in power that gets applied to the chain during a pedal revolution so there is less cyclical loading of the chain which could actually extend the life a tiny amount.

How ovalized does the chainring need to be, in order to be effective?

ONEUP COMPONENTS: The effect is proportional traction-wise but in our testing, we found other constraints limit the ovality. We choose 12% and 115° clocking and detune that to 10.5% on the 34T and 36T for better MTB chainstay clearance. When you get as high as 14% or 15% riders started commenting that out of saddle efforts felt inconsistent especially when navigating downhill trail features.

ROTOR: ROTOR has made rings varying in ovality from 10% to 16%. After extensive testing, we adjusted all rings to 12.5% ovality for best rider biomechanics.

absoluteBLACK: This is an interesting question without a definite answer. Our testing, that I mentioned above, revealed that somewhere between 8% and 14% yields an optimal result. But it very much depends upon the riding profile (e.g. road vs. MTB), chainring size, cadence and many other factors. We have optimized every chainring size and type to achieve the best possible result.

Our collected data on thousands of riders clearly show riders behave differently using different chainring sizes and riding different types of bike. To give you an idea, there is a very strong reason why someone is using a 36T chainring where someone else, in the same terrain, would use a 28T. Are these two hypothetical riders of the same level of fitness? Would they have the same power output, cadence, lactate threshold, body type or oxygen consumption?

But this is only part of the picture. The most important aspect in the oval chainring design is not only the ovality, but also the actual chainring shape and timing of the biggest radius of the chainring vs the crank arm. We optimize all of this per chainring size and type. Only then can we ensure a smoother and more effective pedal stroke that we are able to prove scientifically.

Wolf Tooth Components: There are lots of varying opinions on this and it probably varies a bit from person to person depending on bike and body geometry. Wolf Tooth chose 10% ovality to provide a meaningful amount of biomechanical benefit without being so extreme that it feels like you are pedaling squares.

How does an oval chainring effect the anti-squat of a full suspension mountain bike?

ONEUP COMPONENTS: The change is negligible.  In the power stroke you have a larger diameter but also lower chain force.  It is more notable that you’ve smoothed out your pedal stroke so should be feeling less bob.

ROTOR: The oval adds leverage to the rear dropout, depending on the chain’s placement in the gearstack. On anti-squat systems such as DW, the oval could feasibly add to the anti-squat platform. This would be notably untrue on a high-pivot or idler system, as they would negate the added extra torque, driving the wheel into the ground, potential for the oval.

absoluteBLACK: Excellent question. With a properly designed oval chainring you are achieving a smoother pedal stroke. That means you smoothen out the peak forces when you pedal. It can be nicely observed when going uphill. You would notice much better rear wheel traction on loose terrain. This effect also translates to much smaller pedal bob during riding, which properly designed anti squat is aiming to remove. Therefore simply going oval reduces the pedal bob and improves your effectiveness regardless of the frame construction.

Wolf Tooth Components: Anti-squat varies while pedaling with an oval ring, compared to the constant anti-squat found with a round chainring. You’ll find a much stronger fluctuation in anti-squat based on what cassette cog the chain is in than you would with an oval chainring. With everything else happening on a full-sus bike as you ride, this isn’t likely noticeable.

Will an oval chainring change the amount of pedal kick back experienced by a rider when descending on a full suspension mountain bike?

ONEUP COMPONENTS: Again, the effect is pretty negligible

ROTOR: Not really, because the pedal kickback is related to the squat system, and when descending, the rider is generally not engaging the drivetrain, which is where the oval can be beneficial.

absoluteBLACK: No. This only depends on the size of the chainring and frame construction since the chainring is not in motion.

Wolf Tooth Components: Pedal kick back varies while pedaling with an oval ring, compared to the constant pedal kickback found with a round chainring. With everything else happening on a full-sus bike as you ride, this isn’t likely noticeable.

Thank you to Borut Fonda, lead Scientist at the absoluteBLACK Lab, Lori Barrett at ROTOR, Kurt Stafki at Wolf Tooth Components, and Jon Staples at OneUp for contributing to this week’s AASQ. Got a question of your own? Click here to use the AASQ form to submit questions on any cycling-related topic of your choice, and we’ll get the experts to answer them for you!

40 COMMENTS

    • Well, for the sake of argument, what’s best for a pro who’s spent a gazillion hours learning to be smooth on round rings may not be best for a recreational cyclist.

      I put AB ovals on my gravel bike. I can’t say objectively if they’re better or worse than round, but I like how they feel. The biggest difference I notice is climbing standing which feels smoother.

  1. “AbsoluteBLACK oval chainrings are designed to perfectly fit a specific riding style”

    So what “specific riding style” are they designing for here? Mashers? Spinners? Flamenco?

    They sort of address this in the answer to the question about how ovalized a chainring needs to be, but specifics would be appreciated.

  2. I’ve ridden ovals. It felt like something was broken on the bike. Weren’t there a series of lawsuits about alleged knee injuries against a Japanese company roughly thirty-five years ago?

    • Here we go again… The Shimano Biopace rings were effectively doing the opposite of what modern oval rings do. It simply made no sense at all. Modern oval rings will smooth out the pedal stroke for many people. If it has any performance benefit, is debatable. But for many it will simply feel better, which imo is a bigger gain than a lot of “2% stiffer” products you can have.

  3. I’ve been running ovals on my SS for years, perfect for that super slow cadence climb that gets harder with every lap. Ive never felt the need on a geary though as you tend to have enough gears to spin it up.

  4. Didn’t answer the main thing keeping me away from oval: how it interacts with clutch rear derailleurs. There’s a video by LoveMTB in which he suspects the oval ring did something negative to his drivetrain. I forgot the details.

    • I also worried about an oval being less smooth to the drivetrain, and wondered if I’d see the rear cage moving more with each pedal stroke. It didn’t. Then I thought about it, and realized a couple of things. One is that these oval rings are perfectly symmetric — any way you cut them in half through the center, the same number of teeth are on each side. This means that the number of teeth engaging the chain does not change as it rotates. The other point is that these are designed to smooth out torque delivery, not make it worse. I’ve got a clutch derailleur on my bike with ovals and have had no issues.

      • Unfortunately that doesn’t pan out. I believe it technically would be true if the cog was an infinite distance away and therefore the top and bottom spans of chain were essentially parallel no matter what, but in the real world the chain wraps more (or less) than 180 degrees around the chainring, and tie amount of wrap will vary depending on the oval ring orientation. It absolutely (pun intended) does rhythmically pull the pulley cage back and forth.
        With that, I believe that oval rings coupled with a clutch derailleur inherently increase friction. I’d love Friction Facts or Zero Friction Cycling to test this.

        • Greg,
          I hope I cleared most of your doubts in the comment I directed to Varaxis. But I would like to comment on friction as well. What happens on the untensioned portion of the chain (portion that returns to the cassette through pulleys) has no meaningful friction implications for forward bike movement. Friction is measured only on the top part of the chain as when chain is under tension. This is where friction is coming from and it can be reduced by great deal with good chain and great lube. It also depends on the size of the chainring and cassette cog you use at that moment in time and also what is your cross chaining – which comes back to correctly sized front chainring to your terrain. If your chainring is too big and you are forced to use most of your time upper half of the cassette then this is where massive friction will come from. It also depends on the chain length – too short and big friction is inevitable. Rear cage is only serving two main purposes – to keep some tension on lower portion of the chain so you dont loose it off the chainring and to adjust for gear changes (chain length).

    • Hi Varaxis,
      If the oval chainring is designed correctly the movement of the derailleur cage is minimal and within a designed “play” of the clutch itself. We have spent a long time to make it right. For some this may seem hard to understand not seeing it in real life. When pedaling on aB oval chainring you see the chain is going up and down, but the real chain “feed” is constant. So the tension on the chain returning to the pulleys is also constant. Some riders may report a slightly bigger movement simply because chainring was not mounted 100% centrally. Many lower end cranks have usually bigger mounting tolerances and they may allow to mount the ring slightly off center. If you see that cage is moving more than 1-2mm then you just need to remount the chainring again trying not to push the ring on any side. If you have a 4 bolt rings you just need to loose the bolts a little bit then pedal on the stand and chainring will align itself. Situations like this are quite rare to be fair to impact the clutch in any meaningful way. In the 7 years we have been selling mtb oval rings, we have not seen a single claim of clutch being damaged by the oval chainring. If this would be a common thing, we would not be in the place where we are now being the biggest aftermarket manufacturer of oval chainrings in the World.

    • Hey Varaxis, Lyford and Greg. Running an oval ring will increase clutch wear by a small amount while climbing. That said, SRAM now make oval rings and Shimano clutches are adjustable. Do I think the benefit outweighs this for technical MTB? 100%. Here is some math to quantify. Modern 1X bikes have front rings 50T and a long RD cage. That results in about a 30deg angle between upper and lower chain lengths. As such, the front chain ring wrap is ~150deg (not 180). On a 32T ring (with 12% ovality) that chain wrap length varies by about 3.6mm twice per crank revolution. That small variation usually lives in the clutch ‘play’ (ie. not engaging the clutch) but when combined with a full suspension bike the clutch will be more active. Again, the extra wear is super minimal compared with normal clutch movement on a full sus bike but I’m not going to claim it doesn’t exist.

    • That should say “Modern 1X bikes have front rings less than 32T and rear cogs greater than 50T and a long RD cage” The site apparently didn’t like my less than and greater than symbols Ha.

  5. I would like to see the “years of research” documents from absolute black. Because to me, it looks like an exact copy of the rotor ring, without the clocking adjustability. I remeber AB website way before they started making rings overnight, they had a preview of a brake rotor.

    Also, for all the bashing shimano dual cam ring by people who were not there and likely never rode it… back then we were mashing, not pedaling round. They abandoned it because front derailer shifting was compromised with index.

  6. Was osymetric not included because they are twin cam? Not necessarily oval? I ride Osymetric on my TT bike and love them!

  7. I put a an Absolute Black oval ring on my Hightower LT. For me it was magical. I did drop a few teeth six too. I was able to out climb all my typical riding bros’ like never before. I think it also helped to reduce pedal bob as well. Bike just seemed smoother and so much more efficient. It might be that I am 50+ and my leg power is not what it used to be and the oval ring smooths out the torque curve.

  8. FWIW–I’ve been using an AB oval ring for the past 5+ years and a WT oval for the past 2. They are both fantastic, the AB is on my mountain bike, the WT on my cross/gravel bike. I live in fairly steep mountainous terrain and the oval rings seem to be perfect for the punchy climbs that dominate our trails here. The hearsay and vitriol from some of the commenters is ridiculous–go out and ride.

  9. Hi Hamburgi,
    Actually Nino is/was using our oval chainrings on his training bikes for some time. However “S” is making sure he will only use what he is paid for. We are simply not willing to mach the money he receives to sponsor one rider with “just a chainring”. “S” sells whole groupset so for them is money better spent.

    These days professional racing is a business. If you think riders have real choice of equipment I have to disappoint you. There is only few exceptions from this rule. It’s all about money team receives from sponsors. At the end of the day for a Pro team of 30 riders there is another 50 people behind the scenes (mechanics, drivers,coaches, doctors, head of performance, head of science, nutritionists, pr, head of marketing etc etc). They all take salary, same as riders. And then we need to add offices, cars, budget for travelling etc. It’s a well structured company so to speak and the main income is sponsors money. Sponsors are well aware of this “thinking mentality” that whatever sponsored rider uses it must be best. And they spend ridiculous amount of money to get in the bidding game.

    The real tragedy here is when riders are forced to wear certain shoes or saddles or helmet, that doesn’t fit them, just because of a sponsorship deal. Only few teams are bold enough to let riders use whatever shoes they like or the saddle that fits them best. So the next time you see on teams bikes new electronic groupset or suddenly new bike sponsor, is not because x is better than y. But just because someone doubled the sponsorship money.

    Racing on best choice equipment ended at the moment racers started taking money from the sponsors. That was long time ago.

  10. Hi Pinko,
    Thanks for the comment. I think you haven’t been on our website for a while. Here is the link to our science laboratory. This is a good starting point:
    https://absoluteblack.cc/absoluteblack-science-laboratory/
    While we are not showing all the testing we have done as this is proprietary knowledge that we use to build our chainrings, we show few studies we have done or independent Universities have done on our chainrings. Advantages are clear.
    But to sum up what we have done in last 4 years.
    • We have our own science lab with real scientists. These are people with Doctoral degree in biomechanics. Leading scientist is dr Borut Fonda. You can read more on our website.
    • Borut is one of the main contributors of the guidelines “consensus of bike fitting” for the modern bike fitting, which Retul and other brands are relying all their system on. He also later proven that those guidelines were not “one fit all” solution and there is a need of a change which we are now leading.
    • Borut is also a proprietor of Forped pedals. The only scientific grade 3D force measurement system in the World that is capable of accurately measure forces on the pedal in every direction, on top of angles, efficiency, mechanical effectiveness and so on. With such a device we are capable of measuring everything and most importantly measure changes that happen when using different chainrings or different people. Without such a device it’s impossible really to optimize the chainring to perform its best. We are the ONLY company that have such an equipment and a Science lab devoted to pedal optimization. Rest is throwing darts in the dark so to speak.
    • We have invested over 0.5mln eur into the lab to measure everything starting from forces, to 3d position of leg joints, to oxygen consumption and so on.
    • We are officially providing scientific biomechanical optimization services to entire Pro Tour Team UAE and few others (under confidentiality agreement). This gives us the knowledge of how pro riders pedal compared to amateur. Which means we see a full spectrum of pedal kinematics of many thousands of riders. And not surprisingly if you decide to use a certain size of a chainring in certain discipline (eg 32T on mtb) we already know how you will pedal. With such a volume of measurements it’s really clear that certain pedalling style, fitness level etc corresponds to what size of a chainring you are using. It’s not an accident that you chose to use 26 or 36T.
    • We are cooperating with leading Universities in the World that specialize in biomechanics to confirm our own findings and this has resulted in:
    • We have proven that our particular oval chainrings reduce knee joint load leading to less pain when pedalling. This will be published in medical Journal this year.
    • We are leading other studies in biomechanical optimization that we use with Pro Tour riders to improve their mechanical efficiency. I can’t tell you about specifics, but this is what we can call a “pure magic” and we will soon have affordable solution for an average rider as well.
    Because of very long term contracts sponsors have with Pro Tour teams, prohibiting us from mounting ovals on their bikes, we have also developed a system that will give almost same benefits in terms of mechanical efficiency and biomechanical effectiveness using round rings. And this is what we provide to the teams. However, this requires each rider to spend long time in the lab honing the skill under constant monitoring of hundreds of parameters. So in a way one has a choice of spending 5k eur for us to teach you how to pedal round ring efficiently or use our sub 100$ oval chainring and get same result in few weeks on your own.

    Last but not least. Biopace disappeared from the market because it gave riders knee pain and pedalling was never smooth. Not because of shifting issues. The idea was right but concept executed terribly.
    If someone would like to learn how to pedal better first hand you have a chance. We have recently opened up to the public with same scientific biomechanical optimization services that we provide for Pro Tour riders. You can find more information here:
    https://absoluteblack.cc/worlds-best-bike-fitting-services/

    • How come my replies are cancelled?
      Last 4 years designing a ring that was produced in late 2014? Did you change the shape? How come it looks exactly like rotor without the clocking adjustability which is key.

      Enough about biopace, you guys just don’t know.

  11. How do hills impact oval rings? By that I mean when on level ground your position and pedaling is a bit different then when going up a steep climb which makes it seem like the optimal position of the oval is different.

    I also don’t understand how absolute black has a fixed oval making it seem like there is no need to adjust the position but rotor has a wide range of adjustments for their oval

    • Hi Eli,
      absoluteBLACK oval rings shine on the uphills. This is where you are going to see the biggest difference. Every time you need to accelerate like riding uphill, going out of the corner, riding against the wind, sprinting, gives you the benefit. When you ride in the peleton and just cruising you will not see a difference. But every time the uphill comes, gains are very apparent.
      We optimize small and big ring for the road differently. You are correct that the position slightly changes on the uphill (and many other parameters as well) and because of this our small chainring has different orientation to the big ring and also different ovality %. We take all of this into account.
      Like I mentioned in other comments we have measured big number of riders and simulated all riding situations. We have a special indoor platform where we can change the angle of the “road” from 0-25%.This gives us full knowledge about riding behavior, effective force direction, changes in cadence, changes in hip,knee,ankle angles and so on.

      And because of all this knowledge we are not offering a rider a choice of changing the chainring orientation. We make a fixed position by the design. Without sophisticated equipment you are not able to set the chainring orientation correctly given the multi position option on your own. We have tested enough riders on all the fitness levels to see very clearly certain patterns. There is no need for you to experiment with chainring orientation – it’s our job to get it right and this is what you actually pay for when purchasing our product. You pay for years of scientific research and not for DIY kit.

      It’s been proven countless times that humans are simply bad “measuring devices”. This is why we use thermometers, speed sensors, angle sensors, force sensors, cadence sensors and so on. And measuring mechanical efficiency (to optimize chainring orientation) is many times more sophisticated than, lets say, a simple temperature measurement.

      Hope this answers your questions. If you would like to find out more please get in contact through our website.

  12. Any recommendation for use of an oval ring on a trainer? Absolute black says: “We recommend using small oval ring as a starting point” Ao if I do that and have a wheel off kickr that I do structured workouts using erg mode, should I try to mostly use the inner chain ring?

    Is there a list of which power meters work correctly with oval rings? Does pioneer work?

    • Hi again,

      We wrote about purchasing a small chainring first simply because of the price point. If someone is on the fence about trying them or not and not sure if they will like it, we recommend to get cheaper small ring to test first. Then if you like it get the big one.

      But we also offer 30days Satisfaction Guarantee. If within this time period you are not happy and not feeling a difference in your legs we will swap it to round or give a refund. So there is no risk really to try them.

      For the turbo trainers you really need a set (small + big) as it’s not possible to ride just on the small at home to get the miles done.

      Regards Power meters. The difference in readings in normally about 1-2% vs the round ring. But it’s very consistent. So once you move to ovals you just need to take in account that from now on your readings are going to be minimally higher. All power meters have an error of 2% anyway. For training this doesn’t change anything because after 2-3 rides you will know your new “norm” number.
      We also know that more and more power meter manufacturers now offers and option of “oval ring” software update that algorithmically fixes that increase.

    • Hi Eli. It’s personal preference but I run round on my Kickr and oval on my MTB. As I noted above, we see the value of oval rings in low cadence, high torque scenarios. Running round on your trainer will strengthen the muscles associated with these movements. The Kickr power is taken at the hub so will be accurate. Event based powermeters (most crank, pedal spindle ones) typically have bloat of 4-5% so you’ll need to take that into account – I assume your pioneer will fall into this category. Here is what Stages has to say about it.

      https://support.stagescycling.com/en/support/solutions/articles/1000158537-can-i-use-the-stages-power-meter-with-oval-or-osymetric-chain-rings-

      “Mechanically, the Stages Power left-side power meters are 100% compatible for use with Osymetric, Q-Ring, Absoluteblack, and other non-round chain rings.

      Power measurement through a Stages Power meter is event based, where as an event is one complete pedal revolution. Due to the changes in velocity non-round chain rings produce through the course of an ‘event’, you will see that your power will be skewed higher than with a round ring, which has a constant velocity throughout each event. Through our own testing, and using a hub-based meter as a control, we conclude that there will be a 4-5% increase on the readings from a Stages Power meter when used with a non-round chain rings. The difference between the readings will depend on the ovality of the chainring you are using. We recommend that our customers take this into account when changing from round to non-round chain rings, as they may need to adjust their functional threshold power accordingly. “

  13. If anyone is sceptical of modern day ovals just go and buy one and try it, its thats simple. I’m old enough to have used Biopace back in the day and tried an AbsoluteBlack on my 1x 11, and found all the benifits mentioned in the above article. I now have AB ovals on 2 mtb’s and 2 road bikes. One even fitted to the Mrs’s MTB which she can now get up and over a short steep loose climb that she coulnt before, because of wheelspin. However, I was shot down in flames for fitting one to my race BMX, didnt stop me getting my fastest lap at my local track, only 0.5 sec faster, but it was faster 😉

  14. Maybe it’s not a problem to use a clutch derailleur combined with an oval chainring, but I’m thinking that maybe a fluid damper similar to what Sram are using on the AXS road derailleurs would be better.

  15. Hi Jan,
    Every oval is different. Changes in shape, in angle of 1-2deg and ovality of 1-2% are not going to be caught by measuring with the ruler.

    I would also like to point out that Sram, Oneup (and many others) came with their own “version” of oval long time after we became extremely successful. Sram was not even making direct mount round chainrings at the time we were already selling dm ovals and Oneup only had 104bcd round chainrings in their offer.
    The only two companies that were actively selling ovals on the market before we launched ours, were Rotor and Osymetric.

  16. Why can’t someone just use the small chain ring? Erg mode makes it easy as the smart trainer sets the resistance correctly for the workout no matter which chain ring I’m in. So that makes no sense

    Optional software for a power meter? I’m not sure I’m seen anything like that

  17. Come on that’s false. Sure it’s “marginal” but the lower part of the chain still exert forces on the system. The top part make the wheels accelerate but the bottom part slightly slow it. If this force is exerted through a spring without much friction the “lost” force on sprocket is mostly compensated on chainring but with a clutch engaged by an oval ring movement it’s possible some energy (small for sure) is lost in the clutch. In the end it can easily be demonstrated by an energetic approach. If the clutch is moving then it dissipate energy, that energy can only come from the rider, so efficiency is lost. I guess it’s small but the efficiency on oval ring if they exists are small too. So no easy answer here. I still use oval for the improved traction but i know the efficiency part is uncertain.

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